Jim109

Hey all!

Does the AMPs you discharge at for Nimh batterys matter other than the time it takes to discharge the battery? Does it hurt the battery or battery performance( by making a memory of low output) if you use the low amp discharge ( 1-2A ) on most chargers? Also whats the MAX you should discharge at?

I'm trying to figure out what new charger to get and all the chargers have a very low discharge rate ( 1-2A ). Its sometimes a number of months on some batteries between use so I'd like to be able to cycle them ( discharge and then charge) to keep them in good shape. My local hobby shop employee told me never to use the discharge on the chargers however as it will put memory in the battery that is only has to output power slowly and ruin the performance on the battery. Is this true or BS?

Thanks so much for the help!!!!

Jim

Ps. Also wanted to verify... you never need to discharge or cycle LiPos correct? The discharge would be for NIMH batteries only?

nubie-wan

iTrader: (4)

There is a lot of truth to the discharge rate on NiMH batteries affecting memory. I'm not sure why they put discharge on chargers because it is generally inadequate for storage or cycling. I would use an automotive light bulb array to pull them down if you don't use a vehicle to do so. This will simulate the higher discharge rate like running an RC vehicle fairly hard. Be sure to monitor the voltage when using on LiPos.

LiPos will need to be discharged occasionally, especially if you fully charge them and don't run them or plan to for more than several days. They sit at a 3.7 V storage charge per cell. Their performance is improved by cycling new ones about 10 cycles. I wouldn't do that with a charger, but by running in a vehicle down to 3.5 - 3.7V per cell and then balance charging. Many ESCs will allow you to set the LiPo cutoff voltage yourself. Don't set it too low.

MarkA

iTrader: (21)

First, yes and yes. You should store your lipo batteries with a "storage charge" on them but you don't regularly otherwise discharge them.

NiMH batteries used to matched by discharging them at 20-30 amps. In general, higher is better with those. That being said, the performance of even the cheapest lipos out there today is so far beyond what the best NiMH packs would ever do that I hope you're asking these questions as it regards receiver packs and not the one to power the cars. In the case of receiver packs, discharge rate/storage/etc. won't really matter as much. In the case of the cars' batteries, it really is time to move on or also not really worry about how much performance you get from a NiMH pack.

nubie-wan

iTrader: (4)

Another good thing about LiPos is that they don't have to be discharged to full depletion to recharge as they don't have memory like the NiMH batts do. I like to run a couple of heats and recharge for the main. Just don't let them get too hot.

I prefer LiFe packs for receivers/transmitters anyway. Lighter and last much longer.