Will Equalizing batteries hurt my fridge?

[SV Demeter]

We are at at a marina for a few days and while on shore power I thought I would take the time to equalize the batteries. I know Im supposed to not run sensitive electrical equipment while equalizing but we live aboard and have two fridges with food in them. One is a stand alone dometic plug in model that I can run on 110 instead of 12v so its really just the built in reefer that has a frigoboat unit in it. My question is will the higer voltage harm it?

Thanks,

[DotDun]

I open the main switch to all house loads while equalizing. But then I only run equalization for ~1 hour (16v), stuff doesn't get that warm in the frig.

[SV Demeter]

Just 1hr? I was thinking equalization charge should be for like 8hrs? I have a 1040ah bank of trojan T145s. They are only about 4 months old and not giving me any trouble I just thought an eq charge would be good PM.

[sailorboy1]

I think not turning off ou 12V loads is like playing Russian Roulette. I would turn off every 12V item.

If your freezer and frig is full of cold stuff already the food will be fine for some time with the system not running as long as you stay out of it. Otherwise a bag of ice seems like cheap protection/insurance in this case.

[DotDun]

I have 450ah of T105s. My (limited) knowledge/opinion of equalizing is to do it only when it needs it as you are destroying plate material along with removing sulfation.

I run an hour at 16v a couple times a year.

[svHyLyte]

Originally Posted by SV Demeter

We are at at a marina for a few days and while on shore power I thought I would take the time to equalize the batteries. I know Im supposed to not run sensitive electrical equipment while equalizing but we live aboard and have two fridges with food in them. One is a stand alone dometic plug in model that I can run on 110 instead of 12v so its really just the built in reefer that has a frigoboat unit in it. My question is will the higer voltage harm it?

Thanks,

The FrigoBoat will not withstand the voltage spike. Pick up some bags of ice, or better, a block of "dry ice" that can be had at some grocery stores and keep the fridge chilled with that while the equalizing charge is being applied. Note that an hour is not likely to accomplish much. Equalizing normally takes several hours when needed. I only do an equalization when I see pretty notable diferences in SG in the cells after fully charging our batteries but if so, I will equalize for 6-8 hours per the instructions on the Trojan web site. You might look at the Company's technical notes, regardless of the make of your batteries, for more information. Click on: Trojan Battery Company

[SV Demeter]

Guess the smart thing would be to first check sg of my cells and see if there is any need to eq in the first place. Thanks folks.

[Maine Sail]

Originally Posted by SV Demeter

Guess the smart thing would be to first check sg of my cells and see if there is any need to eq in the first place. Thanks folks.

Bingo... An even easier method is to know your "normal" morning voltages or normal loaded voltages under your average loads. If this voltage begins dropping from where you are used to seeing it, then that may signal its a good time to check the SG.

I see lots of batteries destroyed by people over checking SG and contaminating the cells. Every time you open the cells you run a risk of contaminating them by crud and crap falling in there. Even a little foreign mineral content can begin to drop the gassing voltage of the battery.

Many owners also don't properly store their hydrometers and they can become contaminated too. A dedicated Tupperware cleaned with distilled water is the best place to keep your hydrometer, and only your hydrometer.

Personally I switched from a high quality Freas hydrometer to a sight refractometer. The refractometer uses a single droplet of electrolyte vs. filling & draining multiple ounces of electrolyte in each cell every time you check it. I find the little glass eye dropper is easier to keep from getting contaminated than a large hydrometer. I also find the refractometer easier to read but that's probably just my personal observation.

One option when equalizing is to split off part of the bank and equalize only the disconnected batteries. I generally prefer to do them in pairs if 6V but on a large bank this takes time.. Once half the bank is done you then switch the wires and do the other ones that were powering the loads.

If you've been charging with absorption voltages at 14.6V - 14.8V it is unlikely you need an aggressive EQ cycle at 4 months. If you've been charging at lower voltages and not getting to full very often you may need a short EQ cycle..

[SV Demeter]

Originally Posted by Maine Sail

Bingo... An even easier method is to know your "normal" morning voltages or normal loaded voltages under your average loads. If this voltage begins dropping from where you are used to seeing it, then that may signal its a good time to check the SG.

Thanks withour soalr panels we rarely see voltage below 12.4 and normally at the end of the day are about 12.8.


Personally I switched from a high quality Freas hydrometer to a sight refractometer. The refractometer uses a single droplet of electrolyte vs. filling & draining multiple ounces of electrolyte in each cell every time you check it. I find the little glass eye dropper is easier to keep from getting contaminated than a large hydrometer. I also find the refractometer easier to read but that's probably just my personal observation.

I have not yet useed my hydrometer but did clean it well with distilled water and keep it in a ziplock. I check water levels every 30 days and so far have not had to add any. I use water miser caps http://www.solar-electric.com/batwatmiscap.html

One option when equalizing is to split off part of the bank and equalize only the disconnected batteries. I generally prefer to do them in pairs if 6V but on a large bank this takes time.. Once half the bank is done you then switch the wires and do the other ones that were powering the loads.

Had not considered this method will need to look at where inverter/charger connects and see how hard this would be.


If you've been charging with absorption voltages at 14.6V - 14.8V it is unlikely you need an aggressive EQ cycle at 4 months. If you've been charging at lower voltages and not getting to full very often you may need a short EQ cycle..

My absorbtion voltages are not that high. My Outback Flexmax 60 solar controller never gets out of of bulk mode. I need to check the settings on it but I believe we are getting the batteries well charged regularly as when I do start the engine and the batteries are already fully charged I typically only see about 25-30amps of alternator output which for a 1040ah bank is only 2.4%- 2.8% charge acceptance. My alternator is a 100amp with temp sensors for alt temp and battery temp.

When we charge from the engine Im using a Balmar MC-614 regualtor with the preprogrammed FDC algorithm. Its bulk is 14.6, absorb 14.4, and float 13.4 but I feel like its absorb volatge is actually something lower based on readings from the Victron BVM, I feel like Absorb is something like 13.95 andI think thats what Im seeing on the regulator screen when it says Cv- calculated voltage. I need to have another look at the regulator when the engine is running. Im considering going into the MC-614 and manually configuring the Bulk, Absorb, and Float voltages but I hate those reed switch exercises. When I look at the Trojan info I got with my T-145s it calls for Absorb at 2.35v-2.45v per cell which translates to 14.1-14.7 I believe for 6 cell or 12 volt setup. It Also calls for Float at 2.20 per cell or 13.20, and 2.58 or 15.48 for equalization. There is no bulk charge volatage given that I have seen.

So I dont think I have any problems and I believe Im taking good care of my batteries but I do still need to do a sg test.