Battery Question

[Fascadale]

Hi

Boat out of water, standing outside. Three hours drive from home.
Short term (for the day) mains electricity available.

Would it do the batteries any good to connect up a trickle charger for four or five hours on monthly visit to boat?

If I connected the charger to the terminals on one of the batteries and then put the switch to 1+2 would they both benefit ?

If this is not a good idea then, other than taking the batteries home, is there another way of maintaining the charge?

Thanks

 

[Ruffles]

FWIW I've never charged my batteries (2*110Ah) while boat is ashore and never had any problems. Were they fully charged when the boat came out?

 

[Fascadale]

Hi Ruffles

Yes, they were: boat came out mid October.

Cheers

 

[wigen]

If the batteries is fully charged there isn't any problems leaving the batteries in the boat as long as the batteries is 100% clean around the terminals. Just a little dirt might discharge the battery. A fully charged battery can resist up to minus 70 degree centigrade (or should I sat "down to"). But charging the batteries a couple of times during the winter is always a good idea; even the humidity can discharge the batteries.

NEVER mix batteries on the same circuit unless they are 100% equal (same brand, type, size; same characteristics). If one of Ruffles 110Ah batteries dies he has to replace both of them if he still wants 220Ah!!! If Ruffles just replace one of them he might end up with ~120Ah.

 

[jimbaerselman]

Yes, it'll help.

Trickle charger?

If it's a 13.6v output, it won't help very much, but a little is better than nothing for keeping the battery awake. And you could leave it attached for a week without damaging the battery, though in that case I'd recommend completely disconnecting your batteries from the boat's electrics, and paralleling them with a pair of starter jump cables or similar. Make sure all your conections are sound and very secure - no sparks or high resistance connections permissible! And polarity right.

If it's a 14.4v output, better not leave it attached for a week, you're likely to gas off too much water. But a 5 hour session will be much more efective.

If it's a smart charger which detects the battery charge state and switches charging voltages as required, leave it on. But disconnect the boat's system except when you're on board and needing lights, or whatever.

You'll find loads more super information about batteries on William Darden's brilliant site.

 

[pampas]

IMHO YES to both of you questions

 

[Rooster]

My boat's been out for a couple of months. Have brought all 3 batteries home to give them each a 4 or 5 hour charge once a week to keep them topped up. Just for peace of mind as it would be expensive to replace all 3 at once if they were damaged.

R

 

[ebbtide]

[ QUOTE ]
once a week to keep them topped up.

[/ QUOTE ]

Isn't that the worst thing you can do? When I was younger - and fitter - I brought them home and DISCHARGED them with a bulb across, THEN trickle-charged until full. Something about batteries liking to be USED??

Nowadays? - don't ask! You won't see me lugging the darn things along the pontoon, that's for sure. And the Avon doesn't come home to live partially inflated in the loft either!

 

[wigen]

[ QUOTE ]
Something about batteries liking to be USED??

[/ QUOTE ]

That's a tall story.

 

[William_H]

In my early electronics experience it was the done thing to discharge emergency standy batteries occasionally. It is still done with NiCad batteries but now it seems the wisdom is to not discharge beyond 50%.

Things and opinions do change.

Yes give the batteries a burst of charge once per month. You might want more than a trickle charger for a few hours charge. You need a charger with an ampmeter so you know what is going in. A charge of 10% of capacity once per month might seem appropriate.

It has been suggested that just leaving them to slowly discharge won't hurt. Burt really you just don't know if it does any long term harm. The suggestion of many is that it will. olewill

 

[PeterGibbs]

All charging is to the benefit of the batteries. When you combine them via the selector switch the weaker battery will always take precedence - is this what you want? I would swing the charge between the two on each visit.

PWG

 

[Fascadale]

Thank you for the thoughtful replies