Hi Jason Wow just wow. That’s so screwed up on so many levels. Obviously designed by someone who’s never installed, repaired or designed anything.
I agree with EG4. They might actually be the largest single supplier in the USA feom one source I talked to. I don’t think anyone yet has combined all the needed ingredients for the perfect battery. Jay > On Feb 11, 2025, at 4:37 PM, Jason Szumlanski via RE-wrenches > <[email protected]> wrote: > > > Hi Wrenches, > > I am regretting some HomeGrid Stack'd off-grid installations right now. There > is a major flaw in the way these function in an error state. For those of you > that don't know, these 48V batteries are stacked with a single BMS on top, > covering up to 8 batteries below. Each battery module has a circuit breaker > and dip switches to identify the battery communication number and location in > the stack. Each BMS can be paralleled to additional stacks with communication > cabling. > > The issue is when one battery module goes into an error state. What will > happen is that battery stack's BMS will recognize the error, and then shut > down the whole stack. This cascades to the other stacks and the system shuts > down - fails to deliver 48V at the output terminals on the BMS of any stack. > > That is annoying, but what's even more problematic is you can't just shut off > the offending battery to bypass it. You need to physically change all of the > dip switches to bypass it and then reprogram the BMS to re-recognize the new > module count (after taking it out of parallel). This is all very time > consuming and requires the inverter system to be shut down. Even if a battery > is not in an error state, you can't just turn it off. The whole system goes > haywire. > > Once you have it bypassed, you can hook up a RS-232 cable (Mac users need not > apply) and use their software to gather diagnostics. Customer service will > then want to do additional diagnostics with the battery in the stock, but > that is not reasonable in and off-grid system where uptime is critical. One > of the faulty modules I am dealing with was diagnosed as one of 15 cells with > low voltage. The "solution" is to take it out of the stack and charge it to > 100% with an external charger. > > By the time I'm done with all of the diagnostic nonsense, I can almost pay > for a new battery with the lost labor. Isn't the whole idea for this not to > happen with balancing done automatically? It was suggested to me that it > didn't get charged to 100% often enough, and that is why it happened. That > isn't an acceptable reason for failure in an off-grid system. > > I hate to say this, but EG4 has a far better 5kWh solution in this respect. > Each module has it's own BMS. When one fails, you can simply turn off the > circuit breaker and everything else continues to work. In fact, a fault in > one BMS doesn't take out the whole stack or stacks of battery modules. > > Back to HomeGrid. When this happens, in my mind this is an automatic RMA. > They should be replacing these, no questions asked. Especially at almost > twice the price of EG4. They actually want me to disassemble the case of the > battery and charge it with an external charger (which I don't have) directly > from the terminals that are internal to the battery case. Totally > unacceptable. Whatever is inside that case is their problem in my opinion. > > I am not selling anymore HomeGrid until I get satisfactory resolution to > these issues. EG4 isn't perfect, but I have actually had pretty good success > installing some that I sold and quite a few that consumers purchased > directly. And at almost half the price, it's easier to eat the cost of a > battery here and there for customer satisfaction. > > Anyone have similar issues with HomeGrid? > > Jason Szumlanski > Florida Solar Design Group > _______________________________________________ > 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
