A few mAmps going free

[pelissima]

Hi to all,
to launch my new digital multimeter, I set it to measure mAmps, I disconnected the positive pole of my services (3x100), closed all switches on panels, and putting the probes on the plus pole and feeding open line I measured 38mAmps and 10 Volts. Do the forumites believe I should start tracing around (an 84 First 38), or just wait for the number to grow first?
Fair winds to all
George

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[cliff]

Before you go hacking the loom to find the leakage, is there anything hard wired ie permenantly on such as a NAVTEX? or VHF? or a clock? or ......?

Wait a minute, I just read your post again - You CLOSED all the switches on the panel - oops. If you did that you have switched everything on and if you then put your meter across the pos term to pos lead you should have blown the cr@p out of the meter unless it is one of these auto ranging jobbies.

Open the switches (turn everything off) and try again. Might have knackered the meter though.

I must admit I am now a little confused.


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[pelissima]

Ooops, sorry for the confusion, I meant Opened all swiches-was translating from native language. And no other instrument connected..
Anyway, is the number high enough for worry?
Rgds
George

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[AlexL]

you may well be measuring a backup battery or capacitor in something which is hardwired to the system. On my boat with all switches off my bilge pump and the stereo are still live. your boat may have a couple of things like this wired direct to the battery.

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[robp]

Having visibly checked that there is absolutely nothing connected to batteries but the feed to battery switches you would start to trace by disconnecting from the switch onwards and re-checking at each isolated point. It could well be simple leakage across damp plastic. By simple maths assuming you left it, it would take 1,842 hours to completely discharge a 70 AH battery at that rate!

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[cliff]

If you opened all switches then logically the leakage must be between the pos terminal and the electrical panel feed assuming there are no "extras" hard wired.

First place I would look is the starter motor solonoid second would be the alternator then the electrical switch panel itself.

Easy to check the solonoid, undo the nut and remove the heavy feed lead (starter cable) keeping all other leads that are connected to the same terminal connected to the lead (alternator and electrical panel feed). If leakage disappears or drops then the solonoid is leaking (damp?) Give it a good clean and dry it. If the problem persists, disconnect the alternator lead (if fitted to the starter solonoid) and so on until you find the problem. If disconnecting the alternator charge lead cures the problem again clean and dry as far as possible and if still leakage take a lead direct from the alternator output lead and connect that through your mater to the pos on thebatery. that will tell you if it is the alternator or not. I am afraid it is a process of elimination, one item at a time.

When disconnecting leads make sure you know where they go back on.

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[snowleopard]

apart from leakage across insulators the most likely cause is something in 'standby' mode. for example a car stereo has 2 power inputs, one wired permanently on to maintain the programming.

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[pelissima]

Apologies again.., It was the led showing battery status. Once defusing it, no leak.
Thank you all for usefull tips.


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[cliff]

"something hard wired? well, yes.

Glad you found it, now why not wire it up to the services side of the battery isolation / selector switch then you will see when you have forgotton to isolate the batteries before leaving the boat and also switch it off when you do. I fitted one because I was always forgetting to turn the batteries off and it was a good indication when SHMBO was running the hair drier of the inverter for too log! - little yellow light coming on!

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Just one more time!