Alternator overcharging batteries
I have 4 AGM batteries in my rig with a total capacity of 440AH (actually 880AH @ 6V, but of course they are wired to get 12V). The data sheet for my Haze batteries species a bulk -> absorption cut...
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If you are using one of those smart solenoid relays like Sure Power or Blue Sea has it will only charge the external batteries when the truck start battery is being charged.
The main reason for this is to not over-charge the external wet cell flooded deep cycle batteries. This was probably incorporated because the external batteries may too far away from the alternator charge systems that the truck battery system really doesn't know it has an external battery setup connected.
The smart solenoid relay senses when the truck alternator system hits the 14.2 VDC charge state and connects to the external battery when that happens. When the truck system drops back to the 13.6VDC and 13.2VDC modes on the truck side then the smart mode solenoid will drop off the external battery connection.
This also keeps the external battery system from discharging the truck start battery system which is what you really want to happen.
I know BLUE SEA has a great writeup on the SI-ACR SOLENOID RELAY on how its works.
I am only referring to the external battery being a wet cell deep cycle battery and maybe the other style deep cycle AGM batteries need different charge voltages.
Roy Ken
The main reason for this is to not over-charge the external wet cell flooded deep cycle batteries. This was probably incorporated because the external batteries may too far away from the alternator charge systems that the truck battery system really doesn't know it has an external battery setup connected.
The smart solenoid relay senses when the truck alternator system hits the 14.2 VDC charge state and connects to the external battery when that happens. When the truck system drops back to the 13.6VDC and 13.2VDC modes on the truck side then the smart mode solenoid will drop off the external battery connection.
This also keeps the external battery system from discharging the truck start battery system which is what you really want to happen.
I know BLUE SEA has a great writeup on the SI-ACR SOLENOID RELAY on how its works.
I am only referring to the external battery being a wet cell deep cycle battery and maybe the other style deep cycle AGM batteries need different charge voltages.
Roy Ken
