Batteries

[Little Sam]

Bump.

I thought it was normal on forums to search an already queried question rather than start new threads !?
So theres mine above if anyone is out there.....

 

[Stemar]

Hi.

I am also fitting out the batteries and electrics side of my little boat. I already have an engine starter battery but no liesure batteries.
I have 2 good quality 20 W solar panels and a Rutland 504 with a dual solar wind charger regulator from Merlec rutland.

I was wondering what would be the best battery set up for when i get the leisure batteries and how to wire them up considering i'll be spending long periods on the boat.

Hers the equipment that will be sucking on the battery's.

Standard Horizon fixed VHF AIS reciever radio GX2100
"" "" CPN 700i plotter that will also be music player internet access play the odd movie.
Nav lights
Internal Leds lights etc.

The odd use of a hair dryer for the Missus with an inverter.

Recommendations please ....

The hair dryer's the killer, but it does only run for short periods (presumably....) I'd be inclined to retrict it to when the engine's running - if you dare!

My feeling (other opinions are available and may be just as valid ) is to have a relatively small starting battery, mine's a second hand 35AH car battery that's in its 6th year on the boat, and as big a domestic set as you can squeeze in.

The starter battery is ONLY used to start the engine and, apart from the isolator switch is hard wired to the alternator. The domestic battery does everything else and is charged via a relay energised by the wire that goes from the charge warning light to the alternator, so it only kicks in when the engine's running. A voltage sensitive relay is ideal, but I had an ordinary one in my bits box, so I fitted it until I could get a VSR. It's still there.

I'm fitting 40w of solar panels this winter, with a dual battery controller. This will charge the engine battery until it's full, then turn its attention to the domestic. That way I'm pretty sure the starter's going to spin when I want it to! Long term, I expect to get as much charge out of 40w of solar panels and the controller that'll leave me change from £100 than a wind gen that costs five times as much, only gives a worthwhile charge when SWMBO thinks it's too windy to be out, is noisy and, in the only practicable place to mount it on Jissel, is likely to rearange my skull if I'm careless getting on board from my dinghy.

There's a 0-1-2-both switch to connect the batteries if necessary. It stays off when I'm not using the engine. 1 connects the starter battery to the engine for normal use, 2 connects the domestic to the engine in case of a problem with the starter battery and both connects them in parallel. So far, the only use I found for both was when the domestic battery was completly flat, so I isolated it and used the starter battery for a few minutes of light.

I could let you have a circuit diagram for the split charging. PM me if you're interested or have any other questions.

 

[BAtoo]

+1

If you don't get the individual batteries in a bank correctly connected (balanced length of connectors and wired in the right order) then one is always a little over-used and dies first.

 

[KellysEye]

Sorry, I meant T105, this is caused by gin with the cornflakes.

 

[johnphilip]

Seems AMPle

I have 4 domestic 110's, 1 fridge 110, and 1 engine 90 fast crank. All works for me.

Does the boat float much lower with that lot?

 

[pvb]

Does the boat float much lower with that lot?

Batteries aren't that heavy. I've now got 7 x 105Ah batteries tucked away under the aft bunks, and there's been virtually no discernable difference to the trim.