View Single Post
Old 07-18-2016, 10:58 AM   #8 (permalink)
Master Novice
elhigh's Avatar
Join Date: Jan 2008
Location: SE USA - East Tennessee
Posts: 2,310

Josie - '87 Toyota Pickup
90 day: 27.96 mpg (US)

Felicia - '09 Toyota Prius Base
90 day: 47.83 mpg (US)
Thanks: 424
Thanked 609 Times in 447 Posts
You're describing recalibrating. I suspect you may have a few weak cells in your pack. As you use charge from the pack, those cells go below a certain cutoff voltage before the others do. When that happens, the system automatically bottoms out the meter and forces a charge cycle on the pack until the pack indicates that it's full. I'm not 100% on the processes at play here and if EM member S Keith comes on and says something different, listen to him. It was his guidance that walked me through getting my pack back in order.

I purchased a grid charger from Hybrid Revolt and wired it in. Took an afternoon - evening, really, and it was cold, and it didn't take long. That kept my system working okay for a while. Then I started getting more and more recals and the IMA light came on and stayed on. Obviously grid charging, while helpful, isn't everything you need.

Then I followed instructions to build a discharger. Following (some of, because I am a bit pigheaded that way) S Keith's advice I pulled the entire pack down to a total of about 55v DC. S Keith told me he has discharged packs all the way down to 2.0V DC, which is about as dead as a battery can get when you consider that total of 2.0 volts is coming from 144 cells. Done gently, it doesn't harm the cells. I have been enjoying a nearly-new performing IMA battery, though it seems to me that it's begun to get a little out of balance again and the next time I do the discharge, I'll pull it deeper.

I think your HCH is a generation newer than mine, but this was the process I followed when I was experiencing some symptoms similar to yours, and it has been working well since. For a few bucks building a discharger is easy.

Lead or follow. Either is fine.
  Reply With Quote