RV Voltages too high while charging

These so called "battery experts" are crazier than a s---house rat. From one extreme to the other they veer and wander. Lost little children trying to find their way. Man this is even worse when I had the company. I guess no one wants to represent electro-chemical reality anymore. "Oh! Charge at no higher than 14.4 volts! No wait a minute! 15.3! No! Nothing is correct! Where did I put the cyanide supplement pills?"

Ever heard the term "Fart In A Whirlwind"

It's when you allow ignorant people to do your thinking for you.

There is enough VALID informatiin on this site to educate a novice more thoroughly than what 80% battery peddlers will EVER know. If you choose to ignore valid information please weep in silence. The whirring funnel cloud noise of utter confusion is distracting.

Hey my car is not starting up fast every morning. Quick! Call the salesman - he'll know what to fix. Only MANUFACTURERS can properly represent proper battery care. Not Interstate, sears, Kragens, Wal-Mart or Dairy Queen. Interstate is a battery merchandiser. They are experts in warehousing, distribution and stocking batteries from whatever manufacturer they can strike a deal with. Imdividual distributors are FRANCHISES just like McDonalds and the corner Chevron station. I've met a few distributors who knew their product enough to offer decent service. Then I've met others who were dumber than a freshly dried mud pie. They managed their business well and rotated stock and kept good books but their knowledge of batteries was pathetic. Same issue for Sears Roebuck. A guy comes swaggering out with an impedence meter and proceeds to heap enough B.S. onto a question to properly fertilize the eastern half of the county park.

Some of you need to get whacked over the head with a baseball bat to get your attention?

If you do not trust the -correct- information on this forum TELEPHONE THE BATTERY MANUFACTURER. They have people called application engineers whom are a lot more savvy than a battery peddler.

Yes 15.3 volts absorbsion is too high except for Fargo North Dakota in January. 14.8 volts to 15.3 volts is half a volt too high. Even .2 volts greater than Top Charging limit.

Sometimes I think my time spent here is reaching too few people. Grumble Snivel

jrnymn7 wrote:
I've pretty much given up on trying to find specs on my batteries, but I just remembered coming across a dealer website a while back, that said max 15.3v. So it is very likely those kinda numbers are max "over-charging" voltages.

Take the time to "carefully" read this. Different charging profiles CC CV CC charging profile.

Chandalen wrote:
Thanks for all the input!

I called Interstate. The tech said he can not recommend absorption voltage below 15.25 He mentioned getting a Dc-Dc adapter for the inverter as mentioned before. He said if I ran below 15.25 for absorption then I should go as high as I can, and to equalize the batteries every 21 days, if under heavy use.

I think I'll put the voltage for 14.9 and see if tat works well, if not, I'll drop it to 14.8 Of course I'll hydro test the batteries regularly and if really needed, I can reprogram the controller for the higher voltages when we are not using the camper.

My take is that if a distributor isn't telling folks to under charge their batteries, he's trying to get them to boil the suckers dry. :(

I would set the charge at 14.8 V, use them for a few days, and then dip the hydrometer to have a baseline SG. Keep them at 14.8V and dip every so often to see if your batteries are keeping that SG. If it starts sliding down, even a small amount, time for a voltage increase to give them a stir. There's no need to keep up that higher voltage, putting your appliances at risk.

I've pretty much given up on trying to find specs on my batteries, but I just remembered coming across a dealer website a while back, that said max 15.3v. So it is very likely those kinda numbers are max "over-charging" voltages.

MEXICOWANDERER wrote:
So I flip the rear view mirror up if I see red lights behind me from the Syntax Police.

Just flip em off

http://gawker.com/humiliated-boston-grammar-bully-teaches-us-all-shut-u-1656913317

It is a fake "issue." The "normal" definition of "absorption voltage" is the Vabs that you get the batts to before holding it there while amps then taper during the absorption stage.

Somehow, as was mentioned above, the Interstate specs have mixed up "Absorption" with "Finish" , which itself is a sort of term for "Top Charging" as Mex uses that term, and "Overcharging" which others use for the same sort of thing.

Ignore all that, and just set your Vabs to 14.8v. Every so often do an overcharge. Check your SG after the overcharge. If not to "Baseline SG after that, then do another overcharge. Once you get to Baseline SG you can go back to regular routine for another month or so.

It is true that if you can do say 75-95s on solar every day, you will not need overcharges so often to hit baseline SG as when doing 50-90s. If you can only do 50-90s successively, you will have a hard time with "progressive sulfation" reducing your battery capacity, and you will need an overcharge more often than once a month to keep up.

The really hard part is howinheck can you do an overcharge when on solar. You need the batteries to be "full" before you can do an overcharge, and the best you can do every day is to get them almost full. Bummer!

Split the bank. If you have two 12s or four 6s, then take half of the bank off the rig draw and just charge that half up to full and then do its overcharge and "get them clean." Then put them on-line and next sunny day do the other half while running the rig on the other half that has already been done.

If your controller does not have an equalize setting, then just by- pass it and go "panel direct" to do the overcharge.

MEXICOWANDERER wrote:
Shoot, I'm DEAD BROKE most of the time. One foot in the poorhouse and the other on a banana peel. So I flip the rear view mirror up if I see red lights behind me from the Syntax Police.

The checks keep coming as long as you are alive, so you are not dead broke, until you are dead, and then the checks stop coming.

MEXICOWANDERER wrote:
Shoot, I'm DEAD BROKE most of the time. One foot in the poorhouse and the other on a banana peel. So I flip
the rear view mirror up if I see red lights behind me from the Syntax Police.

Disconnect solar fire up inverter fire up fridge on 120 reconnect solar.

Thanks for all the input!

I called Interstate. The tech said he can not recommend absorption voltage below 15.25 He mentioned getting a Dc-Dc adapter for the inverter as mentioned before. He said if I ran below 15.25 for absorption then I should go as high as I can, and to equalize the batteries every 21 days, if under heavy use.

I think I'll put the voltage for 14.9 and see if tat works well, if not, I'll drop it to 14.8 Of course I'll hydro test the batteries regularly and if really needed, I can reprogram the controller for the higher voltages when we are not using the camper.

BFL13,
I've never actually been in a situation where I "needed" to do it. I do it when I'm trying to get my controller to deliver full panel charging amps when the batteries don't need it, mostly to satisfy my curiosity and confirm that my stuff still works properly. So I apply a big DC load via running the fridge on AC through the inverter. Then the controller opens the flood gates and I can verify that the panels can deliver full rated output.

But to get around the situation you've described, I'd first disconnect the panels from the controller via a circuit breaker. Battery voltage will then drop and I can turn the finicky inverter on. Apply a load on the battery via an AC load on the inverter and then I can connect the panels to the controller again since battery voltage is being held low by the load.