Yanmar 6lp required battery ?

[ed c.]

We had a discussion regarding battery group. The new 27 group has a lot more starting and reserve power than the earlier ones. We have 2 group 31's for starting and a D for the house batt. My son wants to use the group 27 and it has quite a lot of power. Does anyone have any thoughts on this.

[Navatech]

We had a discussion regarding battery group. The new 27 group has a lot more starting and reserve power than the earlier ones. We have 2 group 31's for starting and a D for the house batt. My son wants to use the group 27 and it has quite a lot of power. Does anyone have any thoughts on this.

My thought would be to have a battery for each engine plus a house battery... Depending on your needs you can read bank (multiple batteries) for "battery"... One caveat would be that you should be able to start your engines off any of these three batteries... In addition, bringing aboard a booster pack will give you some independent redundancy...

That's roughly what I have on my boat... My situation is somewhat different because of legacy issues and the original design which called for a mixed low voltage system being compromised of both 32 volts (starting of the main engines and most everything else on the boat - lights, heads, fresh water pump, bilge pumps etc) and 12 volts (generator starting and bridge - navigation lights and instruments)... I can start the main engines of either 32 volts bank as they can be "combined"...

In addition, I have a 12 volt battery to start the generator and a 12 volt "house" battery... These can also be "combined"... Since I have onboard (110 volts) chargers for both low voltage systems and can therefore start up as long as I can get the generator running I have two alternate means to start the generator... A booster pack and a small portable gas generator (110 volts)... I can either use the booster to start the generator or use the portable generator to run the onboard charger in order to start up the main generator...

The portable gas generator also serves as the power source for an emergency submergible pump...

And yes, having two kinds of fuel (diesel and gas onboard) is a PITA but let's face it, I have gas onboard for the dinghy's outboard anyway...

[SteveM]

I have group 27's with those engines. One battery per engine. One for the "house". All switchable among each other.
Curious if anyone has preference of battery type in this scenario. Water battery, AGM, Gel???
I've got all Water batteries.