Balancing House Batteries-Help

Paul F · Jun 1, 2010

A friend put a transformer or something like it in his boat to allow 110v ac to run his 12v appliances while at the dock. His system by-passes the battery bank and does not draw on their change at all. I will see him this week and ask the name of the device etc. He has used it for about a year and likes it very much.

FastOlson · Jun 1, 2010

rfrye1 said:
We have two (wet cell) 4D house batteries plus a dedicated start battery. For our charging system we have a 10 year old Freedom/Heart Inverter (2000w). We seem to only abt 2 years out of these batteries. During the winter we sometimes leave the boat unattended for 5-8 weeks with the battery charger ON, also the 12v fridge on too (cold beer).

Would I be better off to turn it all OFF during those long unattended periods? Is my battery charger just cooking my batteries?
What do you "experts" think?
Thanks. Bob

Hi Bob,
Until an expert checks in.... My uneducated guess is that something is amiss in your charging system. If you leave a modern multi-stage charger on "float" mode all the time at the dock those batteries should last five years with ease.
We get 5 to 7 years out of our house bank. That's two large golf cart type Trojan 6 volts. Our DC fridge is running from early spring until we put the boat to bed in November.
I do check the liquid level in the batteries once a quarter and do add a little distilled water once in a while.
While it *sounds* like the batteries are getting too much charge voltage and are being "cooked" i.e. having the liquid boiled off and drying the plates, this is too much to assume when trouble shooting over the internet.
Have you been checking the float voltage and monitoring the liquid level each month?
Let us know some more details, if possible.
Good Luck,
L

Don12364 · Jun 2, 2010

I think its the Beer!

The Freedom charger keeps charging in 'acceptance mode' until it reaches its 'set point', or for a time set in the remote panel (or Link monitor). This is where the battery has reduced its demand on the charger to a small proportion of its capacity. If you have the Link 1000 battery monitor as I have this is 2% (or 8 amps with a pair of 4Ds). A second criterion for the set point is that the battery voltage has risen to 14.4V. At 14.4 volts the cells are gassing which is bad news for gel cells and for open wet cells will mean frequent topping up.

At the set point the charger switches to 'float charge', when normal charging is terminated and the voltage held steady at 13.5V. This is the condition you should be aiming for.

My guess is that your refrigerator, being on all the time, prevents the battery reaching its set point or, if it does, it quickly drops the battery to below the point where the charger detects the need to begin charging again - so the charger continuously cycles between acceptance (gassing) and float. I have watched mine do this despite what it says in the manual.

Do you have the Link battery monitor which should enable you to watch the process? If you do not then check the DIP switches on your remote control. The manual will be found on http://www.xantrex.com/web/id/591/docserve.aspx.
The remedy is to not run the fridge when you are away from the boat. This is wasteful anyway and just means no cold beers until an hour after you come aboard. But then you will need to make sure you do get recharged after each weekend.

FWIW my H376 lives on a mid-stream mooring on a river and has no access to shore power.
My house bank is 400Ah like yours and I have only replaced my batteries once in the 14 years since the boat was new in 1996 so I am getting 8 years or more from a set of ordinary no maintenance non gel, non AGM batteries.
Rather than over charging, my problem is to get the charge back into the batteries after a weekend away on the hook.
The refrigerator is a terrible thief of power, so I plug in whenever I get the chance.

seadaddler · Jun 2, 2010

Always

I have same set up except the ref I changed one year after new.
I have 2 4 D's and the 2000 inverter charger and is pluged in all the time here in Florida with the ref on all the time and Hum set up on my AC to keep moisture down inside my boat.
The ref was 12 volt only when new and would always need to be charging the batteries so I called the manufactor and got a converter from them so it runs on 110 at the dock and auto switches to 12 volt away.
I do check the fluid regularl.
Nick

walt · Jun 2, 2010

This may or may not be related to the OP issue..

For several years, I had two "identical" 12 volt (wet) batteries which were always wired in parallel. These batteries were always on solar with a simple charge controller and sometimes on a battery maintainer.

I was not good about checking water levels but when I did, I would usually find one battery had almost no water used but the other battery was almost empty. The batteries set had one good season, one OK season, limped through a third but were both trashed - one really trashed.

Ive now gone to two six volt batteries in series with the same charging system and just checked the water after 7 months. Both batteries needed about the same fairly small amount of water. Cant say if these will last longer since Im only on the first season but at least I don't seem to have the imbalance issue.

I think if you parallel wet cell batteries, you need to be good about keeping the water checked.. More so than just a single battery.

Stu Jackson · Jun 2, 2010

Gotcha again

To parallel Donalex's post, you should read this and make it work for you. Any question, please ask:

http://c34.org/bbs/index.php/topic,4922.0.html

If you have a Link controlling the Freedom, you can manipulate the parameters to have the algorithm to have your charger running on float all the time. Of course, you'd have to reset it when you're normally using the boat.

It could well be that you are cooking your batteries by having the fridge run all the time kicking the charger into absorption most all of the time. 14.X+ volts all the time is NOT healthy for batteries, regardless of the amperage. Other than a friend who had his office a stone's throw away from his boat, I have no clue whatsoever why anyone would leave a boat plugged in with the fridge on and the 1-2-B switch ON when they are away from their boat. Cold beer? That's why they invented 7-11. Hey? Dontcha have to replenish the beer sometime? Bring some cold ones with you. Plus, if something goes wrong, you'll end up with a smelly fridge. Hope ya didn't leave any mayo in there...

druid · Jun 2, 2010

Hmmm...

I had the almost identical system in my Catalina 36: a 4D house battery and a Group 27 starting, and a NovaKool fridge. To begin with, I had both batteries connected together and charged with an El Cheapo Canadian-Tire charger. I was going through batteries every 2 years or less.

Then I changed to a Xantrex Truecharge 40, with separate charging ccts for each battery. Even with the fridge, I was getting 5+ years out of the batteries.

I suspect your charger.
druid

Snotter · Jun 3, 2010

If your fridge is kicking your charger into boost then something is wrong. You may need to get a bigger charger.

Bill Roosa · Jun 3, 2010

temp switch

Don't forget to change the temp switch to cold. If you leave it on warm or hot the batteries will suffer greatly. assuming that you leave it in a cold environment of course.
I leave my batts on charge all the time. never disconnect them. But you have to show up at least every 21 days as my charger does an automatic equlization charge which tends to boil off a little water.
7 years on trogan 110s and no problems yet.