Faulty Trakpower?

[Mike.L]

Hey everyone, (if this is in the wrong thread please move it) I bought my trakpower not to long ago to finish my 2wd buggy, chraged it up for the first time before running it was fine,

after driving it down I wasnt too sure that my lvc kicked in. Im using a 2007spec Lrp sphere esc. Now when i read the mode for lipo programming it said that profile one was for nimh and lipos?

so i left it at that,

After i ran i down i unpluged it when i thought the lvc kicked in, so when i went to go and charge it for the second time, something was oddly strange.

When i started to charge it, with my duratrax ice(and Maxamps method balancer) Using the proper harness, the Voltage read at 6.4V OK sounds fine but as it charged the voltage was increasing fairly quickly, before it hit 3.9AMP i was at 8.4V already at CC-CV mode(all happened in about 20 seconds) So it started to maintain the 8.4V and the amperage never reached 4.9Amps(1c). Now im stumbled becuase it starts to deacrese in amperage.

I gave it to around half to 75% charge (wich took a while) and drove it again. This time the lvc kicked in but, when i pluged it in it was at 5.998V! not good....
(or might be fine)?
Now im confused and a little peeved... ANY ANY information, or diagnoses of what the problem may be..

[Mike.L]

Nothing?

[lincpimp]

So you ran the battery to the lvc and when you plugged it in it was at 6v. That is fine. You may want to leave the battery to sit for a few mins after you run it to let the voltage come up a little before you charge it. And if it is warm let it cool before charging.

Just make sure your lvc is set. Sounds like it is a 3v per cell setting.

[himalaya]

The part that I am worrying about is the voltage increased so fast during charge, that clue suggests your pack's IR may as large as hundreds of miliOhms, which I experienced only with very cheap low rating low cap cells(2~3C, none RC-type, like the one insde your ipod).

[Patrick]

Originally Posted by himalaya

The part that I am worrying about is the voltage increased so fast during charge, that clue suggests your pack's IR may as large as hundreds of miliOhms, which I experienced only with very cheap low rating low cap cells(2~3C, none RC-type, like the one insde your ipod).

Yeah that's what I was wondering as well. The higher the resistance the more voltage you need to push a certain current, and since you can't let your voltage go higher than 4.2v per cell, it limits the current you can charge at. So if you can't charge at at 1C then there's too much resistance somewhere.
I'd check your bullet plugs aren't loose when plugged into the pack, because those things loosen up sometimes and that could possibly cause some extra resistance that's only noticeable at higher amps. If you can't find anything like that, then it could be high IR like himalaya said, and it could be a faulty pack.

[Metallover]

Doesn't trakpower use enerland cells?

[Mike.L]

thats why im so confused?! However it does charge to full capacity, just take 2x longer because the amperage goes down.

I could videotape the charge next time if anyone would like?

[Mike.L]

Im using the trakpower method balancer, with one black balancing lead to the negative output lead, and the other black balancer lead with the 2mm banna plug. the third red balancing wire is to the red output lead. So i doubt there is any resistance in the balancer.

I wonder if this has any signifigance, but after driving the battery to cutoff, the temps of the esc is luke warm, motor is hot, (but you can hold your finger to it), and Surpriseingly, the banana plugs that connect the batt to the esc, They were quite hot!

Could be a poor soldering job inside the case?

[Patrick]

Check how tight the banana plugs fit in the battery, from the esc and from the balancer. Those things always loosen up. Two guys I race with have melted the case of the pack just around the plug (packs still work fine though), because of the plugs getting lose, and it happened to someone else on here a few weeks ago. I haven't had that problem with mine, but I do have the bend the springs back out on the balance leads, because they sometimes loose contact and stop the charge, even though everything's still plugged in. Haven't had it cause a slow charge like yours though, just stops altogether.

[Mike.L]

I know that for a fact that the connectors are nice and snugg because they take some effort to put them in and take them out.

But if we set aside the connectors do you think that the soldering inside the case is poor? Like i wouldn't mind opening it and doing a proper job. Its better then waiting for something to fail(if there really is some serious resistance) Its better then a 100+$ loss.

[himalaya]

Have your tried to charge without the external balancer? or charge your pack on other chargers with built-in balancer? I've experienced some older charger may cause this problem.

for e.g. the Robbe Infinity3 or MegaPower 960SR, same things with diff logo. The charger reads its inside voltage for pack volts, that value will include everything like the batt, the wires, plugs, and most significantly, the EXTERNAL balancer(internal MOSFETs, PCB traces, lead wire, plug, etc.).

The Robbe Infinity3 takes twice longer time to charge a same pack than my Hyperion 0720i under same charge current setting. Because of the sum up resistances, which the charges sees all as battery resistance, it enters the CV mode too much earlier and wastes a LOT of time there.--- though it's more expensive than my 0720.

[lincpimp]

I have had 1 issue with the trakpower packs during charge, the wire that the smaller bullet plugs into, the 2mm connector, got very warm inside the case and melted the insulation on the wire. Lots of smoke but no real damage, I just replaced the wire.

I sold all of those packs, but if I had kept them I would have just replaced the plugs with some 12 gauge wire and a deans plg, and put a rear balancer harness on as well.

[Mike.L]

Originally Posted by himalaya

Have your tried to charge without the external balancer? or charge your pack on other chargers with built-in balancer? I've experienced some older charger may cause this problem.

for e.g. the Robbe Infinity3 or MegaPower 960SR, same things with diff logo. The charger reads its inside voltage for pack volts, that value will include everything like the batt, the wires, plugs, and most significantly, the EXTERNAL balancer(internal MOSFETs, PCB traces, lead wire, plug, etc.).

The Robbe Infinity3 takes twice longer time to charge a same pack than my Hyperion 0720i under same charge current setting. Because of the sum up resistances, which the charges sees all as battery resistance, it enters the CV mode too much earlier and wastes a LOT of time there.--- though it's more expensive than my 0720.

Yes i tried to straight charge it, (Still no difference, i use aligator clips)
I also tried using a different charger and no difference.

[Mike.L]

Originally Posted by lincpimp

I have had 1 issue with the trakpower packs during charge, the wire that the smaller bullet plugs into, the 2mm connector, got very warm inside the case and melted the insulation on the wire. Lots of smoke but no real damage, I just replaced the wire.

I sold all of those packs, but if I had kept them I would have just replaced the plugs with some 12 gauge wire and a deans plg, and put a rear balancer harness on as well.

I went out for a drive on pavment and i had alot of shut downs, Not due to heat but due to the connections. I think that the banna plugs are crap. I bypassed the switch so every time im take it out and plug back in it turn on again.

What should i do with the conectors?
And does anyone think i should explore the inside of the case to see if anything is barley soldered?

[himalaya]

Read each cell's individual voltage when charging, if the problem is due to a bad solder joint, you should read a high voltage(charger limits it to 4.2V by lowering the charging current) on one of the two cells, and the other remains normal. No possibility that the two output solder joints get weak at same time.

If both voltages read similar, I am afaid either you got a faulty pack or the Enerland cells inside gone bad with a significant rise in IR.