Charging deep cycle batteries

[Herd_Fan]

I have a couple different brands of batteries...Everstart Marine&RV and Interstate Marine/RV. Most chargers on the market allow you to select "standard, agm, or gel". Which setting is recommended?

[theoldwizard1]

pianotuna wrote:
They are not a true deep cycle format, so try not to discharge them more than about 20%.

Concur !

Marine batteries are a compromise. The only readily available TRUE deep discharge batteries are 6V golf cart batteries, available at Sams or Costco.

[red31]

last I knew both everstart and interstate marine/rv batts where made by the same company, Johnson Controls Inc.

I'd recommend standard from the three suggested.

Also reccomend you disconnect them in storage and charge monthly or every other month. Better yet get 100watts of solar to keep em in good shape in storage disconnected from trailer loads.

[wa8yxm]

MARING/deep cycle are Standard.

[pianotuna]

They are flooded jars. Use the standard setting--but do track the voltage. It needs to get to 14.8 if the charger can do so.

I managed to get 9 years out of a set of "marine" jars. They are not a true deep cycle format, so try not to discharge them more than about 20%.

The ideal charger would keep the batteries just below the gassing voltage, and then at about 95% state of charge move up to one bubble per second.

[wolfe10]

Yup, brands mean nothing.

Technology is what is important. They are wet cell, gel or AGM. Very likely wet cell.

[BFL13]

Different brands but likely the same maker. Use "standard" or "flooded" or "wet" depending on the name used.

For those marine/rv batteries, the best result is from a "low and slow" recharge to full, using about a 10% charging rate and let the voltage rise slowly to 16v.

If you use a high recharge rate in amps, it just overwhelms the chemical process and it never gets done fully.

Unfortunately, most chargers only go to 14.x and then shut off automatically, so you "can't get there from here"

There are some chargers or converters that will let you do lower amps to a higher voltage, but you have to know their specs.

[SoundGuy]

Herd Fan wrote:
I have a couple different brands of batteries...Everstart Marine&RV and Interstate Marine/RV. Most chargers on the market allow you to select "standard, agm, or gel". Which setting is recommended?

Well you haven't said what type of batteries these are but from your description it seems they're probably just good ol' flooded, in which case you'd use what you've called the "standard" setting.