Best way to start a 2-wire genset on %SOC when inverter is dumb

[HughF]

I've been using outback VFX inverters since 2006 or so, and they are utterly reliable, I don't really want to change at the moment. I currently use a flexnet DC for %SOC monitoring and after months of tweaking, it tracks the batrium %SOC near enough perfectly. This %SOC is then used to start/stop my genset using Outback's AGS feature.

I assume that a better way going forward would be to use a Victron Cerbus GX, which will talk natively to my new battery bank (I'm building up a Seplos Mason 280 using EVE 304K cells) to control my genset and leave the outback just to do charging? Unfortunately the outback stuff is too old to talk to any LFP batteries, irrespective of protocol.

Despite my best efforts at research, I can't find if the Seplos BMS has the ability to do relay output based on on %SOC that could easily be used for generator start control.

 

[Checkthisout]

Start on voltage instead of State Of Charge.

 

[HughF]

Start on voltage instead of State Of Charge.

I think I’ll stick with SOC, but thanks for your comment anyway….

Back to the task at hand, seems like both seplos v3 and JK have dry contacts. The seplos one appears to be undocumented, but the JK one works well (according to latest OGG video)… that’s seems a sensible way to go.

 

[Checkthisout]

I think I’ll stick with SOC, but thanks for your comment anyway….

Back to the task at hand, seems like both seplos v3 and JK have dry contacts. The seplos one appears to be undocumented, but the JK one works well (according to latest OGG video)… that’s seems a sensible way to go.

Ok.

I would guess the contacts in the BMS are intended to be used to open and close on low voltage so they can be used to control an alarm or something.

BMS's aren't really intended to be used for generator start or a/c input management.

 

[HughF]

Ok.

I would guess the contacts in the BMS are intended to be used to open and close on low voltage so they can be used to control an alarm or something.

BMS's aren't really intended to be used for generator start or a/c input management.

JK is fully programmable to open/close on any user selectable parameter.

If I can’t get the bms to do it then I’ll use a cerbo gx, or build something from a canbus shield and an arduino.