Originally Posted by clloyd
So let me process this. 4x 12v/90ah batteries is 360ah total in a parallel start bank? 1 or 2 or both?, so 2 x 180 ah banks that can be combined for a 360ah bank.
I actually don't know what the big outboards require but that seems fairly massive.
Typo? I'm guessing you have 4x45ah batteries instead.
For example my large single diesel uses a 2 x 12v/45ah batteries for a total of 90ah/12v in my start bank. So that would mean you have four times that.
Reason I'm curious here is that I am redesigning my banks so been researching battery specs quite a bit. I have dual 24v and 12v to deal with which makes things dicey.
Weight does matter.
2 x 45ah batteries is about 75lbs
1 x 23 ah house is 26 lbs
4x90 ah I would calculate at like 300lbs
I have a 24v start bank so I need to add in pairs 12+12.
Sorry for the confusion. English is not my first language and it shows, obviously.
The weight of the boat is of very little concern to me. I understand the penalty of weight and the expansive t-top's windage on the boat's speed and I do not expect my Zodiac to be the fastest. If I wanted to have a light vessel, I'd had better bought a carbon RIB or a catamaran. My boat will be operating in the chop in shallow tidal waters and I hope that the deep V of the hull and weight will help a bit.
Sorry, I was not clear with my wording in my previous post.
We have three bank, two outboard electrical system. The wiring was done per BEP Marine recommendations :
717-140A-DVSR Twin Outboards, Three Battery Banks
We installed two starting (cranking) battery banks, one bank per engine. Every bank consists of two batteries recommended by my shipyard (AGM 12/90 Ah) in parallel.
The Mercury 150 four-stroke Manual recommended one 1000 marine cranking amps (MCA), 800 cold cranking amps (CCA), or 180 ampere hour (Ah) battery per engine. We installed two smaller units for every engine.
I have a 5.5 meter RIB now with one Yamaha two-stroke and we have two batteries for the engine; one engine acts as a house /reserve battery and I wanted to have a separate house battery and the VSR allows us to connect it to any engine for starting.
There is no towing service, the rescue is done by the Navy, and the navy is 30 nm from me, and I think that having a house bank or a battery could be helpful even on a 23' RIB.
Sorry, I cannot comment on the diesel engines because I have very limited experience with them.