Russian T-90 battery options

[cmdrcody]

What is the maximum dimension size for a battery to fit into the Russian T-90 tank battery compartment?
Can you use both Li-ion and LiPo 2S 7.4V type batteries with the XT 60 connector for powering the tank?
Specifically, would the RDQ Series 7.4V 2S 5000mAh 5C TX16S Compatible LiPo Battery - XT60 or the NHX RC 2S 7.6V 5200mAh 150C HV + Graphene Shorty LiPo Battery w/5mm Bullets / XT60 work well in this tank?
https://www.racedayquads.com/product...o-battery-xt60

https://nitrohobbies.com/nhx9003xt60/

[keilau]

What is the maximum dimension size for a battery to fit into the Russian T-90 tank battery compartment?
Can you use both Li-ion and LiPo 2S 7.4V type batteries with the XT 60 connector for powering the tank?
Specifically, would the RDQ Series 7.4V 2S 5000mAh 5C TX16S Compatible LiPo Battery - XT60 or the NHX RC 2S 7.6V 5200mAh 150C HV + Graphene Shorty LiPo Battery w/5mm Bullets / XT60 work well in this tank?
https://www.racedayquads.com/product...o-battery-xt60

https://nitrohobbies.com/nhx9003xt60/

The RDQ is a very interesting option if the claimed capacity can be verified. It should fit a standard Heng Long battery well fine and has no need for chassis modification. However, it is designed for transmitter use which requires very little current. Will this 5C battery have enough output to drive 2x 380 motors? The answer is probably not. They are high internal resistance battery for very low discharge rate. A high risk of fire.

You can find some useful information on battery in this thread.
The basic about Heng Long RC tank battery packs - Hobby Squawk RC Forum for Airplanes, Boats, Cars, Helicopters, Tanks, and Trucks

[cmdrcody]

The RDQ is a very interesting option if the claimed capacity can be verified. It should fit a standard Heng Long battery well fine and has no need for chassis modification. However, it is designed for transmitter use which requires very little current. Will this 5C battery have enough output to drive 2x 380 motors? The answer is probably not. They are high internal resistance battery for very low discharge rate. A high risk of fire.

You can find some useful information on battery in this thread.
The basic about Heng Long RC tank battery packs - Hobby Squawk RC Forum for Airplanes, Boats, Cars, Helicopters, Tanks, and Trucks

The Russian T-90 & T-72 takes a battery half as long as all the other Heng Long RC tanks. That is why I would want to install a battery that has more mAh than the 1800mAh that comes with the tank. Especially if I want to install the all metal threads and wheels. Can only fit a 2S (two cell) battery.

[Rubicon99]

The last paragraph above in post # 2 is incorrect. For the simple reason if it was true manufactures would be quickly sued for false advertising especially in the US under the consumer protection laws. The fact is they are not, because the batteries do and can hold more then 3000 mah.

That’s not saying the batteries might have only 3000 useable (at full rated voltage 7.2/8.4/.9.6 before volts start to drop off) of say the peak 4000 to 5000 they are advertised at holding. But the fact is they hold the 4000-5000.

[keilau]

I use home built battery packs for my tanks. Half of them are 2S 26650 and half are 2S2P 18650. The only commercial packs are 3x 2S 18650 that came with the tank purchases in the last 1.5 year.

The first one came with German Leopard 2A6 was encased in a plastic hard shell to simulate the NiMH pack. The later one with T34 and Sherman are in common wrap package. HL rate them all as 1800 mAh. But the way I use them, they are only 800 to 1100 mAh as measured by the B6 iMAX charger which allows them to run the tanks with heavy tracks at full top speed for about half an hour. Typical normal on-off operation run time is much longer.

I charge the pack to no more than 8.2 volts and the HL MFU stops when voltage drop to about 6 volts. Over the years, I learn that I can recharge the Li-Ion pack to several hundred cycles by avoiding overcharge and overdischarge them.

Using the same methodology, my home built packs are rated at 4800 and 5600 mAh. They can run the HL at full speed for 2 or 3 hours. The key to the long run time is to use premium Li-Ion cells such as the Panasonic or Sanyo NCR18650. I use EBL cells and get similar results. I have not use NiMH or NiCd pack for many years and cannot comment on their performance. I like the Li-Ion pack much better.

[cmdrcody]

I use home built battery packs for my tanks. Half of them are 2S 26650 and half are 2S2P 18650. The only commercial packs are 3x 2S 18650 that came with the tank purchases in the last 1.5 year.

The first one came with German Leopard 2A6 was encased in a plastic hard shell to simulate the NiMH pack. The later one with T34 and Sherman are in common wrap package. HL rate them all as 1800 mAh. But the way I use them, they are only 800 to 1100 mAh as measured by the B6 iMAX charger which allows them to run the tanks with heavy tracks at full top speed for about half an hour. Typical normal on-off operation run time is much longer.

I charge the pack to no more than 8.2 volts and the HL MFU stops when voltage drop to about 6 volts. Over the years, I learn that I can recharge the Li-Ion pack to several hundred cycles by avoiding overcharge and overdischarge them.

Using the same methodology, my home built packs are rated at 4800 and 5600 mAh. They can run the HL at full speed for 2 or 3 hours. The key to the long run time is to use premium Li-Ion cells such as the Panasonic or Sanyo NCR18650. I use EBL cells and get similar results. I have not use NiMH or NiCd pack for many years and cannot comment on their performance. I like the Li-Ion pack much better.

Have you read all the previous posts before you made your post?
The Russian T-90 & T-72 takes a battery half as long as all the other Heng Long RC tanks. That is why I would want to install a battery that has more mAh than the 1800mAh that comes with the tank. Especially if I want to install the all metal threads and wheels. Can only fit a 2S (two cell) battery.
Click on this and go to 11 minutes into the video: https://www.youtube.com/watch?v=2_jTy1Yaj1A
Then you will see what I'm talking about.

[SoCalBobS]

Just buy the 3500mah shorty packs from Motion RC. I use them in my T-90 all the time.

[cmdrcody]

Just buy the 3500mah shorty packs from Motion RC. I use them in my T-90 all the time.

They are out of stock. Otherwise, I would not be looking for other battery options

[tank_me]

Personally when I still had the battery box intact in my T-72 I cut the top of it off and installed on of the 2S2P batteries I use in all my other tanks. You can see how the battery box was cut in the pic below.

[keilau]

Have you read all the previous posts before you made your post?
The Russian T-90 & T-72 takes a battery half as long as all the other Heng Long RC tanks. That is why I would want to install a battery that has more mAh than the 1800mAh that comes with the tank. Especially if I want to install the all metal threads and wheels. Can only fit a 2S (two cell) battery.
Click on this and go to 11 minutes into the video: https://www.youtube.com/watch?v=2_jTy1Yaj1A
Then you will see what I'm talking about.

Yes, I understand that the T-90 and T-72 only take 2S Li-Ion battery and NO 2S2P. The HL stock pack are actually 1100 mAh, NOT 1800 as HL stated. However, you can still get half an hour top speed continuous or longer in normal operation. You just need a good balance charger. You can get 3 times the run time using the Admirals 2S Li-Ion. Until you modify the chassis to accept bigger battery pack like tank_me does. It is as long a run time as you can get.

I understand that MotionRC is currently sold out on all their Admirals packs. I posted another source which would take much longer to ship. Tank_me has verified that they use premium Li-Ion cells. If so, the 3500 mAh rating is real for their 2S pack.
Kluosi Uav Lithium-ion Battery 7.4 V / 8.4v3.5ah 2s1p Use Single Cell Ncr18650ga Combination Suitable For Different Drones - Battery Packs - AliExpress I have one of this pack on order. I will test and report back the result. (Don't hold your breath, the shipping is going to take a long time.)

If you are electrically handy, you can build your own 2S pack using premium quality cells like I do. You do not need special equipment. But a good, high power soldering iron and a heat gun (for shrinking the wrap) are must.

My post you quoted is in response to statement that battery pack manufacturer's rating on the pack can be trusted. In my observation, it is a jungle out there.

[cmdrcody]

Kluosi Uav Lithium-ion Battery 7.4 V / 8.4v3.5ah 2s1p Use Single Cell Ncr18650ga Combination Suitable For Different Drones - Battery Packs - AliExpress I have one of this pack on order. I will test and report back the result. (Don't hold your breath, the shipping is going to take a long time.)
.

Yeah, I looked at the ETA to arrive if I ordered one - mid February 2023!

[keilau]

Yeah, I looked at the ETA to arrive if I ordered on - mid February 2023!

If you find other option, please, buy and test the battery pack. I will be very interested to know the result. If the AliExpress pack can match the MotionRC Admiral shorty pack in performance at 1/3 the cost, it may be worth the wait?

I do not understand the 2 months shipping time by the AliExpress seller. But the pack price is cheaper than I cam build DIY 2S 18650. Whatelse can I say! I ordered one of this pack due to tank_me's recommendation of this battery store. They have not shipped yet 2 weeks after I placed the order. I wonder what is tank_me's experience ordering from them?

[cmdrcody]

Well, T-90 tank arrived today. Everything good - except the battery.
Tank came with Tamiya battery connectors and the battery was flat dead! 😠
Called Motion RC customer service and explained the situation with them. I expected XT60 battery connectors as was shown in the demo videos and was very disappointed that the battery was junk because it was well below the threshold voltage limit for a Li-ion to even take a charge.
So now the good news - They are going to send a new S2 7.4V 1800mAh Li-ion battery with the XT60 connector (female) and a XT60 (male) to Tamiya (male) adaptor connector to make it right. Was hoping they just had a XT60 (male) connector battery harness that I could swap out with the Tamiya battery harness to the controller board. But I'll just do with what I got for right now. 😒
I guess I'll just take my time and start putting all the appendant parts on while I'm waiting for the stuff to come in from Motion RC. 🤕

[SoCalBobS]

I'd mentioned this in another thread, but if you're using an advanced charger, it may not recognize the low voltage level. I've had a couple HL batteries dead out of the box and put them on the USB charger for a day. They came back to life.

[keilau]

I understand that MotionRC is currently sold out on all their Admirals packs. I posted another source which would take much longer to ship. Tank_me has verified that they use premium Li-Ion cells. If so, the 3500 mAh rating is real for their 2S pack.
Kluosi Uav Lithium-ion Battery 7.4 V / 8.4v3.5ah 2s1p Use Single Cell Ncr18650ga Combination Suitable For Different Drones - Battery Packs - AliExpress I have one of this pack on order. I will test and report back the result. (Don't hold your breath, the shipping is going to take a long time.)

Yeah, I looked at the ETA to arrive if I ordered one - mid February 2023!

I received the "Kluosi Uav Lithium-ion Battery (7.4 V / 8.4v3.5ah 2s1p)" on 12/16, or 3 weeks after I ordered. It is faster than their 2 months estimate. The 3 weeks time is typical of many sellers on AliExpress. It is quite acceptable. It is wrapped in a foam sheet and shipped in a small carton box so the packaging is very good. The battery pack looks the same as the HL pack with a XT-60 power connector and the XH balance charge plug. All these sound pretty good. But the main question is whether this the 3500 mAh battery that the seller promised.

Before I accepted the package, it has been sitting in the freezing temperatures of Chicago for 3 days. When I top off the battery charge as received, I found something unusual. The iMAX B6 charger was set at 8.2 volts cutoff. The battery dropped to 8,05 immediately when I stopped the charging. Is it the cold soak effect? I proceeded to the discharge process to find out the effective battery capacity.

I set the discharge current to 0.7A to simulate the HL tank. 2.7 hours later, the discharge stop when the battery drops to 6.2 volts and the capacity reads 1799 mAh. While it is not the 3500 mAh that the seller advertised, I am not disappointed. I saw the battery sustained more than 0.7A for 2.7 hours which means it will run a HL for at least that long. It is good to see that this battery never dropped below 0.7A all the way to the end. I am convinced that this battery pack uses premium cells. At under $10 per pack, it is the best deal to run HL T-90 and T-72 bar none.

I will let the battery sits overnight at indoor temperatures. When I test again tomorrow, I expect to see more consistent numbers tomorrow. Stay tuned.

I ordered 2 of the 2S2P 18650 packs that tank_me uses with modified HL chassis. At $16 per pack, it is much cheaper than I can buy premium cells. I hope to be able to reconfigure it to my DIY HL pack for most other HL tanks. I expect that I need to do only minor surgery to the 3-wire XH balance charge plug. If successful, I will post my process here.

[tank_me]

Like I've said...I haven't done any scientific tests on them, but they have served my needs pretty well up to this point.

[keilau]

Like I've said...I haven't done any scientific tests on them, but they have served my needs pretty well up to this point.

We do not need a scientific experiment to know our battery. We all have smart charger that has enough features to simulate real world use to allow us to make the best out of what we have. The pack you referred me to uses 30C cells that allows quick charging. Starting from 6 volts, I can charge the 2S1P pack to 8.19 volt at 3A to 1700 mAh in 40 minutes before the charge current started to drop off. The discharge demonstration will take much longer at realistic HL tank usage current.

[cmdrcody]

We do not need a scientific experiment to know our battery. We all have smart charger that has enough features to simulate real world use to allow us to make the best out of what we have. The pack you referred me to uses 30C cells that allows quick charging. Starting from 6 volts, I can charge the 2S1P pack to 8.19 volt at 3A to 1700 mAh in 40 minutes before the charge current started to drop off. The discharge demonstration will take much longer at realistic HL tank usage current.

Are you using all the Li-Po settings on your smart charger since these batteries are Li-Ion 2S 7.4v 3500mAh? I know the settings on my iMax B6AC V2 only show Li-Ion batteries to show a full charge to 7.2 volts.

[keilau]

Are you using all the Li-Po settings on your smart charger since these batteries are Li-Ion 2S 7.4v 3500mAh? I know the settings on my iMax B6AC V2 only show Li-Ion batteries to show a full charge to 7.2 volts.

No! You must match the chemistry of the battery to the charger setting. I have the SkyRC iMAX B6. I had an off-brand B6 before. The programming on the off-brand B6 was all messed up. The name brand B6 may cost a little more, but is assured to be working properly.

When the charge is full on the Li-Ion pack, I switch to measure mode. The individual Li-Ion cells are 4.10 and 4.09 volts respectively.

The SkyRC iMAX B6 also has fully functional programming mode, but the off-brand does not. Setting Li-Ion pack charge to 4.10 volts per cell is a good idea to get long battery life. So far, I use the default SkyRC program for all my charging.

This is the top off picture after I received the pack.

[cmdrcody]

No! You must match the chemistry of the battery to the charger setting. I have the SkyRC iMAX B6. I had an off-brand B6 before. The programming on the off-brand B6 was all messed up. The name brand B6 may cost a little more, but is assured to be working properly.

When the charge is full on the Li-Ion pack, I switch to measure mode. The individual Li-Ion cells are 4.10 and 4.09 volts respectively.

The SkyRC iMAX B6 also has fully functional programming mode, but the off-brand does not. Setting Li-Ion pack charge to 4.10 volts per cell is a good idea to get long battery life. So far, I use the default SkyRC program for all my charging.

Are you using your SkyRC iMax B6AC V2 connected to your home PC using the 'Charge Master' program? The maximum voltage shown for the Li-Ion 2S battery is 7.2 volts and can not be raised any higher than that. Does your charger show the same? I'm new to using this charger and it is not a off-brand model. Can you provide me with all the settings for the following: Charge, Discharge, Fast Charge, Balance and Storage including current ratings for each setting that you are using to maintain and extend the life of the batteries. If you wish to send me a private message - I'm good with that.