vas
Well-Known Member
morning all,
I've tried and (thought I) succeeded in installing a Victron BMV700 correctly (that was two years ago). However I was always confused as when motoring it didn't seem to report much (if any!) Amps flowing in. Anyway, this summer I installed a Sterling PRO-DIGITAL advanced alternator regulator after servicing the alternator and decided to monitor closely what the alternator produces as I thought it was "hidden" within the amps coming down from the solar panels.
Realised that to the BMV it look like alternator didn't exist!
Last night I realised that the stock wiring from engine to service batteries means that alternator V- is "earthed" on the engine block and via that goes straight to the service battery bank V-. Hence BMV has no record of it
Tested it earlier this morning with solar turned off, at 800rpm amp clamp was saying 20A flowing in the batteries from alternator, BMV was registering -2A (fridge was on...).
Nice, so I was missing 20A in the BMV!
Up till now, I have all loads V- carefully passing through the shunt. Same goes for inputs (solar and battery charger V-) but I completely missed alternator!
So now plan for tomorrow is to disconnect the alternator V- from the engine block and with a decent wire get it back to the shunt (from where it will end up in the bank V-) am I going to be fine registering these amps on the BMV.
Doubt I'm going to be the only one doing this elementary error, so if you're missing amps, check the V- alt wiring back to the battery bank.
Of course the above doesn't apply if the block earth wire goes straight to the shunt and not to the V- first (doesn't on mine as there are two engines and two battery banks with engine blocks wired together and to the engine bank V- and there's a "bridge" from engine bank V- to service bank V-. Of course I could leave alternator wiring as is, and route this bridge to the shunt. Maybe easier than isolating alt V- and rewiring to shunt!
Thinking about it as I type I'll do that and skip new wires going about in the e/r
cheers
V.
I've tried and (thought I) succeeded in installing a Victron BMV700 correctly (that was two years ago). However I was always confused as when motoring it didn't seem to report much (if any!) Amps flowing in. Anyway, this summer I installed a Sterling PRO-DIGITAL advanced alternator regulator after servicing the alternator and decided to monitor closely what the alternator produces as I thought it was "hidden" within the amps coming down from the solar panels.
Realised that to the BMV it look like alternator didn't exist!
Last night I realised that the stock wiring from engine to service batteries means that alternator V- is "earthed" on the engine block and via that goes straight to the service battery bank V-. Hence BMV has no record of it
Tested it earlier this morning with solar turned off, at 800rpm amp clamp was saying 20A flowing in the batteries from alternator, BMV was registering -2A (fridge was on...).
Nice, so I was missing 20A in the BMV!
Up till now, I have all loads V- carefully passing through the shunt. Same goes for inputs (solar and battery charger V-) but I completely missed alternator!
So now plan for tomorrow is to disconnect the alternator V- from the engine block and with a decent wire get it back to the shunt (from where it will end up in the bank V-) am I going to be fine registering these amps on the BMV.
Doubt I'm going to be the only one doing this elementary error, so if you're missing amps, check the V- alt wiring back to the battery bank.
Of course the above doesn't apply if the block earth wire goes straight to the shunt and not to the V- first (doesn't on mine as there are two engines and two battery banks with engine blocks wired together and to the engine bank V- and there's a "bridge" from engine bank V- to service bank V-. Of course I could leave alternator wiring as is, and route this bridge to the shunt. Maybe easier than isolating alt V- and rewiring to shunt!
Thinking about it as I type I'll do that and skip new wires going about in the e/r
cheers
V.
