Got shorepower and battery charger - leave it on all the time?

CaptainBob

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As per subject. Should I leave my battery charger on all the time? If I switch it off and then on again a short time later, it switches to "Absoroption" mode and runs the batts at about 14.8v, then goes back to "Float" after a short time.

I should mention that I have a Rutland 913 wind thingy and HRDX controller also.
 
There is the problem of anode decay as well, particularly if a boat nearby is on a different phase. I leave my boat unplugged most of the time just plugging in to top up once a month or so.
 
Don't leave your shore power on all the time is my advice.

As has been mentioned your anodes will probably suffer and quite possibly your batteries too, (depending on how sophisticated your battery charger is).

A 913 will keep your batteries fully charged and is virtually silent in operation, so you shouldn't have any problems with neighbours or the marina. I have found this to be the best option. On returning to the boat after several months the batteries were fully charged and no sign of electrolyte loss, which had been a problem with leaving the shore power charger on.
 
Agree with the other posts.

Just charge or top up when on the boat. During the week or fortnight away, the battery will just rest without any harm at all.

I have a similar set up except that I use a 20W solar panel, which keeps the battery in good nick whilst I am away.

If the Wind power genny is producing many amps in a windy week, I would consider stopping that as well.

I am sure resting the battery is part of its 'natural' cycle, and will help to prolong battery life.

(Not an expert just a user!!)
 
Many times I've illustrated my set-up that sits ticking away day after day after day.
I used it when boat was in UK and I was 3 hrs plane flight away, I use same now boat is at home here.

Maplins charge splitter : http://www.maplin.co.uk/Module.aspx?ModuleNo=37767&TabID=1&WorldID=&doy=6m1 there is now an updated version from Kemo.

This is fed from a bog standard car charger of about 4 - 6A capability controlled by a mechanical timer set to provide mains electric for a few hours each day.... with 1 day a week rest.
a) it prevents overcharge
b) it keeps batterys right up
c) simple and cheap.

Used it for about 4 years now and no complaints.

The point about anode depletion is only valid if you bond mains earths etc. to them ... - I don't. There are too many schools of thought about electrics on boats that none agree on 1 system and 1 system only. But common is that they all show some disadvantages in each set-up. My opinion is my boat is not bonded to earth nor across various items keeping them isolated. I have had no corrosion evidence after present boats 10 yrs ownership to support bonding.

Of course now some 'expert' will show where I'm totally insane !! /forums/images/graemlins/laugh.gif
 
I agree with you basically.

When I gave up building mains chargers back in the 1990's, to much agro, we had a maintanance phase. This would turn the charger off when power demand was low, and the battery charged. It then turned back on the mains as required to produce a charge cycle based on battery state. This resulted in running the charger about 30 sec every 1 or 2 hours. As the charge pulse was to the high charge voltage it stopped sulphation, and if there was any broke it down.

We used to do a controller that went in your mains feed to the standard charger, produced a maintanance cycle when you left the boat. So you had minimum mains on, de-sulphation charge, a counter voltage phase to clean plates, and a fully charged battery.

So your system is not perfect, but it does makes a workable solution, though if you have a bi-directional VSR, you save the Maplin bit.

Brian
 
I would have thought that the wind charger, putting in 20 amps av per day, is adequate for battery maintenance if there is no significant load on the batteries when you're away.

Any load beyond that and you may well want to stay shore connected, in which case disable the wind gen and save its bearings - replacements cost more than the little power taken from on shore, esepcially if the shore supply is bulk charged, not by the amp/hr.

My boat is ashore all winter and connected continuously through a smart charger. Works a treat and costs virtually nothing. Not the same if you're afloat, I realise.

PWG
 
Thanks and I respect your knowledge in this field.

When I say my boat is not bonded - I am referring to the leads connecting shaft, negatives of electrics, VHF etc.

I do have mains electric earthed via the cable system.
 
Sorry to say, I use a little 4 amp charger that was on the boat when I bought it. Just plug in when I'm down, wind gen runs other time.

Keep saying I'll build me a proper charger, trouble is I never have the time.

Brian
 
I should have mentioned I'm spending a LOT of time aboard the boat, and so am using some 12v systems regularly, and shore-power is on all the time anyway (I'm aboard now, working on my laptop).

Does that change the situation?
 
My system stays connected at all times - even when sailing. So when I moor up - it is already to start duty again once mains plug is connected.
As to "smart" charger - that will not work with maplins splitter as I found, the splitter seems to confuse the chargers sensor circuitry.
 
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