Solar and VSR relays
Hi this is my first post I’m interested in vehicle solar installation, My solar set up is as follows was wondering if all sounds ok??? During sunlight voltage at leisure battery showing 13.3v 14...
Forum Discussion
This is a strange set-up.
No, there is no problem for the starter to be attached to both batteries if both are good. If the coach battery (leisure) is low, then that could possibly pull enough amps out of the starting battery to not start the motor (just depends on a few factors).
Curious, why do you need to put solar on the starting battery? Is it stored for long periods of time? If not stored, then the starting batt really does not need solar. If stored, then it is better for the batteries to each have its own charge controller. You are charging a starting battery and a marine battery, two different types, from one source. The chargers are smart, but there will be confusion from mixing batts.
A 20 watt solar panel is plenty to keep starting battery topped off for storage, and a $19 controller will do the job.
The relay is to disconnect the batteries when the alternator is not charging, this keeps one from draining the other battery, so you can start motor even when the coach batt has been run dead. Usually the relay has a switch connected to the ignition so when the starter is turning the relay disconnects the two batteries from each other. You notice your radio turns off when you crank the motor, the same will happen on the relay, it will turn off (disconnect the two batteries).
I would discourage charging both batteries from one solar source.
I would install a switch to manually turn on/off your relay from the vehicle alternator to the coach battery. With solar you might not need the alternator very often. The alternator is not as good of a charger than the smart solar controller, though the alternator does has the sheer power in amps to do the job quick, so if batts are dead, do a couple hrs charge to get them near full, then let the solar take over for the final few percentages (I dont know how you would know when to do this though).
With more info I might can have more advice if this is of interest
No, there is no problem for the starter to be attached to both batteries if both are good. If the coach battery (leisure) is low, then that could possibly pull enough amps out of the starting battery to not start the motor (just depends on a few factors).
Curious, why do you need to put solar on the starting battery? Is it stored for long periods of time? If not stored, then the starting batt really does not need solar. If stored, then it is better for the batteries to each have its own charge controller. You are charging a starting battery and a marine battery, two different types, from one source. The chargers are smart, but there will be confusion from mixing batts.
A 20 watt solar panel is plenty to keep starting battery topped off for storage, and a $19 controller will do the job.
The relay is to disconnect the batteries when the alternator is not charging, this keeps one from draining the other battery, so you can start motor even when the coach batt has been run dead. Usually the relay has a switch connected to the ignition so when the starter is turning the relay disconnects the two batteries from each other. You notice your radio turns off when you crank the motor, the same will happen on the relay, it will turn off (disconnect the two batteries).
I would discourage charging both batteries from one solar source.
I would install a switch to manually turn on/off your relay from the vehicle alternator to the coach battery. With solar you might not need the alternator very often. The alternator is not as good of a charger than the smart solar controller, though the alternator does has the sheer power in amps to do the job quick, so if batts are dead, do a couple hrs charge to get them near full, then let the solar take over for the final few percentages (I dont know how you would know when to do this though).
With more info I might can have more advice if this is of interest
