Pb-C AGM Batt questions

Steve777

New Member
Joined
Oct 23, 2020
Messages
27
So I am curious to get some ideas/direction on the care and feeding (aka charging and use) of lead-carbon batteries.

They seem to be a fairly new design, with what would appear to be some real advantages for stationary uses (high current charging and draw, high cycle counts, much cheaper than Li alternatives). However I have not found much in the way of detailed info on their charging and care details. I don't know if that is because they are similar in those regards to standard Pb AGM batts, or if they just have not been around and used enough for folks to become familiar with them.

In particular, I am wondering how I should vary their charging from what I would use on a standard AGM batt pack. And also to what degree one can draw down their SOC and how that effects cycle life. If anyone has any thoughts on these (or anything else regarding Pb-C batts) I'd like to hear.

TIA
 

snoobler

Solar Honey Badger
Joined
Jul 10, 2020
Messages
8,430
Location
HBR, AZ
There is no care and feeding of AGM batteries. You simply operate them within the published limits.

I have not seen offerings of lead-carbon AGM batteries. What I have seen is flooded, and their costs are typical of LFP and similar life @ 80% DoD.

Here's an example:


AGM batteries typically have cycle lives half that of properly maintained flooded. If you're looking for cycle life, AGM is typically not the best choice.
 

Steve777

New Member
Joined
Oct 23, 2020
Messages
27
Care and feeding probably wasn't the best phrase for what I meant. Yes AGMs don't require watering or measuring SG, but they (at least some) do require occasional equalization although not as vigorous a charge as flooded do. (My previous Pb AGMs spec'd an equalizing at a fairly modest voltage for 12 to 24 hours when the cells started showing voltage variations outside their limits) And like all batts, one has to set the charging parameters in your charge controller(s). Those are the "care and feeding" parameters I am curious about.

I can't comment about the Rolls versions, but there are other Pb-C AGM batts out there at comparable prices to the "cheap" FLA batts; and they seem to offer higher cycle life, power capacity and current. Don't know if one can really believe these specs fully, but that is one of the questions I have about them.

And I'd agree, in theory flooded will prove longer lived, if only because with equalization you can remove the sulfates which is somewhat limited in AGM or gel batts. However, again if you believe the literature, the use of carbon in the Pb-C batts is suppose to deal with the suflating problems, and supposedly that is why they can claim number of cycles approaching the LiP batts, roughly 2x the FLA cycle counts. Again, I am not saying this is so, just asking if anyone has seen anything to confirm or disprove it.

Anyone have any experience with Pb-C batts they can comment on?
 
Top