Capacity test Problem

[squowse]

Mine seems to disconnect at 2.6 v

change disconnect to lower setting

 

[Gazoo]

I don't have one of these testers but from what I have read the voltage always seems to be .2 to .3 of a volt off when the capacity test is finished. For example if the voltage is set to 2.5 volts the tester will disconnect when the cells voltage is 2.8 volts or so all because of the nasty voltage drop. Therefore as squowse suggested try lowering the voltage to 2.3 volts and see if that helps.

As others have suggested check your connections and crimps. If that really is 12awg wire then that should be fine. Finally from what I know these testers get extremely hot and some have smoked when set at the full current they are capable of. So I would lower the current as well.

​

 

[squowse]

I don't have one of these testers but from what I have read the voltage always seems to be .2 to .3 of a volt off when the capacity test is finished. For example if the voltage is set to 2.5 volts the tester will disconnect when the cells voltage is 2.8 volts or so all because of the nasty voltage drop. Therefore as squowse suggested try lowering the voltage to 2.3 volts and see if that helps.

As others have suggested check your connections and crimps. If that really is 12awg wire then that should be fine. Finally from what I know these testers get extremely hot and some have smoked when set at the full current they are capable of. So I would lower the current as well.

​

varies with voltage as well. I run mine at 17A for long periods

 

[Hedges]

While current is being drawn, measure voltage drop across each interface and along each wire.
You should be able to measure drop from crimp terminal to copper wire, from aluminum cell terminal to crimp terminal, from one end of wire to the other.

Also measure voltage at load tester terminals with meter, compare to what its display reports.

 

[Baserati]

So it looks as though the culprit is my connection at the cell. See voltages below

on Display = 3.06
at Load tester terminals =3.168
At Battery-on top of connectors = 3.188
On Battery Terminals = 3.275

 

[Hedges]

I was thinking it could be aluminum oxide.
If you scrub off the oxide and use inhibitor that may help.

But drop from load tester terminals to display is similar.

 

[Baserati]

Thanks, this is a good lesson in importance of good connections