10S and 12S adjustable charger from China - groupbuy - Worldwide!

Exactly for 99% of the time I have all night to charge, só better to stress less the battery’s

Would be nice use this charger with a 12s1p A123 for 30 min recharge time, but the range would be too close to the distance I ride daily

I am not using a BMS with by build and now I have wired the charger in and tested it for about 25 mins I saw +2v on the battery but when I checked at the balance leads I have 8 cells at 3.7 and 2 at 3.8v.

Anything to worry about?

I dont really get what youre asking

Only really if 0.1v drift anything to be concerned about.

The battery is still charging and in the cc phase. Once you leave it in the cv stage for a while the difference will go away

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Not really, charge to 4.2 and see what the drift is there. No cell should exceed 4.25 ever. If your cells are drifting it might be because you have bad weld/soldering too much.

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Not really how that works. There is no balance board. the drift is due to internal resistance differences, over time it will drift further and further. The reasons behind lots drifting are bad cells, bad welding/soldering, discharging too low, charging too high. Even the best cells will drift over time, having a charger that does cv charging will not remedy this ever unless you balance.

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At 0.1V we are not talking about true drift though are we? It is just a slight charge difference that will go away once the pack is fully charged.

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OK thanks. Wondered if that would be the case. Will see how we fair after a few cycles. Still want to keep the bms out of my build but might figure a way of balancing occasionally if drifting starts to appear.

Maybe? Not really sure, that’s why I asked for him to measure them fully charged. @Norco, still charge to your full levels and make sure you are not exceeding any limits.

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OK will do. Still working on my diy motor mount so will hang fire until I have a way to discharge the battery so they aren’t sat fully charged.

Ok so I charged and all of the parallel packs have balanced out with each other except one.

Now I have 1 at 4.10v and the others at 4.06v-4.07v

This gap seems to be widening. I am guessing its times to open up the pack and take a look but I would have thought that if I had a dodgy connection then the voltage would have been lower after charging? Any ideas how I could manually bring this voltage down to the same as the others then try to discharge and recharge?

I still want to avoid an onboard BMS if possible. I have an imax B6 to use if this could be of help? I had thought of splitting the pack so that occasionally I could balance charge the 2 halves?

Any advice /opinions would be really appreciated @PXSS / @Maxid ?

Charging as two halves is a good idea and the reason why I have two 5S balance leads on my 10S pack.

What voltage did you charge your pack to and how long did you leave it connected? Keep in mind that the CV phase will take some time as the current drops.

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There is a bad weld in that group. That would be my guess. The reason the voltage is higher is that the one cell has less capacity and therefore it charges faster than the others. When discharging, it’ll be the opposite. Lower capacity means it’ll discharge faster than the others so your voltage on the low end will be lower than the rest.

I recommend getting a BMS. If you don’t want one then use a hobby charger to balance. When discharging there is nothing to protect your cells from going out of balance and having one go below 2.5V. That is the advantage of having a BMS. If that were to happen then the BMS would cut power and protect your battery whereas now, if that happened it would cause damage to your battery

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Ok thanks both. I’m going to keep my eye out. Ill have a look at that group and see if I can find the bad weld. Once that is fixed is there anything I can do to bring that group down to match the others? eg wire something in to just that group? Also I am assuming that the pack would need to be split into 2 5s packs while balancing using an iMax B6 as this will only balance up to 6 or 8s I think.

Is there worth in waiting to fix it until I have discharged the battery as a whole (but only partially?)

What you could try is splitting the battery and doing a discharge test on your B6. Both packs should have similar capacity you can get out. If not then you know that the one cell should be replaced/reworked.

Just balance charge again to 4.1V per cell with your B6 - the charger will take care of the rest

Sounds like a plan. 5s plugs ordered and i’ll open it up tonight. Such a pain as it had come together so nicely.

Can I get Contact info for the supplier of the power adapter mentioned in the group buy? Nevermind, I actually found it thanks to @OskarCastrone post. Thanks dude. :+1: