Electrical Mystery

[ad_astra]

So I recently became the owner of a 1975 Tartan 27 in pretty decent shape. The boat did fine on the test sail and passed the electrical portion of the survey with flying colors. The test sail was two weeks ago and the boat was last run ten days ago, and has been plugged into shore power since then. Ten days ago the engine was serviced just before it last sailed.

Today I came to see the boat for the first time as the owner and found a substantial amount of water in the bilge (well more than normal) and also discovered that the manual pump does not appear to be functioning. After some exercise involving a portable bailing pump and a bucket, the bilge is now at a much more reasonable level.

The house battery has a whopping charge of millivolts, and the starter battery has a charge of 2.6 volts, so the reason the bilge hasn't been pumped is clearly electrical. Everything was turned off when I arrived..... What could possibly cause two working batteries to die in 10 days? Also, I'm pretty sure I know the answer to this question, but at that level of discharge, they need to be replaced for sure, right?

[ad_astra]

Just one other potentially useful bit of information... the inverter status lights don't light up when I plug it in.... so the inverter might be dead.... but the batteries shouldn't be dead 10ish days of sitting a marina.... hmmm.... could some sort of a short kill both the inverter and batteries?

Ah well, more will reveal itself tomorrow when it is light enough I can see what the wiring is doing....

[Rising Star]

ad astra,

You say it was plugged into shore power and the batteries are dead - check your battery charger. It may have fried the batteries.

[Stillraining]

Kind of unusual having an inverter on a 27 footer..are you sure that's not your charger..if so you found your problem more them likely...and yes it is VERY easy to drain batteries over 10 days...shoot a stuck bilge pump float can do it in less then 2.

[ad_astra]

Yes, by inverter I actually meant charger. And seeing as how the the side of the charger I couldn't see at night seems to have exploded, it's a fair bet that's the culprit. I'll get my camera and attach a picture when I get a chance.

While one of the batteries could be drained by a stuck switch or whatnot, the only thing that both of them are connected to is the charger, so I think that's the principal suspect.

[Fishspearit]

You need to start with fresh batteries and go from there.(and probably a new charger too, from the way you describe it.) If the batteries were shot from the beginning, the charger may have burnt up trying to charge dead batteries. Just a guess, but I'll bet if you pull the caps on those batteries you'll see dry plates because no one has watered them for the whole summer.