Battery Problems

ALNims · Feb 15, 2015

hunter43sail said:
On my Passage 42 I have a Heart Freedom 30 charger/inverter and a Link 20.
It was install in 1998 and for the most part I have not had any problems.

For house batteries I have 2 8D's. I replaced them 3 years ago after getting about 8 years out of the old 8 d's. Now the batteries will not accept a charge. When I got to the boat the charge is about 10.5. After turning on the charger they go to 13.9 for about a hour. Then they go to float at 13.25 volts. If I turn the charger off everything is fine for about 15 minutes when the voltage drops back to 10.5. I have checked the cells and they look good except for one cell in each battery is on the low end of the good scale.

Any one have any ideas?

I would suggest taking your batteries to a marine battery shop and have them give the batteries a full checkup.

dtwofoot · Feb 15, 2015

Is there a drain on the battery? Disconnect your Positive terminal, place your multi-meter in ohms and one lead on the disconnected terminal and the other on ground, should read open circuit (infinity). Make sure all battery is disconnected from the positive side or your ohm meter will blow a fuse! 0 ohms is a short to ground and any low resistance reading is conductivity to ground.

Bill Roosa · Feb 15, 2015

When doing dtwofoot's diagnostic be sure you disconnect any "always on" devices that use power to maintain memory (the stereo is usually the item). Alternately you can just disconnect the positive terminal(s) and set the multimeter to amps and read between the battery positive and the positive cable that attaches to it to get the actual amps flowing. Given that the batts went from 13.xx to 10.5 in short order, I'd try charging for more than an hour. 10.5 is about 100% discharged and an hour on the charger is not enough to put much back in. The every first thing I'd check is for corrosion on the 3-way switch and the battery terminals themselves. 99.44% of all electrical problems on boats are corrosion related

Maine Sail · Feb 15, 2015

You possibly have a battery with an internally shorted cell... Isolate this battery for any further testing just for safety purposes..

Terry Cox · Feb 19, 2015

P42 Batteries

When we purchased our 1991 P42 in 2002 it had two wet cell 8Ds that had been on the boat for several years. Three years later I replace them with Interstate wet cell 8Ds that lasted for almost ten years. Then about three years ago when that set reached their end of life I replaced them with AGM 8Ds.

I had good results with the Interstate wet cell 8Ds and always took good care of them. Ditto with the new AGMs, but heavy suckers. They seem to accept a charge faster than the wets and of course no need to add water.

If it were my boat I would stick with the 8Ds.

As a suggestion, most marinas can do a battery load test for you without removing the batteries from the boat. Ours did it for free. If they determine that you have a dead cell or short, perhaps you can go back to where you purchased them for an adjustment.

artboas · Feb 23, 2015

YES!!!!!!!!

hunter43sail said:
It looks like the batteries are bad. I am going to swap them out for 4 6 volt batteries.

Golf cart batteries are the best solution ever
They are :
Cheap
Reliable
Easy to lift (huge advsntage)

You will never regret this

Get water miser battery caps. Just do it. You will be astonished with how good they are. Save 80% of water .

Steverhnm · Feb 23, 2015

What brand or model of Water Miser caps are you using?

artboas · Feb 23, 2015

They are from Flow systems
I bought standard height
They are FABULOUS .
You can fill batteries without removing caps.
Plus, they recycle the gas into water.
You will love them

seadaddler · Feb 28, 2015

Great

I did the same thing in 2011 and replaced those pain interstate 8D's
and had one changed in early 08 under warranty and to be honest
they really were never worked that hard and was mostly hooked up to shore power most of the time.
I replaced them back in 2011 and they are 4-6volt T-105 trojan's and they get a very hard work out as everything on my boat works off 12volt most times from my inverter and they get charged mostly by solar and have ref on 24/7 on 12volts.
The Trojan's are worth the $$$$$$.
Nick