Battery Discharge in 2 days

[Gypsy]

I have a 1998 Albin 28 and having electrical problems. When connected to shore power my shore power breaker is illuminated "reverse polarity". Whether connected to shore power or not, my "Charge Indicator" lamp on my panel is lit. If I disconnect the engine battery then the charge indicator lamp goes out.

I had a boat electrician look at the situation last autumn and he said the Charles Battery Charger was bad. I had it sent to Charles and they checked it over and found nothing wrong other than a bad fuse. It has been re-installed. During my troubleshooting I have taken a continuity check and found the following. From the positive (red) wire of the battery to the positive red wire of the battery charger I have continuity, as I should have. However, from the red wire of the battery to the negative (black) wire of the battery charger, it also shows a partial short.

If I leave the house and engine batteries connected, they both drain to zero within a couple of days. So, to avoid this, I have to disconnect the batteries after use. This occurs even with the battery switch in the off position.
Questions:
1. When the “Charge Indicator” lamp on my panel is lit, what does that actually mean?
2. Is there a way to troubleshoot a partial short?
3. Has anyone experienced this before, and if so, what was the cause?
4. Can anyone offer any suggestions?

I have attached some photos to help you see my situation. You will see the “Charge Indicator” lamp illuminated, the battery connections, and the shore power illuminated “reverse polarity”.

[Nancy]

Gypsy -

First, a caveat: I'm not an electrician. But we've seen our share of strange electrical problems.

Has this configuration ever worked properly? If so, my initial reaction is that one battery is bad, i.e. completely dead. If the batteries are wired in parallel, depending on how intelligent the battery charger is, the bad battery may be sucking all the current and never charges because it's dead. And the good battery never gets properly charged.

Are there separate leads from the charger to each battery? Depending on the technology of the charger, even that configuration might not reliably charge a good battery and ignore a dead one.

I would connect one battery to the charger and disconnect the other entirely. Charge the battery for 24 hours. After another 24 hours, take a voltage reading. It should be very close 12.6V. If it's below 12.2-12.4, the battery is dead. Swap the connection to the other battery and repeat the test.

Even if the voltage looks OK, there could be a dead cell. The cells can be checked with a hydrometer.

Just want to check the basics - I'm assuming the water level is good in both batteries. You wouldn't be the first person to overlook this.

That is almost the full extent of my electrical knowledge, but might give you an idea or two. I'm sure someone else will be along with more knowledge and additional suggestions.

[crowra]

Gypsy,

Nancy definitely has some good suggestions (and I am also not an electrician). I am very concerned about the reverse polarity. That means current from your hot ("black wire") could be running through the common ("white wire") or worse yet, through the ground wire (potentially fatal). That's usually on the shore power side and not on your boat. I recommend having your marina get an electrician to check your outlet(s) or if there is another outlet close enough that you can plug into, try that.

I looked at the DC side of your charger picture and there are two red wires and one black. Since one red connects to the positive terminal on your starting battery and the other to your house battery, is there a chance they are both connected to the starting battery? (I only say that because there is nothing connected to the positive terminal on your house battery.) Probably not but figured I would ask.

I don't know what the "Charge Indicator" light means other than maybe it is charging when lit? Your charger, upon sensing shore power, will "absorb charge" your batteries to 14.5 VDC. Generally after about four hours, output will drop to a float rate and maintain your batteries at 13.5-6 VDC. It doesn't look like there is anything that shows the voltage on either battery - only the amps used to charge the batteries. (The amps will drop to about 2 amps once the batteries are charged). Use a volt meter to check the charge.

I would start with Nancy's advice and make sure you have good batteries. That's the easiest thing to troubleshoot. Next turn the switches off everything (even disconnect the bilge pump(s)) and see if the batteries hold their charge. Then disconnect all red and black cables from the battery except the red and black wires from the charger to the battery (do this one battery at a time). Use a volt meter and see if the battery maintains a charge.

If none of that reveals a problem, now for the fun part of checking your electrical system for a short somewhere. Make sure your shore power is disconnected and the positive cables disconnected from your batteries and start testing for shorts or opens with an ohm meter. I recommend double-checking first with a volt meter to make sure there is NO current present.

Good luck!

[Halcyon]

Buy or borrow a hydrometer to check the cells of your batteries. The hydrometer will show if you have a dead cell right away.