Battery c

[Rcrmel]

If I use a battery of 15 c in place of a battery of 50c what will happen. ? Both batteries have the same voltage 22.5

[fhhuber]

This depends on what demand is placed on the battery.

Keeping the same cell count, voltage and mah capacity:

If you are demanding 5C current (drain the pack in abut 12 minutes) then you might notice little to no difference.

If you are demanding right at 15C (4 minutes to complete discharge) you will notice the lower C rated battery gets MUCH hotter and delivers a bit less time. The low C rated battery will not survive nearly as many charge/discharge cycles as the high C rated battery.

If you are trying to demand more than 30 C (2 minutes to complete discharge), the 15C rated battery might catch on fire. It certainly will not deliver as high power because the internal resistance increase due to heat will limit the current that can actually be delivered. The low C rated battery is unlikely to survive even ONE discharge at this level.

In reality, only our highest demand aircraft need 20C or higher rated batteries. There's a minor performance difference due to lower internal resistance of the higher C rated packs. Its hard to measure the difference in flight time of a 10C rated pack vs a 50C rated pack when you are demanding 5 to 8 C average current.

I generally just get the 25C rated packs because not even my highest demand aircraft are needing more than 20C at 100% throttle. You always want the C rating to be more than actual demand.
for some competition uses, you might care about the slight increase of power available by going to 50C. The average person just "sport flying" (even with EDF models) would have a hard time noticing the difference between a 25C and a 50C when flying any of the RTF EDF models when using adequate capacity packs for 3 to 3.5 minute flight times.

[rifleman_btx]

Ive always kept to the rule of stay over 30c and things will be well. Now the other factor when it comes to the c rate is the packs capacity, so let's say you have a 10,000 mah 10c pack, and a 5000mah 20c pack these both should run at max 100 amps, however I would probably only run a system that maxes out at around 85 amps with those packs. Having overhead for spiking and also just the fact that out where I live the temps reach 100 plus on some days, so heat build up has a little head start. I honestly just feel better with a nice large overhead to play with to save my packs from an early retirement.

[fhhuber]

Never bought higher than 25C.

I've flown 5000 watt 12S EDF using sets of 4 * 3S 5000 mah, average flight 3.5 min with 15% to 20% left in the packs,with the batteries surviving an average of 300 cycles with summer air temp exceeding 110 on some days. (average summer includes 40 days above 100 F in a row)
The EDF needs a new home... the plywood in the old model all delaminated from in flight stresses and humidity.

Note: I can remember when finding 20C rated packs was hard. 8C to 12C were the norm. BVM (Bob Violett Models) carried the 20C because their EDF demanded it. 25C didn't exist.

[rifleman_btx]

True, and even then your still talking about 100 amps capable, since you have 5000mah capacity. So I can totally see why yours lasted. And it would seem that had given you a nice buffer as well between the max amps you drew out compared to the 100 amp capability.

[xviper]

Post no longer needed. Spam post taken care of by mod.

[Elbee]

It is all better now. Thank you for flagging the post. Best, LB