Ideas on reconfiguring a Ping pack

[grimbasement]

I have a 48 V 20 Ah ping pack that I bought last year that I puffed some cells on by running regen too soon on a fullish battery (It also could have been the balance wires had an issue which is why the last 4 pouches on each side puffed. or It could be I left the BMS connected for too long this past winter).

I finally decided to cut the bricks open see if I could salvage some of the pouches. Turns out 4 pouches (8 total) of the packs were puffed so I lost about 7 V. I cut off the puffies and remaining pouches are all balanced at 3.4 V and haven't been on a charger in a year so the remaining cells are good. I'm not interested in further breaking down the pack so I'll solder them together and combine the 2 packs into one for some extra range on some touring rides. Question is how can I handle the BMS? I have a few working Ping Signal Lab BMS hanging around but with 2 less cells how will balancing work? I think I have read that the Signal Lab BMS can be used with fewer than the number of cells but I'm wonder about how to keep the cells balanced long term can the Ping chargers do it or should i just plan on balancing with a single cel charger

I should still be able to get 50.4 V off the charger on the pack and I can pot down one of my chargers if needed.

 

[dogman dan]

Easiest thing would be snipping off more cell groups, to make a 36v. Then put a 36v bms and charger on it.

Or, get some cells to replace the bad ones.

Or, run without a bms. That might be acceptable, for a seldom used range extender. Fit the pack with some jst plugs you can use a cellog 8 with, so you can keep an eye on voltages. Practice a conservative stopping point too.

Your adjusted charger can still charge it, you just have to monitor it in the last hour with those cellogs. Stop when one cell fills, then discharge that cell some with a light bulb.

Or, break in in half, and use an 8s RC charger to balance charge each 7s section.

 

[999zip999]

Make sure you put some sense wires on the cells for easy checking and balance charging with or without bms. Meaning as you wish. Those balance wires make for easy monitoring. Yes 8 pouches is a lot of money. Sorry you had to learn the hard way. The battery dosn't come with a fact sheet for care and storage.

 

[gogo]

The battery dosn't come with a fact sheet for care and storage.

My 2009 Ping battery came with instructions to unhook the BMS while stored and that it should be charged periodically.

 

[dnmun]

can you post up a picture of the pack so we know which pouches your removed and do you have the v1 or v2.5 ping BMS? what kind of charger do you have and can it be adjusted to lower voltage?