# Charging High Cell-count LiPo batteries

I have a question about charging and balancing a 10-12 cell LIPO battery. I have been searching around for an all in one solution chip but come up empty. I have also found out that there are almost no lipo charger chips that do more then 6 cells. So my question is this.

How do lipo chargers like this do their balance charges. Do they use a lipo charger and lipo balancer chip in conjunction with each other? If so would a balancer like this and a charger like this work?

My next question is why are there no high cell count chargers? The way I currently charge the battery is by splitting it into two 5-cells then charging each seperately which works fine but doesn't seem like the best way to do it. I guess I could use 2 balancers and 2 chargers to charge the battery simultaneously.

• This question refers to the measuring of battery stacks: electronics.stackexchange.com/questions/106970/… I imagine balancing them could either be done by having two mosfets at each cell to allow them to be in parallel or series. – horta May 31 '14 at 3:42
• If you need more energy storage, you can use larger cells rather than more of them. That way you don't wind up with large series or parallel cell counts. – Matt B. Jul 30 '14 at 17:25
• Did you find a better solution? – Russell McMahon Sep 22 '16 at 9:33
• @RussellMcMahon No I didn't. I ended up just dual charging the battery as 2 5cell packs. – Axis Sep 22 '16 at 18:15

There are very expensive $250-$300 chargers that do higher than 6s, probably closer to 10s, but not a lot to choose from and right now my memory is drawing a blank on their names, but they do exist.

I have no idea why there are not more, but I suspect that the demand is simply not there yet. Lithum batteries at those higher voltages are not as common and can be very expensive as are they chargers.

The charger you link to balances its battery by having a charging connection and balancing connection at the same time. The charging connection is directly connected to the + and - of the battery and supplies the main charge. The other connections are more complicated and, for example, in a 6s battery there would be 7 connections, one at the "-", on at the "+", and a connection or wire coming from every single cell connection. So each time another cell is added to make it a 2s or 3s, a wire comes out between the "+" and "-" of each cell added. So a connection between all 6 cells and one at the botom or "-" and one at the top or "+" and you have 7 wires coming out that will then plug into the side of the charger.

The charger then monitors each individual cell's voltage as it is charging the battery as a whole, but most chargers don't seem to start balancing until the battery is essentially full, or at least one cell is at 4.2 volts. Then it uses the seven wire connection to balance the battery, usually by discharging the higher voltage cells a little via a small current, and then charging the whole battery again slowly. Then repeat until all balanced.

It looks like what you linked to would work, except that they are for smaller number of cells in series than what you want to do.

Another option that would work for you is to do what you are doing - split the 10s into 2 5s and charge them independently, but parallel charge them using a parallel charging board and then you could charge them at the same time.

Looks like this thread is a bit old and perhaps you have found the charger you were looking for... Some chargers that fit your bill closer are made by iCharger. The biggest, baddest one they sell is the iCharger 4010 DUO. It will charge at 2000 watts total and charge 1-10 cell Li-ion/poly/LiFePO4 and all the other battery types as well. http://www.icharger.co.nz/Products/4010-Duo.aspx Hope that helps!

• Shopping answers are discouraged. Can you answer any of the detail in the question, e.g. how does this balance charge across a large number of cells? – David Oct 21 '14 at 16:17

Linear Technology makes a chip that makes cell balancing fairly easy. It requires a few external components, including a small transformer to build one stage. You need one stage per cell in the series string. Look at LT8584 - 2.5A Monolithic Active Cell Balancer with Telemetry Interface and LTC3300-1 - High Efficiency Bidirectional Multicell Battery Balancer.

I quite like the LTC3300.