Type of battery charger to buy

[chrisski]

If these are AGM batteries, I urge caution, as you should not be hearing them gas.

Well, maybe you will hear the gas bubbles as they charge, but the re-combiners should catalyze it back to distilled water, and drip back into the cells, Any venting gas is wrong.

I have flooded lead acid. My understanding is these can vent in the last stages of charging.

thought about gettingAGM, but decided on FLA batteries instead. The manufacturer’s tech recommended I charge these FLA batteries in AGM mode when I use my high amperage charger.

Also, much more bubbling then venting.

I feel I’m in uncharted water so I appreciate the comments.

[Mike90250]

Good. I'm glad they are flooded, perfectly normal for them to gas a lot. Then you get to add distilled water to make up for what was dissociated by electricity. In the afternoon, my battery shed sounds like a room full of snakes , from all the gassing. 13 gallons of distilled the last time I topped them up.

[chrisski]

Good. I'm glad they are flooded, perfectly normal for them to gas a lot. Then you get to add distilled water to make up for what was dissociated by electricity. In the afternoon, my battery shed sounds like a room full of snakes , from all the gassing. 13 gallons of distilled the last time I topped them up.

I had them on a 4 amp charger for a week, so it was not the 26 amp deep charger I got. I opened up the caps and I may need to add 1/8th of an inch to the cells, so for 12 cells between the four batteries, maybe a cup or two total for me. I think the bigger charger would have been quite more.

Once I put these in the RV and am charging the bank with 35 or 40 amps, I wonder if I will be able to hear them.

[chrisski]

Hooked the "Large" 26 Amp Charger to two 6 Volt Batteries in Series, and it stated nearly charged. The Smaller 4 Amp Charger had rated the 6 Volt Batteries at 50% - 75%. I guess the best way to tell is a temperature adjusted hydrometer.

I also needed to add a total of two or three cups of water to four batteries after the first charging.

[Mike90250]

The hydrometer will give a definitive state of charge, and also if there is much difference, you may need to EQ the bank

[chrisski]

The hydrometer will give a definitive state of charge, and also if there is much difference, you may need to EQ the bank

I guess where I’m stuck with equalization, is how to actually do it. Both chargers I have for the batteries have an automated mode where it will choose to equalize the batteries.

The only way I’d have to manually equalize the batteries is not charging in the garage, but after the RV is set up for solar to program the charge controller to enter the equalization mode.

The other option would be on the charger to press the 30 amp 30 minute battery boost mode and hope that is close enough to equalization, but I’m not sure I want to rely on hope as a plan and not tech data.

[Mike90250]

Worry about it after you measure the cells. Maybe you can get them charged fully one day, and perform another full charge the next day, and then measure.

[chrisski]

Just finished my first test of my batteries and with them supposed to be charge to a specific gravity of 1.277 to be 100%, mine were charged to a temperature corrected 1.285, with very little difference between the cells. So I got .008 overcharged or about 105% charged. Now, I had two chargers on these batteries, one which had the electrical readout between 50 and 75 for all four batteries, and the other had the readout between 75 and 100 for all four batteries.

Since I think there is some "art" involved in this, to ensure my batteries don't overcharge:

1) I am going to remove them from the 600 watts of Panels when I store the RV. I thought about either putting one bank of 300 watts of panels on it, or even installing a second 100 watt panel just to charge the batteries but I opted against it.

2) I have a set of shelves with a charging and measuring station I built to keep my 270 LBS of Batteries charged. Now that they are charged, I am not going to leave the float charger connected. I will take specific gravity measurements every week to determine their health, and put them on the charger.

3) If there comes a point where I get sick of lugging 270 LBS of batteries between the RV and my house, I will start with rigging a 100 Watt panel to my MPPT charge controller, and take hydrometer readings and check water levels every month. I see myself going to this option sooner than I hope. Those batteries are heavy, and I'm really not sure if they're mode to be moved around a dozen times a year.

The other thing is maybe you are reading 105% full because the temp compensation was off, or at some point in time, electrolyte was added to refill, instead of distilled.

Could have been. I have a hydrometer I got at the Auto store that mentioned nothing about temperature compensation, so what I did was add .008 to the readings since the temperature was 100° F. The Hydrometer was reading 1.277 +/- .002 for each of the 12 cells I measured.

I have a Deka Hydrometer coming, unfortunately, the first one was delivered broken so I could not do that.

2 of the batteries had been sitting for days and the other for 2 hours, and I wrote the measurement on the third time I pulled fluid. It showed more charged between the first measurement and the last in some cells, so I think taking multiple measurements did circulate the electrolyte and water.

[AndrewCoates]

NOCO Genius looks well built. Hooked it up to a battery and it charged it up and then shut down. I put a bit of a load on the battery and charger started up again, just as I would have expected. I think it will be perfect for my Boler trailer.

[chrisski]

NOCO Genius looks well built. Hooked it up to a battery and it charged it up and then shut down. I put a bit of a load on the battery and charger started up again, just as I would have expected. I think it will be perfect for my Boler trailer.

I like the charger. It's also the only charger I found that charged at 13% of the C20 rate like my tech sheet says to charge my batteries. I wish it had a 6V mode in addition to the 12V and 24V. I couldn't find any charger to charge 26 amps and 6 volts. Perhaps someday the batteries will be unbalanced and would be best to put a single battery on a charger, but for now, its fine.