More than two batteries?

[Rod]

Hi All,
Seamonkey has 2 x 12V batteries and driven by a 6HP 4stroke o/b in well. I use the batteries for lighting, charging, tiller pilot etc. Not being electornically minded my question is whether it would be worth installing another 12v battery or not? I do have two solar batteries keeping the batteries topped up. Would a fully charged battery be enough to use a tiller pilot in good weather for an extended period, say overnight? Would I put enogh charge back into the battery from the solar panel during the day to cover that lost in using the tiller pilot?

Thanks,

[storm petrel]

It is not the number of batteries, but whether they are charged and their capacity(measured in amp hours). look up how many amps your tiller pilot uses( I would guess 1 to 2 amps) multiply it by the number of hours you intend to use it between battery charges and then make sure your battery has twice this many amp hours capacity. This will give you a good safety margin. I think it would be better to get a higher capacity battery/ies rather than taking up space and making things more complicated by adding another one.

I have always managed with one (100 amp hour) battery, but I do have an inboard so I am able to motorsail to charge the battery if needed.

Cheers,
Mark

[rob.lovelace]

yeah, what he said:
I also have outboard in well and two 100ah agm (I think agm)
two 40w panels
tiller pilot, a70 plotter ,sounder , led house& nav lights.
I easily get 4 days sailing without sunshine out of them.
after which I need to stop and let thm recharge or recharge
them on the outback charger (50amp alternator on a 50cc Honda)
Seems to be working okay for me.

[rob.lovelace]

and a hungry VHF