Mick,
No matter how much you want to help this guy, you already know the
answer to this in your gut. Maybe I'm being overly cautious here, but
this seems to be the same as what we would tell folks trying to combine
different sizes and ages of FLA battery: Don't do it. He should sell
the E vault to a neighbor, and run the new cab, or (just like with FLA)
put in a battery selector switch, and run the system on one or the
other, and change settings each time (ugh). Honestly I just don't see
it working out very well, and I could see one battery powering into a
problem in the other battery and Really having bad things happen.
I'd give it a 10% chance it will work just fine, a 30% chance it will
work OK, but need periodic charging on one battery or the other to sync
them, a 40% chance it will lead to premature failure of one or both
batteries, and a 20% that you let the smoke out of one or the other BMS
units and/ or do cell damage. (just my educated guess, but check with me
in 5 years and see how the dice roll worked out)
I'm sure there's some DIY folks that have done all sorts of wild mixing,
but that still doesn't mean it's a good idea.
War stories? I've already had so much trouble with various LiPO4, that
I definitely don't feel like being adventurous. I've had a Simpliphi
bank smoke all the control boards, Home grid system shut down
intermittently and need to be dark started every couple of months,
Fortress evault shut down at 100% SOC because of a firmware issue and
leave a freezer full of elk rotting.....and I definitely am not trying
any lunatic fringe stuff.
Sincerely;
Ray Walters
Remote Solar
On 10/14/2025 4:18 PM, Mick Abraham via RE-wrenches wrote:
Hi, Wrenchies~ I sold one E-Vault Classic cabinet to an off-gridder in
2021 (18.5 kWh rated). He set it up open loop even though he's got
Schneider XW Pro. Now he'd like more storage and asked for a quote on
one EG4LL-S cabinet, fully loaded (30.7 kWh).
Surely he would have to stay open loop if these two brands are
combined. Both brands have 16 cells in series = 51.2 nominal volts.
However, EG4 documentation calls for 56.2 volts Bulk & Fortress calls
for 54.4 volts Bulk.
War stories or suggestions welcomed; thanks in advance. The Wrench
List is the Bomb!
Mick Abraham, Proprietor
www.abrahamsolar.com <http://www.abrahamsolar.com>
Cell phone or for text messaging: 970-946-6584
_______________________________________________
List sponsored by Redwood Alliance
Pay optional member dues here:http://re-wrenches.org
List Address:[email protected]
Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
There are two list archives for searching. When one doesn't work, try the other:
https://www.mail-archive.com/[email protected]/
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
List rules & etiquette:
http://www.re-wrenches.org/etiquette.htm
Check out or update participant bios:
http://www.members.re-wrenches.org
_______________________________________________
List sponsored by Redwood Alliance
Pay optional member dues here: http://re-wrenches.org
List Address: [email protected]
Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
There are two list archives for searching. When one doesn't work, try the other:
https://www.mail-archive.com/[email protected]/
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
List rules & etiquette:
http://www.re-wrenches.org/etiquette.htm
Check out or update participant bios:
http://www.members.re-wrenches.org
