Which Battery?

[Patch]

I have a new to me 2018 21c. The deep cell 6volt batteries will soon need to be replaced. It was suggested that I get AGM batteries because they are easier and safer, especially since they are stored in the bench seat. I'd appreciate knowledgeable feedback. TIA.

[John in Santa Cruz]

Most true deep cycle golf cart batteries are flooded, not AGM, AGM deep cycle batts are a lot more expensive. your batteries are in a ventilated battery box, so that should alleviate any concerns about outgassing.

[Ron in BC]

I agree, it's a non-issue.

Ron

[alanmalk]

Originally Posted by John in Santa Cruz

...
AGM deep cycle batts are a lot more expensive. your batteries are in a ventilated battery box, so that should alleviate any concerns about outgassing.

High quality AGMs are indeed more expensive* than flooded. But in the 7 years I used them (having obtained them at a great sale price), I never had to add water. (Humor here, ). I also never had my propane detector wake us up with a false alarm due to outgassing - mentioned a fair number of times on this forum. And looking closely at the specs, my AGMs could be discharged a bit deeper than flooded for the same total cycle lifespan (a minor point in my opinion but some folks do worry about going past the 50% depth of discharge). Small advantages but they do add up and tipped the equation to AGMs for me.

* - Currently brand "X" lithiums are cheaper than high end AGMs.

[Rockhead]

I know it’s been discussed a few time but what if any changes to equipment do you have to adjust or change out in going to AGMs it getting time to replace our original batteries

[Perry Butler]

Originally Posted by Rockhead

I know it’s been discussed a few time but what if any changes to equipment do you have to adjust or change out in going to AGMs it getting time to replace our original batteries

Nothing needs to be changed because they charge like flooded. If you can, turn off your equalizing, depending on your choice of batteries. Our friends decided that going on 8 years to replace their Lifeline AGM (top of the line) batteries with identical batteries, and Lifeline told them it was OK to equalize occasionally, and they left their equalization cycle running. Don't know if you can get away with equalizing with cheaper AGM's though.

Food for thought,

Perry

[rubicon327]

Originally Posted by alanmalk

High quality AGMs are indeed more expensive* than flooded. But in the 7 years I used them (having obtained them at a great sale price), I never had to add water. (Humor here, ). I also never had my propane detector wake us up with a false alarm due to outgassing - mentioned a fair number of times on this forum. And looking closely at the specs, my AGMs could be discharged a bit deeper than flooded for the same total cycle lifespan (a minor point in my opinion but some folks do worry about going past the 50% depth of discharge). Small advantages but they do add up and tipped the equation to AGMs for me.

* - Currently brand "X" lithiums are cheaper than high end AGMs.

There are still false alarms on the propane detectors with the "vented" battery boxes. They are never sealed perfectly. We never had any problems until I moved our dual 6V flooded Interstates inside under dinette bench to make room for mini-split condenser on the tongue. They were in a high quality battery box with vent but we still had false alarms on the detector. Also a pain in the rear to add water. Was going to move to AGM's but decided on a larger retrofit that included lithium. I would seriously consider the switch to AGM's.

[SageRpod]

Originally Posted by Patch

I have a new to me 2018 21c. The deep cell 6volt batteries will soon need to be replaced. It was suggested that I get AGM batteries because they are easier and safer, especially since they are stored in the bench seat. I'd appreciate knowledgeable feedback. TIA.

If your battery box seals properly and is vented, save the money and go with the flooded instead of the AGM. You should have easy access to the batteries to add water for maintenance.

[Telescopist]

Originally Posted by Patch

I have a new to me 2018 21c. The deep cell 6volt batteries will soon need to be replaced. It was suggested that I get AGM batteries because they are easier and safer, especially since they are stored in the bench seat. I'd appreciate knowledgeable feedback. TIA.

How do you know that they will need to be replaced soon?

[Telescopist]

Originally Posted by rubicon327

There are still false alarms on the propane detectors with the "vented" battery boxes. They are never sealed perfectly. We never had any problems until I moved our dual 6V flooded Interstates inside under dinette bench to make room for mini-split condenser on the tongue. They were in a high quality battery box with vent but we still had false alarms on the detector. Also a pain in the rear to add water. Was going to move to AGM's but decided on a larger retrofit that included lithium. I would seriously consider the switch to AGM's.

The propane detectors also have a shelf life. I replaced mine last spring. That ended my problem with false alarms.

[BobG]

I ruined 5 Lifeline AGMs by accidentally overcharging them. It was expensive to replace them even with $100 discount per battery. If I had easy access to maintain flooded batteries, I would consider going that route if I wanted to save money. If cost wasn't an important consideration then I would go AGM because they are a no hassle battery. Flooded batteries take regular maintenance. Forget to water them on schedule, maybe they get more expensive than AGM alternative.

If the choice was not limited to AGM or flooded, I really like Lithium the best. To me, they are a no hassle battery. I don't ever worry about how far they discharge. If I accidentally leave the A/C on all night, they will discharge to near the lower limit. If they go down to the limit, then they would be turned off by the BMS and not be damaged.