Can you trickle charge AA NiMh in your radio?

[vince32837]

I was wondering if I could get away with not removing the AA NiMh cells from the futaba radio stick, and let say trickle charge them overnight for a complete charge not a top-off? I have been using throw away AA's all these years...

thanks Vince

 

[Robie6]

an overnight trickle may not bring the guys up to par. If your charger has both trickle & charge just put it on charge for the no. of cells & NiMh your using & on most chargers once charged will switch over to trickle. Trickle charge I believe is for when your not going to run for awhile but want to keep your batt. up to snuffuke: dont try to charge non-rechargable cells even a little.

 

[vince32837]

Thanks, I'm trying an experiment trickle charging them from 40% w/ 100 ma rate.

Vince

 

[olds97_lss]

I use the jr wall charger that plugs directly into the transmiter with radio shack nimh in my jr xr2 transmitter and just keep a close eye on the volts and temp of the batteries. I've been running the same 8 bat's for 2 years now. Almost every weekend gets 4 hours worth of running. Well, when it's above 30 degress outside and not raining that is.

I made my own 5 cell nimh receiver packs with the same bat's and use radio shacks 4-6volt switchable hi/standard and nicad/nimh charger. I had to make a few wireing mod's from the charger, but i've been using this in the same fashion for 2 years as well.

 

[vince32837]

olds97_lss,

That's good to hear the Radio shacks hold up! Does your XR2 radio needle get pegged to 100% or 80-90% at full charge?

So every 2-3 hours or so you pop the pack out the Tx to feel if warm? That JR wall charger can't be more than 50-60 ma must take you 20-25 hours right?

Thanks Vince

 

[Candyman]

There's no problem charging the batteries while they're in your tx. But it's my understanding that NiMH batteries shouldn't be trickle charged. I'll have to find the article I read that said that. You should be able to easily just peak them now and again to make sure they're full. NiMH batts don't have the same memory effect that NiCds have so you can do that to keep them charged. It's still a good idea to fully cycle them now and again.

And it's possible that your voltage meter may not show 100% when fully charged. Usually, the tx uses 8 1.5v alkalines which give a full voltage of 12 volts. NiMH batts are 1.2v per cell so the same 8 cells will only give approximately 10v fully charged. Thus, the discrepancy...

 

[olds97_lss]

The xr2 has a digital readout on it. And no, it doesn't take that long to charge. Initially, when i first bought the bats maybe, i don't remember. That was 2 years ago.

The bats are 1.2v 1800mAh AA's. The remote takes 8 of them, this adds up to 9.6, but the damn remote beeps at me @9 to let me know they are low. I actually overcharge them to 11 - 11.2 volts. @ 11.3-11.5 is when the start to warm, so i don't go any higher than 11.2. After i run for about 4-5 hours on a saterday, the volt readout on the remote usually says around 9.6-10. So, i charge it back up to 11.2 and it normally takes about 1-2 hours.

I've been doing this for two years with the same batteries and haven't yet lost any life out of them.

I used to pull the bottom plate off and hit the bats with an ir thermometer to see the temps, but now, after doing that for a few months, i know what voltage the bats start to warm. So i don't do it anymore. I just charge to 11.2 and unplug.

Radio Shack just started selling these:
http://www.radioshack.com/product.a...y_name=CTLG_009_011_006_000&product_id=23-532

@ 2000mAh, i may be getting a few for my receiver packs that i make.

 

[vince32837]

Thanks guys,

I will stick w/ the NiMh's AA's. I called Futaba tech support, they said the whole staff uses Nexcell AA''s(NiMh) and they abvout 1/2 of them charge their radios right in the handle at 250 mA max. The tech said Futaba jack limit is 500 mA.

Vince