Mercury Outboard general discussion
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Toby Hall
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Joined: Tue Feb 01, 2011 12:13 am


Post by Toby Hall »

What would you guys recommend to use for a starter battery? For a Mark55E or say a Merc 300? Right now, I'm using basically a car battery. Seems like a little overkill, not to mention heavy. [usa.gif] [canada.gif] [drinkingcheers.gif]
The stuff you can't see - That's what's important.
dave bernard
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Re: Battery

Post by dave bernard »

If you want light weight lithium ion BUT EXPENSIVE !!!!!!!!!!!!
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Re: Battery

Post by 58woody »

I use AGM Marine batteries, maybe a bit heavy but always work.
Thats what I use for my Mark 58 on a 14 foot Ranger III.
Mark 6, 1956 Mark 55 & 55E, 1959 Mark 55A, 1958 Mark 58, 1960 Merc 300, 1961 Merc 500, 1961 Merc 700, 1964 Merc 1000 Bradford, Ontario, Canada

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Re: Battery

Post by Stobl »

Motorcycle/ small engine batteries work perfectly fine for that.

YTX20L-BS, YTZ14S, and ML35-12 are ones i have on my hand-dandy list for boats and jetskis that I have. the ML35 is a little bigger (more like riding lawnmower size) than the other two if you need some reserve power for off-motor "stuff"
Blake- Southern MD
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Re: Battery

Post by Yellowjacket »

You have to be careful with small batteries on these older motors. The reason is that these motors don't have a voltage regulator they just have a rectifier to make the AC coming off of the alternator into DC. As a result, there isn't any charging control and at high engine speed the charging current can get too high for a small battery. A larger battery is fine and you likely won't overcharge it, but a small garden tractor battery could get overcharged and start to gas if you run it for too long at high power. If you don't run at high rpm for long periods you're likely fine but it's something to be aware of. If you want to fix it you can add the voltage regulator from a Briggs and Stratton 15 amp unit that you can get on EBay or Amazon for less than $20.
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Re: Battery

Post by Fingerlakeskid »

Trying to lighten the boat for a little more speed? Must be I made you nervous with my new prop and some transom shims.
Stan Augustine

Mark 30 tiller, (2)Mark 55, Mark 58A (2)Merc 200 FGS, Merc 450, Merc 500. 1950 CZT Penn Yan Swift, 1957 Alumacraft FD, 1985 Larson Senza w/Merc 1150,
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Re: Battery

Post by ctpdsr »

I don't use electric start on my vintage Mercs, but for my Boston Whaler fishing boat, this hybrid Deep Cycle/Starter battery has performed well. Marine construction is important. I actually "broke" a battery in my Hydro Stream old guy boat. These also hold a charge better vs. standard starting version.

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