New Batteries

[Sharkbyte]

It appears that the batteries in my boat are due for retirement and I am after any suggestions about suitable replacements.

 

Currently (no pun intended) I have one of 110ah and a second of 90ah but feel that these are probably overgunning it. Not only do they weigh a considerable amount but I never really scratched the surface in terms of the charge they hold. I run the gps and ff all day, an anchor light and periodically a cabin light at night, yet when they were new, barely any voltage drop was noticed even after sustained periods at anchor.

 

I am currently considering replacing them with a pair of 45 or 60ah's and fitting a battery conditioning system with the money saved over the cost of a pair of 110ah's.

 

One thing that I have wondered in the past, are batteries of 110ah+ putting too much strain on the charging coil in an average outboard engine (50/70hp)?

[Toerag]

I believe a bigger battery will not exert any undue pressure on coils or any other equipment. More AH simply means it will last longer, not that it will produce any more current. I don't know how many AH my batteries are, but by running my electronics and baitwell pump for 3 long drifts on one battery I can flatten it to the point where there's not enough juice to crank the engine (150hp diesel).

[Chris Goddard]

I believe a bigger battery will not exert any undue pressure on coils or any other equipment. More AH simply means it will last longer, not that it will produce any more current. I don't know how many AH my batteries are, but by running my electronics and baitwell pump for 3 long drifts on one battery I can flatten it to the point where there's not enough juice to crank the engine (150hp diesel).

 

Spot on with your thought RE: Current. Current or ammperes are only produced through an increased load.

[M.P]

It appears that the batteries in my boat are due for retirement and I am after any suggestions about suitable replacements.

 

Currently (no pun intended) I have one of 110ah and a second of 90ah but feel that these are probably overgunning it. Not only do they weigh a considerable amount but I never really scratched the surface in terms of the charge they hold. I run the gps and ff all day, an anchor light and periodically a cabin light at night, yet when they were new, barely any voltage drop was noticed even after sustained periods at anchor.

 

I am currently considering replacing them with a pair of 45 or 60ah's and fitting a battery conditioning system with the money saved over the cost of a pair of 110ah's.

 

One thing that I have wondered in the past, are batteries of 110ah+ putting too much strain on the charging coil in an average outboard engine (50/70hp)?

 

 

 

Sharkbyte, check out Debbage marina, they get hold of 110ah marine batteries for less then £50.00.

 

 

E-mail : debyacht@onet.co.uk

 

Phone : 01473 601169 and 07774 694226.

 

As others have said, size of battery won't effect your charging rate.

[Steve Coppolo]

One thing that I have wondered in the past, are batteries of 110ah+ putting too much strain on the charging coil in an average outboard engine (50/70hp)?

 

What you don't want Wayne, is charge being built up with nowhere to go. If it can't get out it'll cook the stator among other things.

[sam-cox]

I think there is some maths to do hear. Maybe the outboard alternator charging out put nedds to match the amount of amps that the battery can be charged at.

[Sharkbyte]

Thanks for the input guys, i've just checked up on Yamaha specs and they recommend a min of 70ah batteries on all their electric start outboards, so a couple of micks 110ah marines it is. Cheers for the details mate, sounds a pretty fair price to me.

 

Point taken on the bigger batteries putting no uneccessary strain on the charge coil.

 

One thing I did overlook is the high output deck light I have, but not yet installed. I'm going to need it when landing the 50lb+ Stingray Sam's promised to put me over later in the year. Wouldn't want to loose sight of that tail at a critical moment because a 45ah battery ran out of steam.

 

Steve, I will be checking the charge coil and rectifier against factory specs as a precaution. I had found that when the batteries dropped by 0.5-1v I couldn't get them back up again even after a 45 minute steam. To be honest I recon this is down to the batteries being past their best as that last volt or so disappears within minutes of any load being placed on them now and is only able to be restored on a home charger with all electrics shut off.

 

I'm definately going to buy a battery conditioner with the replacement batteries, I've found some nice ones made by ctek which can be permanent installed an permanently plugged in when returning home.

 

Ctek Battery Conditioners

 

cheers guys.

[Steve Coppolo]

I use two batteries too. One is purely for starting the engine, the other runs the electrics. I've had to charge the electrics one several times, but I've never had to charge the engine one. I could swap them around through the year to keep a good charge in them both, but I can't be bothered with the small amount of hassle it would be!

 

I've got a DVA peak reading multi meter if you want to borrow it to check your charge coil. Only one condition, if you fry it you replace it! It was very expensive!

 

The rectifier can be checked with a regular multi meter.

Edited January 24, 2006 by Steve Coppolo

[Sharkbyte]

I've just remembered that livebait tank thats to be installed when I can be bothered and the 12v fridge I have but has never been used. Mick, could they do me a pair of 200ah's?

 

I've got a DVA peak reading multi meter if you want to borrow it to check your charge coil. Only one condition, if you fry it you replace it! It was very expensive!

 

Gulp... It's ok Steve, I'll risk frying my basic ammeter. Ta anyway mate.

[Stoaty]

You should find all the information you need here

 

12 Volt Handbook

 

Alternator Handbook