I've been testing the new Headway 38120HP cells. Ypedal is absolutely correct, as he has done many testings as well.
These are my findings:
(4s x 4p 32amp/hour pack)
3.5x to 3.6x hot off the charger (per cell)
3.45 resting per cell (13.8v as a pack)
3.28 working per cell (13.12v as a pack) @ 1C 400 watt Resistance Load (4x 100watt lights)
3.16 working per cell (12.64v as a pack) @ 2C 800 watt Resistance Load (8x 100watt lights)
Tests were performed with a Xantrex HF1000 watt inverter powered from 4s x 4p (16 Headway 38120HP 8amp/hour cells)
and home built Light Board for resistance load.
I have a couple of Xcel files with data and graphs.
I'd like to post them, is there a good file share where I can link my files here?
I've also taken temps. Interesting that as the cells get close to being depleted, their temps start to climb rapidly.
From what I've read, this is normal, due to the internal resistance rise. The voltage really starts to drop and the
amperage rises near the end. Hence, temp rise
So far at 1 and 2C, this pack has given me it's rated Amp/hours.