start batteries in a house bank

[d design]

The local marine sparky was working on the electrical system on a boat I was working on. I asked him, "Why did you put automotive start batteries in the house bank?" he replied and said, "They say you should use deep cycle batteries but a lot of people dont bother".

Well ive been allways convinced that its a must to use deep cycle batteries. Does anybody here use start batteries in their house bank?

[Steve Strand]

Automotive start batteries will fail pretty quickly if used heavily for "house" duties. Keep him away from my boat. Just cuz lots of people don't bother does not make it a very good idea

[Cheechako]

No, but I did once by necessity. While cruising mexico my new 8D shorted out bad. I went with two mexican group 27 car batteries. Didnt really have an issue, but didnt have a lot of draws on that boat either. :>)
Sounds to me like you need a new electrician. It may matter less on powerboats, maybe he's used to working on those.

[michaelmrc]

i see it many times people doing what they shouldnt be doing with electrical. deep cycle batteries are designed to be discharged and recharged frequently whereas start batteries are designed to spin over an engine for a few seconds then get recharged right away. using start batteries for house bank is a sure way to kill a battery.

[Scott Berg]

Let's see, the electrician knows better but does it anyway? Worse than ignorance is apathy… keep him away from my customers!

[pbiJim]

If the bank only sees use for an hour or two, now & then, & always gets recharged promptly, then car batteries are OK. If the boat sees overnight use, rather than just lunch at the sand bar every other weekend, then you want deep cycle batteries.

[Stumble]

I don't even have a starter battery on the boat. We have enough CCA from a deep cell to crank the engines. The starter battery is 8 years old now and going strong.

[barnakiel]

Depends on how deep you discharge.

I am not sure deep cycles were common say 20 years ago and yet people sailed their boats (with car batteries in house banks) somehow.

So it is OK to use plain batteries in house banks.

It is also OK to have a wooden mast, cotton sails and a kerosene stove.

b.

[d design]

Thanks for the replies. At least he seemd like a nice guy. Hope hes not on these forums lol

[pbiJim]

On small & medium sized motor boats, you also need to worry about how the plates inside the battery are supported mechanically. Constant hard pounding on a car battery, with plates that are only attached at the top, is a sure formula for a short battery life. I've seen a brand new Sears Die Hard killed in less than 2 weeks. It was installed in a 22-foot center console fishing boat that belonged to a guy that liked to get to his favorite fishing spots in a hurry, even in fairly heavy seas.

[Scott Berg]

Originally Posted by barnakiel

Depends on how deep you discharge.

I am not sure deep cycles were common say 20 years ago and yet people sailed their boats (with car batteries in house banks) somehow.

So it is OK to use plain batteries in house banks.

It is also OK to have a wooden mast, cotton sails and a kerosene stove.

b.

My 2nd and third cruising boats had kero stoves (ouch) albeit with alloy spars and dacron sails, but I've used golf cart batt's (deep cycle) for 30+ years as have many cruisers I know… the heavy plates really are important… I do agree that not every change is for the better but heavy plate golf cart or floor polisher batteries have been the standard for offshore cruising at least since the last 1970's

[colemj]

You don't say what your boat is or electrical usage is. If it is a simple boat and you are only starting an engine and occasionally using a cabin light or two or charging a laptop from a small inverter, then an automotive battery may be just fine. If any more than this, then it isn't fine.

Mark