PINNED - Lithium battery conversion/info

[robert97]

SAFETY CODE 17 : Cells No Add Up

for me, blown inline fuse

[shirley_hkg]

Then the pack is WAY out of balance. Why?
So it can only charge at the same rate that the 1000mA balance circuit can drain the 3.6V cell. So you have a problem. And may need to restart after 16 hours if its not already done. The full cell wont much like being full for long periods. So you can speed things up by connecting say an automotive headlamp bulb across the 3.6V cell for a few minites. Watch on screen. Its voltage will fall, and the charger amps will increase.

Better send him a single cell preset , otherwise all the other 7 cells will be kept charging at high voltage for prolonged period . BAD !

[Furio]

Hi BM,

After disconnecting and connecting the battery, the charger worked normal. But the voltage is all over the place.I am attaching the charge graphs of today and one of 20 Dec 2018.The internal resistance of 3 cells are way out and are getting worse.

Furio

[Furio]

Dec 20 charge graf (Internal Resistance)

[Burgerman]

You have a bad connection. One of your cells or more is not making contact properly.
Bolts, oxidation, connectors? No crimps hopefully because that will do it...

Most likely crimps or loose bolts.

[terry2]

I have put Kapton and heat shrink around the cells.

Does this picture look right for the connectors? Also which cells do I connect the balance wires to?
I know the red is for live and the black is for earth. But where do the other 7 go?

[Burgerman]

That will work.

But its easier if making your own ring terminal + wire connections (as you should) to turn all the cells the same way around. You still connect the same terminals, plus to minus repeated, but now the connections are longer and easy to make.


Where do the 9 balance wires go?

Starting at your black negative battery terminal, thats the first neg wire. So 0. Then the same battery plus. And every battery plus as you go along.

[Burgerman]

I numbered them on your image.

Your nine wires. Are in fact 0 neg wire start, then every plus terminal is cell 1, 2, 3, etc.

The neg or 0 wire goes where shown as 0
Every other + cell terminal then follows on as marked. So...
1 is the first cell.
5 is cell 5.
8 is cell 8 etc - i missed some out.

Dont get it wrong because you COULD smoke the PL8.
Its hard to do that he says . Because the sides of the white PL8 balance lead is marked with red and black.

[terry2]

I numbered them on your image.

Your nine wires. Are in fact 0 neg wire start, then every plus terminal is cell 1, 2, 3, etc.

The neg or 0 wire goes where shown as 0
Every other + cell terminal then follows on as marked. So...
1 is the first cell.
5 is cell 5.
8 is cell 8 etc - i missed some out.

Dont get it wrong because you COULD smoke the PL8.
Its hard to do that he says . Because the sides of the white PL8 balance lead is marked with red and black.

Thank you so much.

Yes I am making my own connectors using 10 SQMM wire.
And the cells will only fit that way. So not much choice in that matter.

Well if my PL8 smokes, I can blame you

[Burgerman]

https://scriptasylum.com/rc_speed/lipo.html
For you to learn.

And you misunerstand. Put cells in same shape, but turn every other one 180 degrees. It means the cell connections are easier.

[Burgerman]

4S for 12v
8s is just longer...

[terry2]

U just tried to charge my pack.
And the PL8 goes off and on the power supply it says OCP.

Please tell me it's fixable?

I switched o everything off and discounted my pack from the PL8.

The PL8 comes back on. I will wait till I find out what is OCP

[terry2]

this is what I see

[Burgerman]

OCP probably means over current protection. What power supply is it?

Did you set the supply tab correctly to take less amps from that supply than it can provide?
Did you set the power supply volts and amps to max?

The charger is set to 30A. So will take about 35A at 28V to power the PL8. Which supply do you have?

[terry2]

OCP probably means over current protection. What power supply is it?

Did you set the supply tab correctly to take less amps from that supply than it can provide?
Did you set the power supply volts and amps to max?

The charger is set to 30A. So will take about 35A at 28V to power the PL8. Which supply do you have?

Yes you are right (again lol) I had the "Supply Low Voltage Limit" wrong

Its a eFuel 1200W 50A


In the cells tab it says Cell 1=3.589 99% and above it. It says bypass

[Burgerman]

Set about 25V and 50A.

Then in PL8 set supply tab to 10 to 30V and to 47A max...

Cell 1 is much more charged than cells 234567.

So you could charge all cells 1 at a time, till full. Croc clips, no balance wire.

[terry2]

Set about 25V and 50A.

Then in PL8 set supply tab to 10 to 30V and to 47A max...

Will do.
One more thing. In the cells tab it says Cell 1=3.589 99% and above it. It says bypass.

[Burgerman]

Yes thats because that cell is full. All the rest are not. Re read the post above...

[terry2]

Yes thats because that cell is full. All the rest are not. Re read the post above...

Ok. I have read it now.

Will it be ok to leave it charging? No one will be in for and hour or two.
If not I will stop the charge now.

[Burgerman]

Leave it. If its miles out of balance its better to turn off. And charge each cell individually.

[terry2]

Leave it. If its miles out of balance its better to turn off. And charge each cell individually.

Ok I will leave it going.

The person that charged and discharge the cells for me, must have got one one wrong.
I can't complain really.....

[Burgerman]

Turn it off. If thats the case it will sit for hours trying to balance and never get there.

So charge each seperately. Or discharge the full one by the same Ah as the rest.

[terry2]

Turn it off. If thats the case it will sit for hours trying to balance and never get there.

So charge each seperately. Or discharge the full one by the same Ah as the rest.

Will do.

Thanks again.

[Scooterman]

Temporary connections for partially recharging matched cells in 2P8S prior to building the pack. 16 cells in a row are a bit of a stretch for the pigtails, but it's a one off and I'm worn out so couldn't be bothered to rearrange the pack into two parallel packs.

I just wanted to say how nervy I was making all the connections. I dread to think what a nightmare a big pack of headway cells are to arrange

[terry2]

Temporary connections for partially recharging matched cells in 2P8S prior to building the pack. 16 cells in a row are a bit of a stretch for the pigtails, but it's a one off and I'm worn out so couldn't be bothered to rearrange the pack into two parallel packs.

I just wanted to say how nervy I was making all the connections. I dread to think what a nightmare 72 headway cells are to arrange

I felt the same.

My pack has charge and balanced(I think)

[Burgerman]

Scooterman, how do you get all those cells to stick upside down and the laptop too?


Terry, yes it looks balanced and well full.

Now choose discharge, for 2 to 3 hours. And post a screenshot.
All cells should be very close like a single line almost.

Then choose recharge, and they should all be almost completely balanced straight away as soon as the charging finishes.
And another screenshot.

[Scooterman]

I felt the same.

My pack has charge and balanced(I think)

It looks that way. The cells must have been full already because one cell briefly shot high and the whole pack only consumed 0.25Ah before terminating.

But I'll defer to better heads than mine, I'm still learning.

[Scooterman]

Scooterman, how do you get all those cells to stick upside down and the laptop too?

ha Ha! Sky hooks I'm surprised you haven't any

I'm glad I got it done without any bangs, sparks &

[Burgerman]

I wont be needed soon. We have expresso and scooterman, all figuring this stuff out and 3 or 4 others.

[Scooterman]

I wont be needed soon. We have expresso and scooterman, all figuring this stuff out and 3 or 4 others.

Ooh don't say that! You are DEFINITELY still needed