Initial Cell Balancing

It will balance, but its going to take a while because you installed unbalanced cells in a pack.

ALWAYS equalize before you install.

What I would do?
Get a single cell charger and individually charge them.


oh, and BTW, thats normal. The boards heat up, they reach HLim and the BMS cuts the charger off, rests, then when the cell settles below its HLim, it will start charging again.

I made the same mistake with my pack of 24 TS 160AH batteries this week.

So, can I charge individual cells while they're in series or do I have to take the pack apart? I will order a couple of these chargers if they will work. http://www.batteryspace.com/smartch...k1cellstandardfemaletamiyaplug38vcut-off.aspx

Or this one? http://www.batteryspace.com/Smart-C...cells-LiFePO4-Battery-Pack-100-240VAC-CE.aspx

There's about three days of labor spent assembling the pack and BMS. As much time as I have spent reading here, I can't believe I missed this! There no substitute for hands-on experience I guess.

frodus said:

It will balance, but its going to take a while because you installed unbalanced cells in a pack.

ALWAYS equalize before you install.

What I would do?
Get a single cell charger and individually charge them.


oh, and BTW, thats normal. The boards heat up, they reach HLim and the BMS cuts the charger off, rests, then when the cell settles below its HLim, it will start charging again.

Click to expand...

just disconnect the pack from the main charger (the series charger) and you can individually charge each cell without taking anything apart. If you're using two chargers, just make sure they're isolated (switching) chargers (both of those apear to be).

Get the 6A version, it'l speed things up a bit if you ever have to use them again.

frodus said:

just disconnect the pack from the main charger (the series charger) and you can individually charge each cell without taking anything apart. If you're using two chargers, just make sure they're isolated (switching) chargers (both of those apear to be).

Get the 6A version, it'l speed things up a bit if you ever have to use them again.

Click to expand...

Thanks Travis,

I've seen two LA packs with chargers for each cell, but wanted to ask just to be sure.

It should be fine unless the chargers aren't isolated. Most are, so you should be fine. Better to ask now.

frodus said:

It should be fine unless the chargers aren't isolated. Most are, so you should be fine. Better to ask now.

Click to expand...

I contacted their tech support and the chargers I linked to above are NOT isolated.

nogas,

I'm sorry for hijacking your thread. I hope you're finding answers to your questions.

T

Why not just parallell them for a while? Voltage should be equal on all cells then. Notice that you MUST disconnect the series connection first!

jockepocke said:

Why not just parallell them for a while? Voltage should be equal on all cells then. Notice that you MUST disconnect the series connection first!

Click to expand...

Well for one its a PITA since he's already installed the pack.....

its much easier to put a single cell charger on each one for a little while and do it that way.



As far as isolated chargers, you really only need one if you're using multiple chargers at the same time.

frodus said:

Well for one its a PITA since he's already installed the pack.....

its much easier to put a single cell charger on each one for a little while and do it that way.



As far as isolated chargers, you really only need one if you're using multiple chargers at the same time.

Click to expand...

Ok, that is true (but still for free).

Could someone explain why switching chargers are necessary?

because switching chargers are isolated by their design.

There is no connection between AC and DC, its all isolated by transformers. The problem with non-isolated supplies, is when you connect two to the AC side, and then try to connect them to two different batteries in a series string, it causes a short because they share a negative connection.

If you're only using one charger its just fine.