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The basic about Heng Long RC tank battery packs

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  • The basic about Heng Long RC tank battery packs

    Originally posted by keilau View Post
    My Heng Long tank power system had been 3 pieces of Maxamps.com 7.2 volts NiMH pack and a Duratrax Piranha Digital Peak Battery Charger. The Piranha allowed pretty quick charging of the packs and gave actual capacity reading. When all 3 Maxamps packs died and a replacement pack costs $68 each, I know that I have to do something. (Yes, I am aware of many $15, 3000 mAh packs on Amazon which may be very good.) I was never happy with the discharge curve of the NiMH where the voltage drops too fast. I want to try something different.
    The NiMH pack is made up of 6 sub-C NiMH cells to make a 7.2 volt supply. The best sub-C NiMH cell can hold 3000 mAh charge. It is not electrically possible to make higher than 3000 mAh NiMH pack with 6 cells connected in series. Some seller overcharge their pack to make higher capacity claim which will shorten the pack life and is actually dangereous. Smart battery charger is so cheap this day. It is very easy to verify the capacity claim once you have the battery on hand. If you can live with 1.5-2 hours of run time per charge, the NiMH pack is an acceptable cheap choice. Better quality pack should allow 500 or so charge cycles. Shop carefully with reliable brands.

    The Lithium Polymer battery pack is another economical choice. The LiPo is popular with the flying machine crowd and very cheap. An under $15 2200 mAh pack with XT-60 plug can be easily found at Amazon. It is about 4.25" long and fits the HL battery hole comfortably. It gets slightly more than 1.5 hours run time. There is a jump in capacity and size to 5200 mAh and 5.6 inches in length. The 5200 pack is almost the same price as the 2200 pack. I got a pair of GoldBat 5200 for $30, but cannot fit them onto the HL. The 5.6" is shorter than the HL battery hole, but the power cable on the end making it impossible to fit in without cutting the tank chassis.
    (As a matter of principle, I do not modify tank chassis between the sprocket and idler wheel.)

    The best performer is Lithium Ion based pack, but they are getting very expensive and hard to get due to the EV industry. Typically, the pack has 2 18650 or 4 18650 cells which should have 3000 or 6000 mAh capacity respectively. But only if they use premium Li-Ion cells, usually made in Japan or Taiwan. Mato and Admirals are the premium Li-Ion pack brands. The premium 18650 cell is very easy to identify which weights in at 47 grams or more. Cheap, low performance 18650 cell weights about 37-41 grams and holds only about 1000 mAh or less. The Mato and Admirals pack sell for $30 and $60 respectively for the 3000 and 6000 mAh pack. If you ticker with electronics like me, you can build DIY Li-Ion pack at a lot lower cost. I also built 2x 26650 cells pack. They charge up to 4700 mAh and is perfect in size for the HL battery compartment. It gives about 2.5 hours run time. I have not seen any commercial pack using the 26650 yet.


  • #2
    There is so much here I disagree with and that has been left out based on my more then 40 years of RC experience, but everyone is entitled to their own thoughts on the battery topic as it relates to tanks. There must be a dozen threads of this type already and another “Ford vs Chevy vs Toyota” thread is almost pointless.


    Comment


    • #3
      Originally posted by keilau View Post
      It is not electrically possible to make higher than 3000 mAh NiMH pack with 6 cells connected in series. Some seller overcharge their pack to make higher capacity claim which will shorten the pack life and is actually dangereous. Smart battery charger is so cheap this day. It is very easy to verify the capacity claim once you have the battery on hand. If you can live with 1.5-2 hours of run time per charge, the NiMH pack is an acceptable cheap choice. Better quality pack should allow 500 or so charge cycles. Shop carefully with reliable brands.

      What is wrong with you man. You are so far off base here. I know battery science. I had to learn how to charge nearly any battery I came across and make use of it for my equipment in the field.
      There are plenty of brands that offer NiMH 7.2v 6 cell packs in higher than 3000mah capacity. I have purchased several brands in recent years. And yes, my smart charger measures discharge capacity and charged capacity when completed and I regularly get the full if not a tad higher than rated mah rating out of batteries the first year.
      I discharge at 1amp and charge at 1.1amp rate typically. Yes it takes a while but I get nice full capacity without alot of resistance built up in terms of heat in the battery and I typically get a few years out of my better brands of batteries which is many charges, but 500 who are you kidding? Even charging at 1/10C for the least resistance and heat build up causing degredation and maximum life span on a NiMh your not going to get 500 cycles. Your probably not even going to get half of that.
      And yes, I typically get 1.5-2 hours of continuous operating time on a 3-5ah NiMh when charged this way. If you fast charge them, causing a pack to get hot, your going to get a lot less operating time. If you are able to operate at periods of time longer than this then you are performing near miracles with your batteries or driving very slow the whole time. And I mean driving the whole time. I just yesterday went out and drove for about an hour and half with about 1/3 of my time at full speed maneuvering.

      Even my LiPo batteries for helis have not lasted 250 charges and I charge them at 50%C and they stay quite cool. I got to about 150-200 charges based on my fight schedule before I experienced cell degredation and drastic loss of performance. My local shop was shocked by how much life I got out of the LiPo battery until I needed a new one.
      RC tank parts and accessories I make
      www.RichardSJohnson.net/id28.html

      Comment


      • #4
        I like my 18650 2S2P and 2S packs I got from AliExpress. I think Rich had a bad experience with not getting them after ordering them, but I now have 8 of the 2S2P packs and like 5 of the 2P packs. I removed the protective covering and they use LG cells. I got them for about $16/pack for the 2S2P and like half that for the 2S packs. I can charge the larger 7000mAh packs at 5A and they don't get warm in the slightest. Of course I charge the 2S packs at like 2A since they are rated at like 3500mAH. I don't use NiMH at all anymore unless they are in my GPA, M16 half-track, or my MRAPs. The 2S packs are just like the HL Li-Ion packs coming with their tanks only higher capacity. I did have one bad 2S pack, but that was bad when I got it from HL. It doesn't register any voltage when plugged into the battery voltage alarm. I can also use the HL and AliExpress 2S packs in my Flysky Q X7 transmitter by plugging the battery in using it's balance plug.

        Comment


        • #5
          Ahh. Batteries. Love/hate relationship with them for me. They are a large part of why the sweeping majority of my fleet is ICE. Every single one of my 30+ RC aircraft? Nitro. Both of my boats? Nitro. Sweeping majority of my cars? Nitro. I'd even have a fuel powered tank if I could find one(And I might just try to build one if I can find a Kyosho Nitro Blizzard transmission laying around someplace~). It's so convenient being able to just pour or pump more runtime in and keep right on going; I will often run my cars for over an hour continuously and only stop because their air filters are so badly clogged with mud/dust that the engines are barely able to breathe anymore. My planes...I have on more than one occasion landed, refuelled, gone right back up again. That being said, they all still need batteries to run their receivers, servos, and I do have a couple of electrics in my collection(My KV-1E being one of them). And that means I've had my fair share of encounters with these chemical storage tanks.

          How I see batteries:

          Alkalines: Money sink. Only use in super low draw devices like TV remotes. Very little use in radio control IMO. Not fond of having to put six duracells in my HL KV-1E's radio, but it shouldn't draw much power so they should last. Also don't like disposable things in general, which these are.

          NiMH/NiCD: Useless garbage. Their innate self discharge, horrid discharge curve, incredibly slow charging, and fussy nature makes them a total non-starter for me. I see them as little more than paperweights, as climbing obstacles. I lost count years ago how many times my old NiCD and NiMH based glow drivers let me down. As a result I won't even think about using a nickel battery nor will I ever recommend others use one. They're just terrible.

          SLA: Probably not a commonly used battery chemistry in our tanks, but they do pop up in the hobby from time to time. My field box has one. They....have their uses. I only ever use these to start engines and most of mine are rated by cold cranking amps. The one in my field box? It won't take a charge anymore.

          Lithium-Iron-Phosphate. Li-FE. My favorite battery chemistry. They're the most docile of lithium chemistries, they pack a good capacity for their weight, and their per-cell voltage is roughly twice that of Nickel based packs. I use a LOT of 2s LiFE packs to run the receivers, servos in all of my fuel burning RCs, as well as my Futaba 10J, 6J radios. Amazing batteries. Like all lithium chemistries, they need to be charged properly, but they are the easiest going, most laid back of lithium chemistries and they're a godsend for nitro nuts like myself. I probably have 40+ packs!

          Lithium Polymer: The mean bastards. If mishandled, these things will burn your house down and laugh at you the whole time. But they will do some insane stuff. A humble 3s2200 LiPO like you might find in the battery bay of a cheap 40-50" wingspan foamy will jump start your car without even thinking about it. These things are AMAZING for high demand devices and the cells will happily push more amps than the wiring can handle. Brushless RC car guys will often choose their connectors based on melt resistance because these batteries are more than capable of permanently welding Deans, Tamiya plugs together in particular. I have a few LiPO packs and, as long as the proper charging/storage precautions are taken, they are perfectly safe. And you find them in a lot of higher demand devices; your phone probably has one in it my glow plug driver has one in it. Great batteries....but don't get complacent around these things.

          Lithium Ion: Middle of the road in all regards. Ubiquitous. You find these things in EVERYTHING these days, from cheap crappy Amazon flashlights to 80,000+ dollar electric cars you can sit in. Easy to get quality cells; any smoke shop will sell you Samsungs or LG 18650s if you want to make your own packs and/or modify your tank's battery tray to accept loose cells. This is also what Heng Long is including in the box these days; my KV-1E 7.0 that I bought just a week ago came with a 2s1800 Li-Ion pack comprised of a pair of 18650s.

          Given the current demands of these tanks, Li-Ion or Li-FE batteries are pretty much perfect for them. They don't draw enough current to justify putting a Li-PO in one. A 3s LiFE would be ideal I think, but 2s2p, 2s3p, even 2s4p Li-Ion would also be great. Pack more mAh in there play for longer!

          Comment


          • #6
            Originally posted by tank_me View Post
            I like my 18650 2S2P and 2S packs I got from AliExpress. I think Rich had a bad experience with not getting them after ordering them, but I now have 8 of the 2S2P packs and like 5 of the 2P packs. I removed the protective covering and they use LG cells. I got them for about $16/pack for the 2S2P and like half that for the 2S packs. I can charge the larger 7000mAh packs at 5A and they don't get warm in the slightest. Of course I charge the 2S packs at like 2A since they are rated at like 3500mAH. I don't use NiMH at all anymore unless they are in my GPA, M16 half-track, or my MRAPs. The 2S packs are just like the HL Li-Ion packs coming with their tanks only higher capacity. I did have one bad 2S pack, but that was bad when I got it from HL. It doesn't register any voltage when plugged into the battery voltage alarm. I can also use the HL and AliExpress 2S packs in my Flysky Q X7 transmitter by plugging the battery in using it's balance plug.
            Can you share the link to the "18650 2S2P and 2S pack" seller"? The Mato and MotionRC packs are good performers but too expensive. I cannot find Samsung or LG single cells at reasonable price anywhere any longer. I use a SkyRC B6 charger programmed to stop charging at 8.2 volts. So I get 2800 mAh with the 2S pack and 5700 mAh with the 2S2P pack. I trade the slightly small charge for longer battery life.

            Comment


            • #7
              Originally posted by RichJohnson View Post

              What is wrong with you man. You are so far off base here. I know battery science. I had to learn how to charge nearly any battery I came across and make use of it for my equipment in the field.
              There are plenty of brands that offer NiMH 7.2v 6 cell packs in higher than 3000mah capacity. I have purchased several brands in recent years. And yes, my smart charger measures discharge capacity and charged capacity when completed and I regularly get the full if not a tad higher than rated mah rating out of batteries the first year.
              I discharge at 1amp and charge at 1.1amp rate typically. Yes it takes a while but I get nice full capacity without alot of resistance built up in terms of heat in the battery and I typically get a few years out of my better brands of batteries which is many charges, but 500 who are you kidding? Even charging at 1/10C for the least resistance and heat build up causing degredation and maximum life span on a NiMh your not going to get 500 cycles. Your probably not even going to get half of that.
              And yes, I typically get 1.5-2 hours of continuous operating time on a 3-5ah NiMh when charged this way. If you fast charge them, causing a pack to get hot, your going to get a lot less operating time. If you are able to operate at periods of time longer than this then you are performing near miracles with your batteries or driving very slow the whole time. And I mean driving the whole time. I just yesterday went out and drove for about an hour and half with about 1/3 of my time at full speed maneuvering.

              Even my LiPo batteries for helis have not lasted 250 charges and I charge them at 50%C and they stay quite cool. I got to about 150-200 charges based on my fight schedule before I experienced cell degredation and drastic loss of performance. My local shop was shocked by how much life I got out of the LiPo battery until I needed a new one.
              NiMH pack can last near 500 cycle use if it is not overcharged and drained to near zero charge. A 5 Ah NiMH pack should last 2.5 hours full speed run time, but it does not exist. I do not use LiPo packs because of the lack of protection circuit. Over charging and over draining any pack will sure shorten its life of charge cycles.

              Li-Ion is the more ideal pack for HL tanks. It stops discharge at 6 volts or so. If not overcharged, it can easily last over 7-800 cycles. The manufacturer's 1000 cycles claim is probably an overstatement. But I cannot find Samsung or LG cells anymore.

              Comment


              • #8
                Originally posted by keilau View Post

                NiMH pack can last near 500 cycle use if it is not overcharged and drained to near zero charge. A 5 Ah NiMH pack should last 2.5 hours full speed run time, but it does not exist. I do not use LiPo packs because of the lack of protection circuit. Over charging and over draining any pack will sure shorten its life of charge cycles.

                Li-Ion is the more ideal pack for HL tanks. It stops discharge at 6 volts or so. If not overcharged, it can easily last over 7-800 cycles. The manufacturer's 1000 cycles claim is probably an overstatement. But I cannot find Samsung or LG cells anymore.
                LiPO is a bit overkill for one of these tanks, I agree, but the Heng Long 7.0 MCU has a built in lipo cutoff that can automatically detect how many cells are in the tray. I found this out last night when I was working on/testing my smoker after making some tweaks to its plumbing; the included 2s 18650 pack died so I threw a random 3s1300 lipo in there and that also zonked. Bummed a 3s2200 from my nitro airplane starter and that, too, tripped the LVC. Interestingly, LVC on the tank is more conservative than the protection inside the 18650 cells that shipped with the tank! That protection never tripped.

                When I put my 3s2200 on to charge, it was down to around 3.3v/cell. That's on par with what most hobby grade electric RC cars run them down to and is fine on longevity, especially with a fairly low draw device like one of these tanks.

                If sound and smoke are on, they stop. MCU plays the engine shutdown sound. Traction motors shut off. LED goes into flash mode. That's how you know you tripped LVC.

                I can't speak for older HL MCUs, Tamiya MCUs, Taigen/Torro MCUs, but the HL 7.0 has built in native LiPO cutoff for 2-cell and 3-cell packs. It's safe to use them in one.

                Comment


                • #9
                  Originally posted by keilau View Post

                  Can you share the link to the "18650 2S2P and 2S pack" seller"?
                  This was the seller I got mine from. The do state they are NCR18650GA which are Sanyo or Panasonic cells, but the pack I opened was LGs. I chose these because they had the XT60 connector on them and have a balance plug for charging.

                  https://www.aliexpress.us/item/3256801093189430.html?spm=a2g0o.productlist.main.1 .95a31d5clhjqVR&algo_pvid=5e17385a-d96a-4262-857f-dcee37eeda80&algo_exp_id=5e17385a-d96a-4262-857f-dcee37eeda80-0&pdp_ext_f=%7B%22sku_id%22%3A%22120000155605961 25 %22%7D&pdp_npi=2%40dis%21USD%2128.14%2116.88%21%21 %21%21%21%40211bf4c516692507384475401d0766%2112000 015560596125%21sea&curPageLogUid=mabeeZEmFmK3

                  Comment


                  • #10


                    Jennyc6 is correct. No worries running Lipos with the new 6.0 and up systems from an electrical standpoint.

                    The issues most are missing here is that the vast majority of those buying HL tanks have little to NO RC EXPERIENCE and telling them to use Lipos is not good advice. Lipos and Li-ion batteries are best left to those with moderate to advanced RC skills. Hence why I only recommend NiMH batteries, I have to assume from experience that most readers are relatively new to RC. NiMH are the safest and easiest for a new to RC person to handle and abuse. As there experience level grows then they can branch out should they find the need to.

                    I hear often “Hey Rubicon why does your tank run so much better then mine when they are set up similar”. Because I run a tune of battery to tank to optimize handling and performance. NiMH being available in more voltage options (7.2 / 8.4 / 9.6) have a few advantages with the 6.0-7.1 HL MFUs (and with Tamiya DMD/MFUs) that the others do not. These advantages come into play once a given level of understanding of how to set up a tank (overall weight, weight balance, metal suspension, track type and patterns , road wheels, motors and gearboxes ...) for achieving smooth performance (fast and slow) and handling (turning/climbing) come into play. Having the right voltage range, not to much, not to little makes the difference between a good handling tank and a great handling tank. NiMHs simply are superior for tuning/making great handling tanks.

                    Now if one places a higher value on run time and number of cycles a battery can undergo then a Lipo or Li-Ion is probably best for them as long as they have the experience to properly and safely handle them.






                    .









                    Comment


                    • #11
                      Originally posted by JennyC6 View Post

                      LiPO is a bit overkill for one of these tanks, I agree, but the Heng Long 7.0 MCU has a built in lipo cutoff that can automatically detect how many cells are in the tray. I found this out last night when I was working on/testing my smoker after making some tweaks to its plumbing; the included 2s 18650 pack died so I threw a random 3s1300 lipo in there and that also zonked. Bummed a 3s2200 from my nitro airplane starter and that, too, tripped the LVC. Interestingly, LVC on the tank is more conservative than the protection inside the 18650 cells that shipped with the tank! That protection never tripped.

                      When I put my 3s2200 on to charge, it was down to around 3.3v/cell. That's on par with what most hobby grade electric RC cars run them down to and is fine on longevity, especially with a fairly low draw device like one of these tanks.

                      If sound and smoke are on, they stop. MCU plays the engine shutdown sound. Traction motors shut off. LED goes into flash mode. That's how you know you tripped LVC.

                      I can't speak for older HL MCUs, Tamiya MCUs, Taigen/Torro MCUs, but the HL 7.0 has built in native LiPO cutoff for 2-cell and 3-cell packs. It's safe to use them in one.
                      Very useful information. I have not tested my HL 7.0 LVC yet. Last week, I found out that the 6.0S LVC tripped at 6.2 volt when the tank is on flash mode with a Li-Ion pack. I use only DIY Li-Ion packs with the HL tanks.

                      I have one each of the GoldBat LiPo 2S2200 and 3S3000. I don't use them on the HL. I accidentally fully discharged the 2S2200 on an older MCU. It was dead. I revived it using trigger charge to holding 1700 mAh. I am not sure how long it can last. I feel more secure with the Li-Ion packs. Don't use NiMH anymore due to its nonlinear discharge curve.

                      Comment


                      • #12
                        Originally posted by tank_me View Post
                        But these packs will not fit the HL battery compartment. For the HL tank, the cells need to be arranged as this:
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                        When I built these in early 2021, I paid $10 for 4 of the EBL cells and got a 6000 mAh pack. Now, similar single cell is more than $10 EACH. The parallel charge plug is for use with a B6 parallel charger.

                        Comment


                        • #13
                          Originally posted by Rubicon99 View Post

                          Jennyc6 is correct. No worries running Lipos with the new 6.0 and up systems from an electrical standpoint.

                          The issues most are missing here is that the vast majority of those buying HL tanks have little to NO RC EXPERIENCE and telling them to use Lipos is not good advice. Lipos and Li-ion batteries are best left to those with moderate to advanced RC skills. Hence why I only recommend NiMH batteries, I have to assume from experience that most readers are relatively new to RC. NiMH are the safest and easiest for a new to RC person to handle and abuse. As there experience level grows then they can branch out should they find the need to.

                          I hear often “Hey Rubicon why does your tank run so much better then mine when they are set up similar”. Because I run a tune of battery to tank to optimize handling and performance. NiMH being available in more voltage options (7.2 / 8.4 / 9.6) have a few advantages with the 6.0-7.1 HL MFUs (and with Tamiya DMD/MFUs) that the others do not. These advantages come into play once a given level of understanding of how to set up a tank (overall weight, weight balance, metal suspension, track type and patterns , road wheels, motors and gearboxes ...) for achieving smooth performance (fast and slow) and handling (turning/climbing) come into play. Having the right voltage range, not to much, not to little makes the difference between a good handling tank and a great handling tank. NiMHs simply are superior for tuning/making great handling tanks.

                          Now if one places a higher value on run time and number of cycles a battery can undergo then a Lipo or Li-Ion is probably best for them as long as they have the experience to properly and safely handle them.
                          I started with HL tank in the mid 2000's but stopped due to frequent business travel. When I returned in 2021 after I retired, I got a lot of help from your good advice and really appreciate it. I do not recommend LiPo to new RC tank user due to the lack of protection circuit, but you cannot avoid it since almost all flying RC model use it. Li-Ion is a different story. The HL tank is a low current discharge machine and unlikely to overheat. Intelligent balance charger is cheap to get and a must have to use Li-Ion pack.

                          Basic battery technology has been stable for the last 20 years, but the market continues to change rapidly. Li-Ion pack used to be affordable, but no longer so. They are still the performance leader. My latest HL purchased this year both came with Li-Ion of the 1100 mAh capacity.

                          Comment


                          • #14
                            Originally posted by keilau View Post

                            But these packs will not fit the HL battery compartment. For the HL tank, the cells need to be arranged as this:
                            When I built these in early 2021, I paid $10 for 4 of the EBL cells and got a 6000 mAh pack. Now, similar single cell is more than $10 EACH. The parallel charge plug is for use with a B6 parallel charger.
                            I don't care that they don't fit in the stock battery box as I normally cut the battery box out and pour resin in the bottom of my chassis to stiffen it up after removing the battery box. I then use velcro on the battery and on the bottom of the tank to hold them in place.

                            Comment


                            • #15
                              Originally posted by keilau View Post

                              Very useful information. I have not tested my HL 7.0 LVC yet. Last week, I found out that the 6.0S LVC tripped at 6.2 volt when the tank is on flash mode with a Li-Ion pack.
                              The 7.0 MFU seems to be pretty smart as it didn't take either of my 3s LiPOs too far down. It cut off at much higher voltages than yours did on a Li-Ion pack.
                              I use only DIY Li-Ion packs with the HL tanks.
                              I don't, but I have spitballed a mental doodle about modifying the battery tray to accept loose 18650 cells. Or even 21700s. I can readily get either cell at my local vape shop in good quality, good capacity.
                              I accidentally fully discharged the 2S2200 on an older MCU. It was dead. I revived it using trigger charge to holding 1700 mAh. I am not sure how long it can last.
                              With how cheap they are I'd just retire it if I were you. I have a similar problem with my engine starter for my nitro planes; it's just a big ol' brushed DC motor with a switch in the hot line. No electronics whatsoever. I use 3s2200 LiPOs on it because it needs the punch they provide and on occasion have run one way low. Nickel Trickel revivals seldom last more than a few charge cycles before they start to puff up.

                              I feel more secure with the Li-Ion packs. Don't use NiMH anymore due to its nonlinear discharge curve.
                              My only qualm about using a LiPO in my tanks is that it's overkill for the demands they put on them. I'll never use nickel though. I have 100% obsoleted all nickel batteries out of my hobby; I don't even use that chemistry to light my glow plugs anymore.

                              I do all forms of RC, not just tanks, and in doing so I've found myself one of the four flight instructors at my local RC aeromodelling club. You don't have a choice with aircraft. Nickel batteries are too heavy and too weak for flying, LiFE flies as receiver power for fuel burners, and Li-Ion can't supply the current demands. It's....not difficult to teach a total newbie how to handle unprotected lithium batteries without burning their house down.

                              Originally posted by Rubicon99 View Post
                              The issues most are missing here is that the vast majority of those buying HL tanks have little to NO RC EXPERIENCE and telling them to use Lipos is not good advice. Lipos and Li-ion batteries are best left to those with moderate to advanced RC skills. Hence why I only recommend NiMH batteries, I have to assume from experience that most readers are relatively new to RC. NiMH are the safest and easiest for a new to RC person to handle and abuse. As there experience level grows then they can branch out should they find the need to.
                              They don't have a choice these days. Heng Long is including a 2s1800 Li-Ion pack in their tanks now, alongside one of those god awful USB balance lead chargers. And it's not like it's difficult to teach newbies how to handle Lithium batteries without burning their house down. It isn't some mystical long-lost art that only 20+ year RC veterans who's houses smell of castor oil and look like hobby shops know. It's pretty simple really.

                              * Never over-discharge
                              * Never over-charge
                              * Store at half charge if not being used for >2 weeks
                              * ALWAYS balance charge on a smart charger set to the correct lithium profile
                              * Charge in a fireproof location.

                              There. That's it. That's all they need to know. So rather than fearmongering and trying to promote terrible, obsolete, and frustrating battery chemistries, how about just educating newbies on proper lithium battery care so they can enjoy the objectively better in every way performance that comes right there in the box when they buy their new tank?

                              I've seen the same arguments you put forth when it comes to monster trucks and foam airplanes and it's always countered by 'well just teach them then'. It's not even an option with the aircraft because NiMHs are just too heavy to fly.....and as I'm one of the flight instructors for my local club I'm often teaching total novices who've never run anything more advanced than a crappy WalMart toy grade how to run hobby grade electronics. It legit takes about 15-20 minutes to do it.

                              I hear often “Hey Rubicon why does your tank run so much better then mine when they are set up similar”. Because I run a tune of battery to tank to optimize handling and performance. NiMH being available in more voltage options (7.2 / 8.4 / 9.6) have a few advantages with the 6.0-7.1 HL MFUs (and with Tamiya DMD/MFUs) that the others do not. These advantages come into play once a given level of understanding of how to set up a tank (overall weight, weight balance, metal suspension, track type and patterns , road wheels, motors and gearboxes ...) for achieving smooth performance (fast and slow) and handling (turning/climbing) come into play. Having the right voltage range, not to much, not to little makes the difference between a good handling tank and a great handling tank. NiMHs simply are superior for tuning/making great handling tanks
                              You get far better results just practicing driving the thing than you ever will fiddlefarting with battery voltages, especially with such an inferior chemistry as NiMH and its terrible discharge curve. Was half the reason I took my KV-1 to the local park yesterday after work; just get some time on the sticks driving the thing. The more I drive it the better I get at making it do what I want it to do.

                              The next biggest upgrade would be radio. I'll grant the radio Heng Long includes is useable...hell it's better quality than what Traxxas includes with 100MPH supercar RTRs shockingly enough...but it leaves a lot to be desired. Maybe I'm spoiled by all the Futaba radios hanging on my wall...4YF student box, 6J, 10J, 16IZ...but I could see a LOT of improvement in performance of one of these tanks by ditching the Heng Long electronics entirely and moving my tanks to my 16IZ. Indeed, that is a future plan for my KV-1E alongside any future tanks I buy. Clark control board, Futaba S-FHSS receiver.

                              Next upgrade is battery capacity. The included pack is pretty good, performance wise....driving it I can't really tell where the remaining capacity is which means a nice and flat discharge curve as one expects from a Lithium battery...but 1800mAh is pretty pathetic and that tiny little pair of 18650s leaves a TON of unused space in the battery tray.​

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                              • #16
                                Originally posted by tank_me View Post

                                I don't care that they don't fit in the stock battery box as I normally cut the battery box out and pour resin in the bottom of my chassis to stiffen it up after removing the battery box. I then use velcro on the battery and on the bottom of the tank to hold them in place.
                                Confused! Do you mean you Velcro the battery under the bottom of the tank? I cannot see enough ground clearance there. If the battery is inside the tank, how do you recharge it?

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                                • #17
                                  I’m sure inside. Many use magnets to make removing the top easier.

                                  Comment


                                  • #18
                                    Originally posted by JennyC6 View Post
                                    The 7.0 MFU seems to be pretty smart as it didn't take either of my 3s LiPOs too far down. It cut off at much higher voltages than yours did on a Li-Ion pack. I don't, but I have spitballed a mental doodle about modifying the battery tray to accept loose 18650 cells. Or even 21700s. I can readily get either cell at my local vape shop in good quality, good capacity.
                                    With how cheap they are I'd just retire it if I were you. I have a similar problem with my engine starter for my nitro planes; it's just a big ol' brushed DC motor with a switch in the hot line. No electronics whatsoever. I use 3s2200 LiPOs on it because it needs the punch they provide and on occasion have run one way low. Nickel Trickel revivals seldom last more than a few charge cycles before they start to puff up.

                                    My only qualm about using a LiPO in my tanks is that it's overkill for the demands they put on them. I'll never use nickel though. I have 100% obsoleted all nickel batteries out of my hobby; I don't even use that chemistry to light my glow plugs anymore.

                                    I do all forms of RC, not just tanks, and in doing so I've found myself one of the four flight instructors at my local RC aeromodelling club. You don't have a choice with aircraft. Nickel batteries are too heavy and too weak for flying, LiFE flies as receiver power for fuel burners, and Li-Ion can't supply the current demands. It's....not difficult to teach a total newbie how to handle unprotected lithium batteries without burning their house down.



                                    They don't have a choice these days. Heng Long is including a 2s1800 Li-Ion pack in their tanks now, alongside one of those god awful USB balance lead chargers. And it's not like it's difficult to teach newbies how to handle Lithium batteries without burning their house down. It isn't some mystical long-lost art that only 20+ year RC veterans who's houses smell of castor oil and look like hobby shops know. It's pretty simple really.

                                    * Never over-discharge
                                    * Never over-charge
                                    * Store at half charge if not being used for >2 weeks
                                    * ALWAYS balance charge on a smart charger set to the correct lithium profile
                                    * Charge in a fireproof location.

                                    There. That's it. That's all they need to know. So rather than fearmongering and trying to promote terrible, obsolete, and frustrating battery chemistries, how about just educating newbies on proper lithium battery care so they can enjoy the objectively better in every way performance that comes right there in the box when they buy their new tank?

                                    I've seen the same arguments you put forth when it comes to monster trucks and foam airplanes and it's always countered by 'well just teach them then'. It's not even an option with the aircraft because NiMHs are just too heavy to fly.....and as I'm one of the flight instructors for my local club I'm often teaching total novices who've never run anything more advanced than a crappy WalMart toy grade how to run hobby grade electronics. It legit takes about 15-20 minutes to do it.



                                    You get far better results just practicing driving the thing than you ever will fiddlefarting with battery voltages, especially with such an inferior chemistry as NiMH and its terrible discharge curve. Was half the reason I took my KV-1 to the local park yesterday after work; just get some time on the sticks driving the thing. The more I drive it the better I get at making it do what I want it to do.

                                    The next biggest upgrade would be radio. I'll grant the radio Heng Long includes is useable...hell it's better quality than what Traxxas includes with 100MPH supercar RTRs shockingly enough...but it leaves a lot to be desired. Maybe I'm spoiled by all the Futaba radios hanging on my wall...4YF student box, 6J, 10J, 16IZ...but I could see a LOT of improvement in performance of one of these tanks by ditching the Heng Long electronics entirely and moving my tanks to my 16IZ. Indeed, that is a future plan for my KV-1E alongside any future tanks I buy. Clark control board, Futaba S-FHSS receiver.

                                    Next upgrade is battery capacity. The included pack is pretty good, performance wise....driving it I can't really tell where the remaining capacity is which means a nice and flat discharge curve as one expects from a Lithium battery...but 1800mAh is pretty pathetic and that tiny little pair of 18650s leaves a TON of unused space in the battery tray.​
                                    HL switching to Li-Ion had simply to do with economics and supply then achieving better running performance or ease of use. It also has lead to a higher battery failure rate and warranty claims that are still continuing. In fact HL is considering stopping supplying batteries with their tanks do to these and other issues. Recently several HL tanks ordered did not even come with batteries and had addendums in the instructions manuals regarding batteries. This would seem to indicate that HL might have started deleting the once included battery.

                                    Now it is clear you don’t know me, thats ok and what I have done in the hobby and RC tank industry. So I am going to be little arrogant about it here for the moment. I know 1/16 rc tanks not just HL better then the vast majority of people here and can only sit back and be entertained at this point by what is being written on this thread and others threads of recent by what is to me RC tank beginners. All making the same mistake that have been being made for years by others (myself included) and ending up with the same mediocre results over and over and over. It’s only when stepping away from the pack that real gains are made. Sometimes this means taking a step back to take three steps forward. New is not always best.

                                    So believe what you like about batteries for RC tanks and be happy with the overall mediocrity results that come from a one size fits all way of thinking that new is best. Not saying Lipos and Li-Ion aren’t good batteries, just that they are not as good as NiMH for tuning a tanks performance and getting the most out of the basic HL or Tamiya control systems.























                                    Comment


                                    • #19
                                      Originally posted by keilau View Post

                                      Confused! Do you mean you Velcro the battery under the bottom of the tank? I cannot see enough ground clearance there. If the battery is inside the tank, how do you recharge it?
                                      Nope. Velcro'd to the bottom of the tank on the inside where ever I want since the battery box is gone. The tank top is connected using magnets. This is an example (my HL ZTZ-99) of a battery box removed resin poured bottom hull with magnets installed on the posts that hold the tank together and the battery mounted in the front to offset the weight in the back. The second pic shows where all the magnets were installed. I always remove batteries to recharge my tanks.
                                      Attached Files

                                      Comment


                                      • #20
                                        Originally posted by tank_me View Post

                                        Nope. Velcro'd to the bottom of the tank on the inside where ever I want since the battery box is gone. The tank top is connected using magnets. This is an example (my HL ZTZ-99) of a battery box removed resin poured bottom hull with magnets installed on the posts that hold the tank together and the battery mounted in the front to offset the weight in the back. The second pic shows where all the magnets were installed. I always remove batteries to recharge my tanks.
                                        Very interested. What do I need to know to successfully implement the magnetic attachment? The type of magnet and how to mount them on the post? Are there any detailed link or youtube upload?

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