Disconnect Batteries for Desulfation

[GeeSag]

Is it required / recommended to disconnect the batteries from the trailer when using a Battery Minder due to the Voltages / High Frequency associated with the Desulfation process?

[dznf0g]

No, been using a batteryminder hard wired desulfater installed in the AS for 5 or 6 years. No adverse effects.

[azflycaster]

Many of the multi stage converters have a Desulfation stage which happens during normal operation. No need to disconnect.

[Rich Jenkins]

Did a search to find this thread.

I have a new to me 2018 23 FC FBQ. I'm not seeing quite what I'd like on the (I assume original) two AGM Lifeline batteries. On a sunny Florida day, out in the storage lot, just after noon, with the coach sitting for a week, the batteries were at 75% state of charge, according to the on-board display of the solar controller. Charging amperage from the solar panel ranged from 2 to 4A. I was a bit surprised they weren't near 100%, but then I thought, hey, these are going on three years now. I'm going to keep them under observation as we start to go camping, but I may be looking at replacing them.

Before I do that, though, I had heard about battery maintainers that had built in desulfation. Reading more, I wonder if the batteries I have might have become sulfated?

Is this reversible? I looked online briefly and came up with a Batteryminder charger/minder that has a desulfation mode as part of it's normal operation:

https://www.batteryminders.com/2012-...-worldwide-use

Can I just connect this unit across the 12V (parallel) of the two batteries in the battery tray? Or do I need to remove the batteries and bring them home to put them on charge to desulfate them one at a time?

I figure this might be worth a try ($100 or so) as opposed to new Lifeline 80 Ah AGMs ($445 apiece), or before I go for more Ah with 100/200/400 Ah Lithium / new charge controller / shunt etc. etc. etc. We are not huge boondockers, so if I can get a few years more use out of these Lifelines for $100, I'd vastly prefer that.

[richard5933]

Seems like an awfully high price for 80Ah AGM batteries.

What size are you looking at?

[Rich Jenkins]

Originally Posted by richard5933

Seems like an awfully high price for 80Ah AGM batteries.

What size are you looking at?

I will admit I didn't spend too much time looking for prices; I just wanted to get a ballpark figure on like for like (i.e. 80 Ah) replacement. Amazon for instance, is at $449:

https://www.amazon.com/Lifeline-Mari.../dp/B0029XPWFE

I appreciate the benefits of Lithium in terms of usable Ah, for sure, but I don't want to start down the slippery slope of buying new batteries, a new charge controller etc. etc. unless I have to (and if these Lifeline's are toast, I will).

Having just bought the unit, I'm not thrilled with dumping in another $k+ for batteries, if the existing batteries are simply sulfated, and I can hold off or even reverse the process for the cost ($100) of a Batteryminder. They are only three years old.

[richard5933]

Yeah - I'm seeing AGM batteries for about 1/2 what you found on Amazon. Likely you can find them locally for the mid-$200 range.

Those batteries might be a year older than you think - no telling how long they sat on a shelf before being installed in the trailer. Depending on how much you'll be relying on them, it might be worth it to just replace them right now and be done with the worry.

[Rich Jenkins]

Originally Posted by richard5933

Yeah - I'm seeing AGM batteries for about 1/2 what you found on Amazon. Likely you can find them locally for the mid-$200 range.

Those batteries might be a year older than you think - no telling how long they sat on a shelf before being installed in the trailer. Depending on how much you'll be relying on them, it might be worth it to just replace them right now and be done with the worry.

For sure; I DIY replaced the original 80 Ah AGM in my run-about car this summer with a 92 Ah Duracell SLI49 Group 49 from my local Batteries Plus. Ran me about $199, all in, with the rebate etc.

I'll look into cheaper options. Appreciate the tips.