Battery (GP3300s) failing...
 

I run 14 cells GP3300s.

I charge them to 3600mAh, as that is what they peak too with the Great Planes Triton.

Lately, the runtime and power is alot worse with my Maxx, it could be that all this weight I am adding with allu' is slowing it down but I wouldn't of thought it would make that much of a difference.

My Triton can discharge and cycle (which I have never done before).

How could I increase the performance of them again? Can someone describe the basics of how to cycle your cells?

Thanks.

Get a 20 amp discharger minimum, the triton can only do 3 which is a bit low to get the pack's up to life.

Then it's just charge, let them cool down and wait for a few hour's and then discharge. Repeat this step a few time's(like 5) and try again. No improvement? Try gearing a teeth or two down and see what happen's(actually do this before you buy new stuff).

At what amp rate do you charge your battery's?

Charge at 5A.

I sold my 15A discharger I had, as it toasted my other cells I had.

Try chargeing at 4amp. I normally charge my gp's at 4,5 and they get not really hot but hot when they peak. When doing 4 amp's they are hand warm when they peak and seem to keep a much steadier(sp?) voltage/ ampage.

Alway's keep a close eye on battery's when charging/ discharging. I'm using a team corally digital discharger which doesn't like to discharge full battery's and nearly caught fire doing so. Now it's got a cpu fan strapped to the side to keep it cool and it's fine.

The discharger you where using must be broken. 15 amp discharge isn't anywhere near fatal for gp's, or the cell's where old and worn. But still I doubt that since the amp draw in a car/ truck is much higher.

My GPs don't get warm when charging to 3600mAh?

I charge 2 packs at once and normally one (that is connected straight to the charger rather than stacked) is warmer?

Should I charge until they are warm/hot? Ignoring what the Trition reads at?

Try charging 1 pack at the time. Mayb it's false-peaking. Any pack should be warm'ish when charged full.

If there is a difference in the individual packs it could produce a false peak. Are you connecting in parallel or series. If parallel it should go to 6600mah which may go beyond the limits of the triton( I use a pirrana digital peak and it goes to 5000mah) I'm not sure about series as i don't know the limits on the charger. I hope this helps

I have it like the image attached, where the other battery is stacked (connected) to the other batteries wires.

You shouldn't have to charge at 6600mAh, as no matter how many cells you have the capacity is always 3300mAh?

I don't know how that should ever work properly. It simply can't, the charger can only detect if 1 pack is full, not 2.

Did you try charging 1 pack at a time at 4 amp's?

I use a superbrain 959 and have 7 cell gp3300 packs and when i charge them they dont get very warm, maybe a slight rise in temperature but hardly anything. When i run my emaxx with two fully charged packs i get about 5mins run time, but thats 90% full throttle in first gear doing wheelies and donuts. Is this normal runtime for my batteries? or is my charger not charging them fully?

Whenever my GP3300's peak they're around 45C temperature (my cheap packs run closer to 50C). I detailed my charging methods in a recent thread I think.

So are you plugging the batteries like, + from one and + from the other go to the charger plus, and - from both batteries go to the charger negative? Or + from one battery goes to - on the other battery, and the unused + and - go to the charger? The first method is parallel, the second is series. In your car you run series, if you charge in parallel, your charger sees it as a 8.4v 6600mah battery, which it can't fully charge.

Charging in parallel or series with packs that aren't very well matched isn't a brilliant idea anyway, although it does work it slowly destroys the batteries, as one pack will fully charge before the other, so it'll either false peak and not give you full power, or one pack will overcharge causing damage.

Basketti: Batteries are always warm to touch if fully charged, due to the charging method, if yours are barely warm its a hard one to call. Can you adjust the delta peak value on the 959?

Whew, sorry for the long reply :)

I can change the amps, and mV. whats delta peak voltage? Thanks

The delta peak voltage is what the mV is. Its the voltage drop the charger looks for, which tells it when the battery is fully charged. What mV value are you using?

im using 40mV

Whats the lowest setting you can run? I use a 28mV cutoff on my 7 cell packs, and they come off nice and warm, but not toasty. 40mV means your charger should be cramming a bit more charge in than mine, so in theory, your cells should be coming off a bit warmer than mine.

Are any of the cells hotter than the rest?

The lowest setting i can run is 5mV, my pack just peaked and i got my infra red temp gauge and the temp was 19C. I checked the cells but they are all the same temp. They have been like this since they were new, i got them about a month ago. I have four 7cell packs and none of them ever get really warm. After i play with my maxx the batteries are warm. Should i increase the mV? Thanks for the help :)

No problem :) What temperature are you charging them at? room temp? They're definately not getting a full charge in, do you adjust the mV per cell, or for the whole pack on that charger? With my setup it's 4mV/cell, you could try like 8mV/cell (so 56mV total) and see if that comes off warmer, and how the runtime is.

Another sort of test is, how long (in mins) does it take to fully charge a battery from dead at 4.5 amps? It takes my charger on average 48-52 mins at this charge rate, and that delivers a full charge from a pack thats been discharged and equalised.

Also, make sure there's no fans blowing near the battery, that messes them up. I'm off to bed, will check here in the morning :)

Yeah im charging them at room temperature (16C). I just charged 2 packs and before charging they are 16C, and after charging they are 18C. I charged them at 4.5 amps and 40mV (like i always do), it took about 35 mins to peak (each). Then i put them in my maxx and i got 5mins and 30 seconds run time. Im going full throttle about 60% of the time while my dog chases it. Should i increase the mV ?

Tomorrow i might try charging the packs twice and see how that goes.

So is MV the peak sensitivity? The lower the more sensitive? Mine is set to 3! No wonder it peaks incorrectly all the time.

Correct. Although for good cells, you should be able to run it low (on a quality charger). I run 4mV/cell all the time (except when I'm charging NiCD's, then I do 10mV/cell for reverse pulse charging). If the cells aren't warm try raising it a bit, or just put it back on charge again and let it continue until they peak warm.

Cheap chargers aren't very sensitive to this so will false peak, there are 2 ways to tell when a batteries fully charged, when it delta peaks, and when its temperature starts rising more than 1C/min. This is why they generally peak aroudn 40-50C.

Basketti, I don't understand why they're not fully charging, so like you say try putting them back on charge right after it peaks if they're not at least 30C. You are trying to charge just one 7 cell pack at a time right? Or are you hooking 2 up to the 1 output on the 959? Because that would cause this problem.

yep im charging one 7cell pack at a time. I peaked two packs twice and my run time was 9mins and i was going flat out the whole time, thats heaps better than 5 mins. the temp after peaking twice was still the same, the temp doesnt really change during charging lol. i've been waiting for the superbrain 977 to come into stock at towerhobbies since i got my emaxx lol, but it still hasnt come into stock.

Did you try raising your mv? I had a problem with this. I raised the mv up to 10mv on a ice. I guess it was per cell. It made me peak where it supposed to be at.

oh ok, i'll try that, thanks :)

can you adjust how fast it charges to? I seem to get a better charge at lower charge rate.

I normally use 4.5 amps - if I'm re-peaking batteries before a race I do it at 6 amps, but charging a battery at this rate will shorten its life no matter how well you look after it.

10mV/cell is closer to a NiCd's cut off, but will work..if I did that to my cells they'd probably overheat, but as yours aren't getting warm it may well solve your problem.

Let us know how it goes.

If you charging 3300 I like to use 3.5 amp. It is close to the 1c rating. I seem to get a better charge. Less heat to.

Back in the day of old nicd's, wasn't they charged at 3c? How times change..

There's your problem.

In my family, we've owned 6 of those, and every single one of them had problems false peaking no matter what we did with them.

Sell that thing on eBay and get a decent charger like the Duratrax Ice. It'll be worth it. ;)