old nicads

[badhoopty]

i tried to plug a battery directly into the wall plug when i was a kid.

at least i was smart enough to hide behind something when i did it...

lol, i'm scared to have kids.

i just got into lipo. lipo is THE stuff.

[Mr. ED]

i charged them up and as to be expected they didnt have much power and run time was rediculasly low.but i charged them up 2 more times and they seem to be improving a little.
some of the reason why i was a little nervous is because a few of the packs wires became unsoldered in the past so they were resoldered to the tabs.i'm not so shure of my soldering skills from over 15 years ago,so i wasnt shure if i damaged the vents by overheating the tabs.
i found another pack in a nikko vehicle i found in the trash yesterday.
it's only 1200mah but it was free so i cant complain.

I hope you didn't leave that nikko in the trash!
put up some pics will you?
I remember when I just started they had these kind-off grasshopper clones with a cool looking body (bison something?). But I also learned on the web they had better cars at times: to compete with tamiya etc ...

[acerpower1]

i still have the nikko but, theres nothing special about it.it's 1/10 scale "monster"truck. the esc and rx are is a one unit pc board, so i wouldnt compair it to anything "hobby"grade.it's also missing the tx and it looks like it might of been some kids sand box toy at one point.i dont think it would run anymore but,i'll post a pic when i get a chance anyway.
the pack is a radio shack pack and works pretty well at least.

[Mr. ED]

i still have the nikko but, theres nothing special about it.it's 1/10 scale "monster"truck. the esc and rx are is a one unit pc board, so i wouldnt compair it to anything "hobby"grade.it's also missing the tx and it looks like it might of been some kids sand box toy at one point.i dont think it would run anymore but,i'll post a pic when i get a chance anyway.
the pack is a radio shack pack and works pretty well at least.

old and battered, definitely not vintage , LOL , never mind the pictures

[Tadracket]

Let me run this by you guys/girls. First I take ice and bag it in a zip lock. Then I lay the battery on top of the bag and fold it over so it covers the entire battery.

This past weekend, I charged 3 650Ma NiMh batteries at 3 amps. They were good to go in under 15 minutes and the cells barely got warm.

I am currently working on a fan cooled battery box made from an old aluminum cable amplifier. I have a phase change system for my PC that hits -30C. I wonder if I can freeze the cells and charge them at 5 amps without damaging anything?

At any rate, does anyone else cool their batteries while charging?

[Eau Rouge]

At any rate, does anyone else cool their batteries while charging?

No, NiMh and IIRC, NiCd batteries LIKE heat and work better when warm. Battery heatsinks are something you never see for a reason. You don't want them to get TOO hot, as in overheating or melting, but some heat is necessary and important.

Don't put a fan on them, don't cool them with ice, don't store them in the freezer... charge them at the proper amp rating for the cell and don't stray too far when they are charging. They get heat in them when they charge and heat in them when they discharge. There are chemical reactions taking place in both, and energy is being created and released. Newer batteries like heat in them.



As for exploding cells, it does happen, and quite often. Many of the newer NiMh 4200 cells seem to go off more than I'd like to hear about, and they can damage everything around them when they go. There are photos floating around of a single cell halfway embedded into a wall.




For old cells, I would charge them at a low amp rate to make sure they held a charge, then discharge them at 20-30 amps. Then charge them up again, and you should be ok to use them if you have to. Then again, you can buy new GP3300 packs for $25 at Radio Shack that are really good packs, so there isn't much need to use a 1200mah cell in anything anymore.

[Tadracket]

Don't put a fan on them, don't cool them with ice, don't store them in the freezer...

With the ice on them, my chopper packs get a little warm. I would gestimate 105-110 F. And I get a really fast charge. Too much?

What about these 15 minute quick chargers? I have almost smoked batteries with one before.

Wouldn't it be better to be slightly warm and quick charge rather than quick charge a pack without cooling and be on the edge of melting the shrink?

[Eau Rouge]

Honestly, I couldn't tell you by temperature or time, because the best way to charge is with specific amps until peak voltage is achieved and just starts to drop off.

I would fear that a 15-minute charger is pounding the pack with high amps and not giving a complete charge to any pack.



Donno. It's tough to say either way. I haven't used a timer charger since 1984.

[Tadracket]

I bought a Titan last year for my planes and I have a mixed relationship with it. When I charged the NiMhs, I pumped 3 amps in them and the litter bugger never let up. But sometimes, I will pop a Nicd on and set it at 2 amps and the charger will throttle up and down with the amps. I would think if I set it on 2 amps (not auto) it would push 2 amps period. Maybe it is me, I don't know. It does my Lipo pack the same way but that pack was built by me so that could be the problem there

[acerpower1]

i was wondering if my old charger for nicad would work on nimh packs,and what was the highest rate i could saftly charge a nimh pack at?
i eventually will get a new digi-peak charger, but i was wondering if i could use the old one for now.

[Tadracket]

I would not use a nicad cheger on NiMh batteries. The Nickels will not like that and may speak up, very loudly.

[Mr. ED]

I would not use a nicad cheger on NiMh batteries. The Nickels will not like that and may speak up, very loudly.

You got it twisted around:
Don't use a NiMh charger on NiCad's.
They are not so sensitive and may miss the peak with the NiCads; causing overcharge.

I just got a new charger that can do both, and the instructions explain nicely what both modes do ,and why you should use which mode for which batteries.
It's actually a bit more complicated than just Nicads or NiMh.
The advised charge mode for the Nimh's depends on their capacity.