No need for the DC-DC since the OEM alternator voltages and amps are ok with the SiO2. It has the same charging specs as ordinary batteries so no special charger required.
I did change my camper 55 amp converter to a 20 amp charger so not to go over the 25 amp/100AH charging rate they do want you stay under. If I got two 100AH SiO2s in parallel, then the 55 amp converter would be ok. Except I would be broke! One of those is expensive enough. Oh well.
PT says he is saving up to buy six of them! That's a lot of piano tuning. Or he gets paid by the hour and is slow :)
I will not need alternator charging in my scenarios except for an emergency, and apparently doing that will not hurt anything.
It is leaving the fancy batt in parallel with the engine batt with no float voltage, that has "issues" AFAIK, so that's easy- just won't do that.
