Battery charging

[MUS]

I have a 22ft boat with nothing more than a depth sounder, VHF, interior light and a tiller pilot on board, all powered by a single battery. The engine is any out-board with no charging facility. I therefore am trying to find the best/cheapest/easiest way of charging up the battery.

Can some one tell me what the difference between a charger bought from a chandlers for £100+ and a car battery charger for £10?

Will it be worth me buying a solar/wind charger to avoid the hassel of removing the battery constantly, and what size will I need?

 

[Guest]

I have Hurley 22 with similar set up with heavy duty car battery. At first I used car to charge up on way to boat then found add in paper for solar trickle charger that keeps it charged between visits (aprox 2 weeks). I believe they can be found at Maplins etc.

 

[peterg]

You could try an 'Optimate' or similar battery charger which is used for seldom used motorbikes and the like as you can leave it on all the time and it monitors the battery and only charges it when it needs to be - these are available from Halfords and most motorcycle shops at around £45.

I have used these on motorbikes and boats for many years now and they work brilliantly.

 

[andyball]

the cheap chargers will almost certainly be unregulated...that is to say that eventually...once the battery is fully charged,they may over-charge it, say to 15 or 16Volts....even with a largeish battery. This can damage the battery

The optimate and others, are cheap(ish) but do regulate.

Presumably the boat is away from power,since you mention removing the battery to charge it: the solar/wind chargers would work...probably the smallest available would suffice.

Some o/b's can have charging kits retro-fitted.

 

[oldharry]

Go to Argos and for £20 get a Gunson Automatic charger, which operates to all intents and purposes like a very much more expensive pulse charger, and brings the battery up to full charge. It also has a 'float' switch' which allows you to leave it permanently connected (like during the winter lay up) without risk of damage. Excellent value.

Cheaper unregulated chargers only bring the battery up to about 90% charge in 24 hours, but if left on for extended periods will damage the battery.

Dont forget the £100 charger from the chandlers will have had an incredibly expensive sticker put on it, saying 'marine', and which allows the supplier and chandler to put anything up to a 50% extra mark up on the price...

True pulse chargers have quite sophisticated electronic control circuitry which senses the battery's state of charge, and allows the charger to bring it up to 100% charge, while the cheapos just pump out around 15 - 20 volts and hope that the battery internal resistance will hold the voltage down to a level that will not cause too much damage in the first 24 hours!

 

[Guest]

Thanks oldharry - I didn't know Argos had a good one at the moment! I have one I bought 2-3 years ago made by Bradex and that is a fully automatic with float but at £20 a second one would be great!

Solar panels are good especially as you don't really take too much out ... you didn't mention starting did you? You can go to Maplins [as suggested] but don't forget to buy a regulator to go with it - otherwise the battery voltage will rise and rise and the battery will be useless! There is a model I have noticed in various car ads which plugs into a cigar lighter socket and is quite compact and my local chandler now stocks them at a similar price for the small one which is about £25-30 and I think its output is around 0.3A which is OK for small usage? They do have other larger ones eg. 1A which costs £150 [marine added tax there I think?]

 

[MUS]

Thanks for the advice. Unfortunately Argos don't seem to stock Gunson Automatic chargers anymore. Is there anything similar anywhere?