Have I Killed My Batteries ?

[torgersende]

Bought a Passport 43 in September. Laying up for the winter, I plugged into the shore power December 1st, with a plan to run the inverter to charge the Batts on the first of the month keeping them topped up over the winter. Yesterday, checked the batts (Heart Interface) and both batteries read down approximately -150 AH, with the "low battery" warning flashing.

I then checked the panel, and it reads something akin to: "reverse polarity, disconnect from shore power immediately"...

I unplugged from the shore power, found a new outlet that does not read "Reverse polarity...", and attempted to charge batts overnight. Of the 2 banks, one came up to -118 AH, (still flashing "Low battery"), the other did not come up at all.

Have I just killed $3000 worth of batteries, and is the yacht club at all liable for having reverse polarity at the outlets?

2 more pieces of information:
Boat was plugged into the mains during December, but the Batt switches were in OFF position, as was the AC switch on the Panel...

[CarlF]

It's as likely to be your Hearst interface as the batteries.

Measure the voltage after unplugging (at least 30 minutes - longer is more accurate but you will be reasonably close). A mostly discharged battery will be less than 12.0v. A full battery will be about 12.8v.

With this information, you can make a plan.

Carl

[CharlieJ]

To clarify what CarlF said: use a digital multi-meter (DMM) and, with the inverter/charger turned off, take voltage readings of the batteries at the battery posts. Report back with the readings and one of us will be able to answer the $3000 part of your question.

While you are on your boat:
What model inverter/charger do you have installed? Do you have LED indicator lights on your circuit breaker panel?

Charlie

[torgersende]

Charlie,
The inverter/charger is: Freedom 20 (2KW). No lights on the panel, other than an indicator on each breaker to identify those that are currently active.

There is an analog gauge to show battery and panel voltage.

I will perform the tests with the DMM after work. Should I disconnect each of the batteries, in order to test them individually? (after disconnecting shore power and ensuring the inverter/charger is off)

[capn_billl]

I would. You can test the bank voltage, but checking each battery will give you the most information as to where you stand.

[donradcliffe]

The reverse polarity indicator means everything will still work, but you have a dangerous situation-it is possible to get an electric shock. Where are you located, and what type pf plug do you have for the dock power? If you have a plug with 3 pins (can't be plugged in backwards, talk to the marina about their wiring polarity. The reverse polarity has nothing to do with your battery problems.

If you left the mains plugged in but the AC switch off and the battery switch off, the battery charger was not working, and the batteries got discharged. Either the batteries self-discharge or you have some load on them which bypasses the battery switch. Wet cell batteries could have discharged 50% or more in a month, but gels or AGM's have a lower self-discharge rate. Do you know what kind of batteries you have??

I would charge the batteries, then disconnect them and let them sit for at least 12 hours, then test voltages. How many batteries are there, and are they connected in parallel? When you reconnect them, leave the battery switches off, and measure them again--any sparks when reconnecting or a lower voltage after reconnecting indicates a possible load which is not going through the switches.

Have fun--did you replace the batteries after you bought the boat??

[CarlF]

I'm guessing that you are fairly new to boat electric systems. For safety, I'd proceed in a conservative fashion. For one thing, batteries and inverters (even when off) can pack a whollop. You can get hurt even at 12v. I'd rather not have you sticking your hands into a battery compartment or disconnecting hot cables until you know more. Start with that analog voltage gauge on the panel (you might need to turn on the battery switch).

The most happy possibility that you can quickly confirm or rule out is that your battery bank is fully charged (eg. 12.8v or close). It's quite possible that the Heart monitor has not been reset for a long time. The Heart doesn't know how many amps hours are in your battery. It just keeps track of power going in and out over time and keeps a running total. It's quite normal for them to be be way off if not periodically reset to zero when the battery is known to be fully charged.

Carl

[Seahunter]

The answer is NO.
1st check water in each cell. Top up if necessary.
I can run you through a reset of your Heart, but you're better to call Heart directly. They have a GREAT support system and will walk you through it. They are of course Xantrex now. Their # 1-800-670-0707. Make sure you have model and serial numbers.

[capn_billl]

In retrospect after reading the post in datail I think I can guess what happened. It is unlikely that the wiring changed on your dock over the winter. More likely a power surge or outage, or lightening strike. The Heart is most likely not giving good information and needs reset, see SeaHunter above. The reverse polarity alarm is usually just a check between ground and neutral, or between the two phases for 208v. a bad breaker, or fuse can give a false alarm. The above posters are correct the reverse phase has nothing to do with your DC (battery bank), except it probably kicked off the battery charger and may have confused it. The safest thing to do is to get a qualified person to check the whole system from the top.