it depends on your amp/hr usage in a day. on a 105 ah battery a 60 ah day will bring it down to 50% charge. the out board would have to be run at least 1/3 throttle for 5 or more hr's a day to bring it back up to full. If batteries were in parallel it'd come down too 70 or 80% With a honda 2000 you could run an AC to DC 30 amp charger
, cutting your charging time to 2 to 3 hrs. trying to charge both 105 from 70% or less will overload your outboard
charger. alternators or magneto charger outputs should be at least 1/3 of the amp/hr rating of the battery bank. the outboard is designed to charge a cranking batt. from no lower than 80% doing more is OK once in a while but not regularly.
that said, I'd run parallel and add a starting bat on a two bank batt. switch. when you go on the hook try to get at least 250 to 300 watts of solar
is the best combination tho.
with a hundred watt wind
and 205 watt solar south of the 26th parallel I get 120 amp/hrs a day ( i could try to conserve more ;-) but hey? ). Refrigeration/freezer, lighting
- for computer/ entertainment and running/charging other DCV electronics
. I don't like buying
fuel/gas, so I keep it to a minimum. my 4D batteries stay right around 12.7 to 12.9 and I only have to add water
about once every 7 to 8 months...about a pint each batt. on house bank. only once in two years on the engine
batt. the smaller the charge/disgharge ratio the long the batt. life.