I have a little 30w solar setup, and have a question about charging two batteries at the same time.
One battery is an 80Ah deep-cycle battery that is permanently connected to the system; the other is a 20Ah sealed lead-acid battery I remove for use at night, then want to recharge by day (both are 12v).
Question: Any safety (or other) concerns with just hooking the SLA battery in parallel with the deep-cycle one, given their different chemistries and charge levels? (I understand there's no point in doing this unless the solar panels are generating, but is there a down side/better way?)
Thanks ...