PowerLab 8 + Li-Ion = Failure

[Marshall]

I guess I just don't know how to set up a profile for li-ion batts of IMR/NCR etc chem type on the PL8.

I've tried all the way up to the powerful Feilong 6000mAH 32650 cell (unprotected) for li-ion, known to be a powerful cylindrical cell, and I am getting a "cell overvoltage". Basically, watching the fuel the battery goes from 50% charge, to 99%-101% charge within the first few seconds of the charge and jumps around 100% either triggering finished or triggering overvoltage. I have tried going all the way down to 300mA charge rate, on the default "Accurate Charge" lithium and "charge only". I have successfully charged 26650 protected and non-protected cells at a low amperage (250mA), but anything higher like 500mA and the same results occur. I am running straight bananas to a battery holder, single cell at a time, so no balance.

"What is up with Li-Ion batts on a PL8?"

Obviously I have it all wrong and need to create a profile for these, because the chinese wall chargers I'm using are charging them at 1-1.5A, 3000mAH-6000mAH battery sizes of lithium ion.

[pescador]

I think the cells you are trying to charge might be "A123" or "LiFe". They peak at a lower voltage than regular lipo's. Try one of the A123 presets.

[Marshall]

Actually, they are in fact all, 4.200V = full charge, cells. I understand how you might think they are different by the fact they aren't taking a charge correctly as I describe, but the cells I am running are definitely NOT stated as A123 or less than 4.2V (3.7V). I have some small A123s and they would certainly not work on the same charger as these. These are cells that are extremely common in high-end or even common, high-power-low-dollar, LED flashlights. Something that may need to pull a constant 1A-5A would use these cells (just like a light!), but definitely not a cell for huge current bursts like we use around here to power brushless motors.

I am thinking it is some problem maybe more along the lines of constant-current vs constant-voltage charge type etc.

When I test a charging cell that is on a standard 26650/18650 wall charger, the cell voltage is slowly rising during the charge to 4.20V. When I test the voltage (and I know the battery is at only 40-50%), but it's being fed 300mA by the PowerLab 8, my meter shows 4.2V constant during the charge. That appears to be the main difference. How can a wall charger feed 1A to the cell differently to not cause this problem, and how might I mimic that with a PL8 setting?

[pescador]

Rats I thought that might have been it, I only suggested it because when I was looking up the cells they mostly showed 3.7v.
I would try the forum on RC Groups, Tim Marks from Revolectrix is usually answering questions there.

[Marshall]

RC Groups you say? Let me look it up. Thanks. I know we had some PL8 users here, more than most forums (probably due to our pack requirements), but I will look.