coming out of the charge controller into a Victron Energy ArgoDiode Battery Isolators 80-2SC
that will charge my solar battery bank
and my golf cart on the leg
will this work or is there a better way
1 Like
If both batteries have the same chemistry and you’re OK with the more empty one being charged first… that setup will work for you.
If your batteries differ in chemistry and/or you want to have more control (like: charging the solar bank should have priority, while golf cart should only charge if the solar bank is full enough) then a DC-DC converter (that you can control using its external enable, f.ex. by using the relay in your charge controller or a GX) could be the way to go.
thanx, yes same brand same 100ah
1 more question if the battery’s on the golf cart are drained iam worried about a spark would a resistor help like when i pre load the inverter
i do have a 250/70 Charge controller & cerbo Gx, thinking i have to slow the amps down so i dont hurt the
golf cart batteries
An empty battery is no capacitor (that is charging with what is available, but also quickly being fully charged), so a resistor likely wouldn’t help that much here.
One option would be to wire a switch to the external enable of the MPPT, to disable it (stopping any energy from flowing toward the batteries) while you’re connecting the mobile battery.
An option to not shut down the charger could be to put a reasonably sized TRIAC into the connection toward the mobile battery, similar to the following diagram:
- Lamp Load being your mobile battery
- Vs the connection to the stationary system, with (+) being the output of the Argofet and the other to common (-)
- SW1 being a push button (self resetting, NO - Normally Open), not a switch
- an additional, strategically placed fuse to protect from short circuit
This would give you a cheap charge control circuit, with a button to start the charging: triggering the TRIAC once will keep it latched on as long as energy is flowing through it toward the battery (it’s DC: so no zero cross which would normally clear the TRIAC as with AC), which will turn itself off when the battery is fully full (no more power flowing), you pull the plug (breaking energy flow, clearing the TRIAC) or the charge controller in front of the Argofet stopping to deliver (dito).
That would allow to use a low power switch, as the load goes through the TRIAC: no sparks.
But both options could lead to overcharging the cart battery, destroying it in the process.
And the TRIAC one to not (fully) charging because there is even a marginal power supply outage - or the sun going down, requiring another button press in the morning).
Thus the best option, IMHO: use a DC-DC converter (sourcing from the main battery bank), as that could run a multi-stage charging profile tailored to the cart battery, keeping it alive as long as possible… and you could do the same thing with the low power external switch (to have no sparks while connecting), just connecting it to the external enable of the DC-DC.
Then you could also wire that control line (in all variants) through the relay of the MPPT (set to only be closed when there is enough solar power to actually charge the cart, so you won’t create extra cycles for your main bank).
Or put an even smarter control logic into the Cerbo (using NodeRed and one of the cerbo relays).
edited
OK thanks for the great advice on second thought, i do have a xtra victron 100/50 charge controller, think i will just bolt it to the cart then just plug it into my solar array 2 panels will get me 70 volts and 600 watts WDYT