What battery for engine starting?

Post Reply
Alastair Miller
Posts: 48
Joined: Mon Apr 13, 2009 9:33 pm
Anti Spam measure: Yes
AntiSpam Text: Westerly

What battery for engine starting?

Post by Alastair Miller »

Hi, I'm looking for some advice on choosing a battery for starting a VP 2002 on my Merlin. I suspect the existing battery which was fitted by a previous owner is now end of life. It is marked with a name I can't find any info on and rated at 105AH though I have no idea if it is a 'proper' engine starting battery.

The more I look at online suppliers the more confused I get as to what type of battery I should get. Also what constitutes a marine starter battery , what is the difference between this and a car battery, are dual function batteries any good etc etc.

My sailing habits are generally light leisure usage with a short engine run out from and into harbour on day trips and I don't see a need to go for high spec battery technology. I am aware the Volvo manual quotes a max rating of 70AH but I am also aware that the online consensus is that this is a meaningless term

So recommendations and experiences gratefully received

regards
Alastair
mikebuggy
Posts: 137
Joined: Tue Jan 20, 2009 5:42 pm

Re: What battery for engine starting?

Post by mikebuggy »

I know I'll probably be cast into outer darkness by other responders for what I'm going to say. Ive always used on every boat, for every purpose, the same batteries. Good old fashioned straightforward liquid filled black lead acid batteries. I use them for everything from leisure and domestic use to engine starting to windlass etc. I dont use any splitters, diodes, combiners, or anything clever. I have a simple on\off\1\2\all rotary switch hardwired to the batteries. When i had small boats I just had 1 battery on each circuit. With a bigger boat I have 4 in parallel on one circuit and 1 on the other. I tend to use the simple 1 battery circuit for engine starting. When this has recharged after a short while of running I switch over to the 2nd circuit, which I stay on until the engine is next used. Sometimes I forget though, and just leave things on 1 or 2 or All whatever Im doing. It doesnt really matter. What I am careful about though is to only use the domestic bank (2) when at anchor or without power. This means the single engine start battery is never drained.
Simple Lead acid batteries are relatively cheap, rugged, and reliable. Ive never sought out any particular brand or quality....just something reasonable....usually at a good price....preferably in a sale. I don't buy ones that are suspicously very cheap or look flimsy. The 'industry standard' for rugged Lead Acid batteries is the 110AH size and this is what I always use. They fit pretty well everything. They have always lasted a long time, years and years, whatever I do to them, and I do use a lot of power. The pundits will always say you must use a 'leisure this...' or a gel sealed that.....' etc, but I've never found it so.
TyroSailor
Posts: 630
Joined: Mon May 18, 2015 6:48 pm
Anti Spam measure: No
AntiSpam Text: Westerly

Re: What battery for engine starting?

Post by TyroSailor »

How do you keep the acid in the batteries when the boat jumps about, Mike? And what would happen in the event of a knockdown, or worse?
Experience: That which would have been most useful five minutes before you acquired it.

Steve
Tyro (Centaur 1361)
at Southampton
mikebuggy
Posts: 137
Joined: Tue Jan 20, 2009 5:42 pm

Re: What battery for engine starting?

Post by mikebuggy »

Well, the batteries do have little screw cap thingies.....?
The liquid has magically stayed in for 50,000 odd miles include several transatlantics and many gales.....I must be doing soemthing wrong!
User avatar
aquaplane
Posts: 484
Joined: Tue Jan 13, 2009 10:42 am
Anti Spam measure: No
AntiSpam Text: westerly
Location: Windermere/Tayvallich
Contact:

Re: What battery for engine starting?

Post by aquaplane »

mikebuggy wrote:I know I'll probably be cast into outer darkness by other responders for what I'm going to say. Ive always used on every boat, for every purpose, the same batteries. Good old fashioned straightforward liquid filled black lead acid batteries. I use them for everything from leisure and domestic use to engine starting to windlass etc. I dont use any splitters, diodes, combiners, or anything clever. I have a simple on\off\1\2\all rotary switch hardwired to the batteries. When i had small boats I just had 1 battery on each circuit. With a bigger boat I have 4 in parallel on one circuit and 1 on the other. I tend to use the simple 1 battery circuit for engine starting. When this has recharged after a short while of running I switch over to the 2nd circuit, which I stay on until the engine is next used. Sometimes I forget though, and just leave things on 1 or 2 or All whatever Im doing. It doesnt really matter. What I am careful about though is to only use the domestic bank (2) when at anchor or without power. This means the single engine start battery is never drained.
Simple Lead acid batteries are relatively cheap, rugged, and reliable. Ive never sought out any particular brand or quality....just something reasonable....usually at a good price....preferably in a sale. I don't buy ones that are suspicously very cheap or look flimsy. The 'industry standard' for rugged Lead Acid batteries is the 110AH size and this is what I always use. They fit pretty well everything. They have always lasted a long time, years and years, whatever I do to them, and I do use a lot of power. The pundits will always say you must use a 'leisure this...' or a gel sealed that.....' etc, but I've never found it so.
Exactly what I do on my Centaur.

I have enlarged the domestic battery box to take 2X100 Amp hr leisure batteries to give more juice.

Engine battery, any decent sized diesel car battery is good enough.

The alternator charges both batteries even if the 1/2/both/off switch is set to anything but off.
Bob.
Centaur now sold. Boating from Tarbert.
TyroSailor
Posts: 630
Joined: Mon May 18, 2015 6:48 pm
Anti Spam measure: No
AntiSpam Text: Westerly

Re: What battery for engine starting?

Post by TyroSailor »

They're pretty well sealed then :)
Experience: That which would have been most useful five minutes before you acquired it.

Steve
Tyro (Centaur 1361)
at Southampton
Post Reply