Charging House & Starter Battery with One MPPT Controller - 1/2/Both Switch

[smac999]

why do you need to charge the engine battery?

how do you currently charge both banks from the engine?

[TJ11]

Originally Posted by Stu Jackson

New info, changes the answer.


Get a combiner, echo charger or any other VSR to charge both banks when you're away from the solar you have.


OR, since you won't be there, wire the banks together. Since there shouldn't (?) be any loads, it doesn't matter if the chemistry is different.


What are ACRs, Combiners & Echo Chargers? (by Maine Sail) [scroll to the top]
http://forums.catalina.sailboatowner...d.php?p=742417 and http://c34.org/bbs/index.php/topic,9....html#msg70131

Making Sense of Automatic Charging Relays (2019)
https://marinehowto.com/automatic-charging-relays/

This is great. Thank you Stu!

[stormalong]

"OR, since you won't be there, wire the banks together. Since there shouldn't (?) be any loads, it doesn't matter if the chemistry is different."

That is not right. Different battery chemistries, even different battery age or manufacturer means different rested voltages. The higher voltage battery will continuously discharge into the lower voltage battery. Leaving this unattended for long periods of time means sure death for both batteries