nimh care and charge?

[zigzag1a]

I've been charging my batts before leaving for the races, once there I recharge a batt so that it'll have a hot charge on it. Is this damaging my batts?
Another question, when charging what should the final voltage be? On a discharged batt, before charging I'm getting a voltage of 8.3-8.5 volts. afyer charge I'm getting anywhere between 9.4-10.6 volts, why such a huge difference in voltage? these batteries were all bought at the same time.
One more question, whats the best nimh to buy, so far I have a traxxas batt and 3 venom batts, all 8.4 volt 3000mah, So far the traxxas batt seems to hold the higher voltage and runs a bit longer.

 

[zigzag1a]

nobody knows? really?

 

[slowngreen]

Charging them fast like that isnt gonna be as good for them as a slow trickle but as long as they dont get too hot, your probably ok. I'm not sure what to tell you about the voltage difference, I know nothing about nimh, so I'm no help there.

 

[jonpfive]

My personal experience is that Venom batteries are not worth the money. I had some for my little brother and we got significantly less cycles than with the DuraTrax 3800s we use for spec racing.

Lower charge rates are easier on the packs; they say that optimum for a 3800 is 3.8 amps, 4500 is 4.5 amps, etc. That said, when we race we charge at 6 amps, let them cool, and then re-peak them at 10 amps just before the race. This is brutally hard on the batteries, but we are just now having to replace them after racing them consistently for for about a year and a half. For the price ($30-40), I am happy with the performance of the DuraTrax packs. You get better performance from matched packs, but most spec classes do not allow them.

 

[tamiya]

I've been charging my batts before leaving for the races, once there I recharge a batt so that it'll have a hot charge on it. Is this damaging my batts?
Another question, when charging what should the final voltage be? On a discharged batt, before charging I'm getting a voltage of 8.3-8.5 volts. afyer charge I'm getting anywhere between 9.4-10.6 volts, why such a huge difference in voltage? these batteries were all bought at the same time.
One more question, whats the best nimh to buy, so far I have a traxxas batt and 3 venom batts, all 8.4 volt 3000mah, So far the traxxas batt seems to hold the higher voltage and runs a bit longer.

higher end V usually means they're older or more tired

if you repeatedly discharge them to under 0.9V per cell, the end V also rises
and they'll hold less capacity than when new

Generally not a fan of any Venom batts... i wouldn't pay my own ca$h for them

And as a rule of thumb, any NiMH of 3000mAh or less aren't really good grade
they're factory seconds in packs built to a price. Cells of 4000+ usually give
better current & lower internal resistance.

 

[the_juice101]

are there any specific matched packs you suggest?

 

[tamiya]

good question, i don't know who matches NiMH anymore!!

just popped over to our local powerpusher/cellmatcher/gofastagent who used to
buy 1000s of cells then cycle, measure & match packs and he doesn't do anymore
All his customers have gone LiPO it seems.

last time he did any... Intellects were the main "bigname" but they didn't last very long,
10-15 cycles and they're toast; mod boys would flog them off to the noobies.
EastPower cells were pretty good too, not top voltage but lasted a bit longer.

 

[healthyfatboy]

Check out promatchracing.com. They will match packs for you.

Oh, about the voltages. Nominal, your pack will be around 8.4V and that is where it should be. Once charged, they will definitely be higher (up to around 10.6V) but that is normal and nothing to worry about.