Battery Balancing issues
 

Have a fairly new protek 4900 shorty 2s, on my icharger the battery takes 30 minutes to discharge balance and 30 minutes to charge balance. IR less than 2 on both cells, but one cell takes a very long time to balance. One cell we be at 3.4v quickly and 4.2v on the charge, the other cell will still be at 3.6 and 4.0 respectively.

Any ideas or tricks to kick this pack back into shape? Battery has no puffing.

I think that means one of the cells is a little funky if it only happens with the Protek shorty. If they keep discharging to uneven voltages I would contact Protek/Amain and see if they can help you out. I've seen certain packs over time take a while to balance though they usually always discharge at an even rate.

I'm pretty sure there is a "quick balance" mode on the iCharger, try that maybe

What are you charging/discharging at?

30 discharge 40 charge.

i lost faith in protek a few years back went thru same issue with my charger that i could adjust balance charge to 5 amps. Schulze 1450. you could make a single cell plug to do a direct charge as 1 cell to each cell but that will still take longer might do it in under 20 minutes..use a servo extension and your main plug ..

Try charging at a lower amperage and see if that is any better. BTW how big is your power supply?

If youre trying to get the heat in the pack before each run you could try discharging then charging right away so it just finishes before you tech. I had one cell in my protek pack that was doing the same and coming up lot higher on IR's compared to the other in the pack. I put it through 3 cycle runs in the same night at home and brought it back to normal, been good ever since but I only charge at 16amps.

So what am I missing here, the OP said he charges at 30 amps and discharges at 30 amps, then says charging at 40, now I only charge at 10 amps and takes roughly 18 minutes to charge my battery, not that I have timed it, but I have it fully charged just before hitting the track, now logic tells me if I was charging at a higher rate, the battery should be done sooner, as I can even charge a 4s in 22 minutes at 10 amps (balance charge - fast balance) so what am I missing?
My charger is a icharger 308 & 406 and I start charging my batteries 3 heats before I am up.

Only said I charge at 40 amps, not sure what you misread. The battery is taking an exceptionally long time to balance, because one cell is lagging behind in the balance process. Your charger may not provide you this type of info.

Regarding time, my other batteries charge in less than 10 minutes at 40 amps, and that’s from a completely drained state after discharging at 30 amps. If I charge a partially charged battery without discharging, it’s 5 mins or less.

So then it's the battery itself taking forever, compared to your other packs, as I was heading down the road on your charger being the biggest problem, but if your pushing the high amp charge rates, what do you expect from the battery as if it was mine it would be gone, I don't want the fire screwing with a temperamental battery pack

so ur charging a 8.18 c LOL enjoy the fire..a 40 amp charge

Just contact customer service they’ll take care of it.

Keep your ignorance to yourself. Thanks.

Please dont do this, if one cell is at 4.2 and one is at 4.0 it will continune to charge normally. When one cell is out of range always charge with balance and accept that is how this battery is.

Bro, you have balls of steel.

Charging at 40 amps, I aspire to levels of greatness such as this. I'm also not being sarcastic.

You may want to tone it down a little bit with this pack and maybe do 20 amps?

Hundreds if not thousands of people who run at the top level at their respective tracks in 17.5 and 13.5 charge and discharge at these astronomical levels. I agree, it sounds insane and dangerous, but 30+ guys at my track alone do this every race day and have been for many years without issue. A level of care and attention to the condition of the battery as well as a charger capable of monitoring and charging at these rates is necessary. I wasn’t a believer until I stepped up from 20 amps to 40 and started discharging. They also discharge at 40 but I’ve found 30 still gets the IR’s down for a punch that doesn’t fade for an entire race.

When this happens, I use a stand alone balancer to get both cells to the same level, let the pack sit for a while, then measure the resistance using an esr meter to determine if one cell is weaker than the other. Measuring ir while charging isn't necessarily accurate.

Regarding this particular battery, I’m going to run it through a few different cycles and tests before disposing of it.

I've had 3 protek batteries that do the same thing. I've also had 2 that were just fine. Doesn't matter what your charge rate is the battery is just junk. Cycling 20 times and it won't fix it. I contacted Amain for one of my batteries that had the issue, and they replaced it after I sent them a picture of it on my icharger. However, I just dealt with the fact that the other two are for practice. I now run R1 batteries. I've also heard good things about the EAM batteries.

Not a bad idea. The issue isn’t IR though (which is 1.6 and 1.8 on this pack), the issue is simply the time it takes for one of the cells to match the other.

Are you an on road guy? I’ve also heard great things from the local guys who run their products. My next battery will be an R1.

Honestly man, your going to be at the limit of what a pack can do when charging at these rates. You may have gotten a cell that passed QC at 10 amps but over 30 amps its just not built right to handle it.

Your kinda on the cutting edge of charging and while alot of people may swoon over protek, its Amains off brand. Maybe the dude assembling the cells had a cold that day and messed up. There is no way to know these things.

They're doing it on healthy packs that don't have balance issues. You're playing with fire doing it with a suspect pack.

is it wise to charge a 2 cell lipo at 30 to 40 amps..hmm to me no.. why push a battery to those extremes?.. from the times you listed in charge time your no faster than me charging at 1C only in 15minutes i can charge my battery from 7.70 volts to 8.4. then back on the track no risk of fires to anyone. marshalls drivers around your charge anyone..

Yeah, I race onroad at ASR.

I don't use this "quick balance" feature at all, but I thought it was in there, I didn't know that's how it worked, good info

40A is by no way "astronomical"
I discharge @ 30A and charge at 15A if anyone cares
30A = 215W so, like a 13.5?
The first generations of lithiums were a new frontier in batteries, maybe scared us into worrying too much of a fire, now I always charge in a lipo bag and won't walk away from a charging battery that i'm trying to get warm, but that's just basic responsibility, I have little belief that my batteries will actually burst into fire from what we're doing, especially if you're on the LiHV or whatever packs where we're only charging to 8.4 and they can supposedly take 8.6

Its also against all know leagues rules and sanctions events...your a danger to others so carry on..:flaming::flaming::flaming:

Lol.

It's possible that it's not discharging through the balance lead. I had this happen a couple of times with my 308duo when it was taking a long time to charge/discharge. Progressive eventually sent me a different charger. I would try a different charger. It does sound to me like it's possible the battery might not be optimal too.

No other issues with other packs, fortunately.

My 2 cents. Charge at rates over 10 amp, and probably forget any warranty. Any issues with balance / bad Resistance, I would not push that battery any more. Charge at 10 amp and use for practice. Just a price to pay for pushing the limits. If anything, I would at least charge / discharge in a lipo bag, anything over 10 amp.

Gotta love RCTECH, start a thread to ask a question and get responses about everything except the question.

I don’t need advice on what everyone thinks other people should charge at or about properly handling batteries. Thanks anyway.

You asked what you needed to do to this battery to get it in shape. "Stop abusing it at such high charge rates" while it's in this state is a perfectly valid response.

+1 well put giga.. abusing totally agree..

op you where given what to do's in posts 2-8 you chose not to agree or follow any advice that would make sense to people who charge less than 8C..

Have you measured the voltages of the individual cells after discharge? Could be you're over discharging the one cell and that's why it's way off.

I don't think the iCharger measures individual cell voltages when discharging. Would be a nice feature and one that I use in my own Arduino based discharger. I monitor both cells and when either one of them gets to the cutoff voltage it stops. I think the iCharger like most other chargers when you say 3.5v/cell, just multiples this number by the number of cells and cuts off when the pack voltage reaches that number.

The 406duo has an option to balance as it discharges. Also, the fast balance setting on an iCharger doesn't hurt anything.

As for everyone that says high current discharging and charging is bad for the battery you are flat out wrong. I got an entire year out of my last battery doing 11C discharging and 10C charging. I know people keep batteries longer than that, but in terms of pure performance after a year a battery is done. If you don't push a battery, you don't really notice the drop in performance as they pass the year mark.

The chemicals in a battery can do a certain number of cycles before they lose capacity, and increase internal resistance. When you push batteries hard you need to pay close attention to what the cells are doing. The numbers don't lie.

The batteries in question are rated for up to 10C charge rate, however the manufacturer does recommend 1C to increase the lifespan. Though you should only use the higher rates if the pack is healthy. This one is suspect.