Electric current drain

[DavidWR]

I have a 1 year old boat with a single (110 Ah) battery. It has a hardwired battery charger that works off the shore power, and an alternator on the engine.

I mainly use the boat at weekends, and when I get to the boat on a Sat, having left it on Sun night, the battery is almost invariably low, not having enough charge to turn the engine. This problem is fixed by putting the battery on charge for about 30mins. I know this problem could be eliminated by leaving the shore power connected, but I don't want to do that.

I have measured the drain current on the battery with everything off, and the drain is around 200mA. This sounds high to me - what does the panel think?

The only thing on is a CO alarm and the bilge pumps - none of which can be switched off while I'm away, even if I wanted to.

Does this sound like I have some other problem that is causing the current drain, or is this what people generally live with?

Any ideas?

Dave.

 

[cjrvernon]

i have the same set up as you
i leave the shore power on all the time to keep the batterys charged
as i leave the 12 volt fridge going all the time

and never get a problem
batterys do discharge over a time on there own
regards
christian

 

[muckypup]

I get a drain of about 300ma with bilge pumps and gas alarms. So your 200ma is normal. If you are not on shorepower, you will have to turn off your 12v at the isolator switch. You could also invest in a solar panel to keep your batteries topped up.

Steve

 

[savageseadog]

I think the only thing to do is have a close look at the manuals for the still connected items and see what the standby current or disconnect them till you find what's taking it. The 200mA is a significant drain and will see off any battery if left long enough.

You should rewire the CO alarm so that it switches off, as there is no need for it to be on while you're not there.

It's possible that the current could be going through some metalwork into the sea and back through the stern gear, seen any good corrosion recently?

 

[DavidWR]

Thanks for the comments, chaps. It sounds like this behaviour is pretty-much as expected. I won't waste time trying to track down a non-existent problem in that case, and I'll leave the shore power on if I leave it more than a few days.

 

[DavidJ]

My CO detector (Pilot) takes 90mA so you are a bit over. When you're not on the boat the detector has no purpose really so you could find a way to rewire it from the 'other side' of the main switch. Personnally I would install a second battery with a simple switch so you can switch charging from one to the other. That way you safeguard yourself from depleating the battery when out anchored up in a bay with fridge on and not being able to restart to get home (It happened to me with a previous boat fitted with single battery)
Depending on how much you want to spend but there are numerous battery management systems around which will look after a twin battery setup automatically.

 

[kimhollamby]

The bilge pumps should draw zero current unless they are the type that auto switch every couple of minutes...it's not really healthy to have your battery drop that much every time you leave the boat so I would not leave it if I were you.

If you do detect any current draw on the bilge pumps then check you have nothing live dangling in bilge water...

 

[savageseadog]

Try to take note of what's been said. It shouldn't be drawing that much, I really suggest you find out what's going on.

 

[Petrolia]

I agree with David.

One of the first things I did after buying my single batteried Hardy 24 was fit a second battery.

 

[ColinHuggins]

Off at a tangent, BUT . .

My primary bilge pump is on always but via a sensor, So the boat could eventually sink with the pump having worked until the battery died.

What's the logic of that?

 

[[2068]]

The logic is that in the case of a small leak, the pump might be able keep going long enough to keep the boat afloat until your next visit.

In the case of a larger leak over a longer period of time, you're right, the boat will sink with a flat battery.

dv.

 

[boatone]

In November 2004 I 'floated' (pardon the pun) an idea for a two tier float switch or switches
[ QUOTE ]
Been a bit of banter with rumtigger re floatswitches but actually got me into some serious thinking re this whole issue.

Bilge pumps can be activated automatically or manually for two main reasons....
1. Routine removal of minor water....sterntube drip etc
2. In anger cos exceptional inflow of water in an emergency

If a float switch is fitted they will operate automatically and in situation 1 cut off again. Howver in situation 2 the bilge pump may be unable to cope with the inflow and the boat will be at risk of sinking. In both cases without some sort of additional alarm you may be unaware that the bilge pump has actually cut in. If the boat is in the marina and connected to shore power the pump may operate indefinitely but on battery power will eventually run down the batteries and stop.

Had a situation in my marina recently where by pure chance someone noticed a neighbours boat low in water and could hear pump running and just managed to avoid sinking due to ruptured skin fitting.

So heres an idea for debate.............
If boat usually dry inside and only reason float switch likely to trigger because of emergency water ingress then have audible alarm also connected to switch so goes off when pump triggered. If float switch triggers under normal circumstances then fit secondary float switch at higher level which will trigger audio alarm if water reaches that level. Either way audio alarm loud enough to attract attention whether on board or not.

Simple idea but I think it has merit.....What say you.....?


[/ QUOTE ] SEE full thread HERE
I think hlb will confirm that he did indeed set up such a system and it sort of saved the day one night!

 

[Alrob]

DAVE

HAD THE SAME EXACT SAME PROBLEM ON MY NEW BAYLINER 285 MESSED ABOUT FOR WEEKS WITH BATTERIES THAT i HAD LEFT IN OVER THE WINTER WITHOUT RECHARGING.

REMEDY = 2 NEW 110 AMP DEEP CYCLE BATTERIES PROBLEM NOW SOLVED, I CAN NOW LEAVE ON FOR WEEKS WITHOUT ANY PROBLEM (DONT LEAVE FRIDGE ON THOUGH ITS VERY THIRSTY)

I ALSO THINK THE BATTERIES THAT WERE SUPPLIED BY DEALER WERE CRAP

 

[harvey]

Please don't shout Old Chap

 

[thefatlady]

[ QUOTE ]
check you have nothing live dangling in bilge water...

[/ QUOTE ]
/forums/images/graemlins/shocked.gif /forums/images/graemlins/shocked.gif /forums/images/graemlins/shocked.gif

 

[thefatlady]

My Sunseeker as standard had two aft bilge pumps,each with its own switch. If the (slightly) higher one cut in (has been known in very heavy weather) an alarm sounded at the helm.

 

[neale]

Another point worth considering: Some battery chargers, if left connected but turned off, actually drain current. Not usually alot, but it could be part of the problem. Disconnect each item in turn and take new readings, you will then see which is the biggest culprit or if there is another issue that needs looking into.

 

[kimhollamby]

Some Sea Rays...

Have low and high level bilge pumps in the same bilge, similar kind of idea, with the smaller, lower one there to deal with dribbles and the higher one to provide a bit more grunt for emergencies. This would work really well for boats with bilge sumps which, all too often, get fitted with a Christmas cracker bilge pump on the basis that it is all that will fit.