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Some folks are anti-flooded and others are anti-AGM and there is tons of information out there supporting or decrying each in an EV application. As such I can't make up my mind about which way to go.

The main things that concern me with flooded batteries are:

- Issues with not having the full Ah rating available to me (I'm still not clear on this one).
- Short lifespan.
- Trying to do maintenance on batteries mounted in a tight space.


The main things that concern me with AGM batteries are:

- Smaller Ah ratings (though some say they actually discharge more Ah than flooded, which I don't understand).
- They cost 2.5-3x that of flooded while reporting only 2x the lifespan.


What are your thoughts?

I don't know enough about either technology to provide information you don't already know, but I'd be very interested to hear this discussion as well. Any takers?

There is a brief comparison of AGM versus gelled and flooded batteries at the following website:

http://www.windsun.com/Batteries/Battery_FAQ.htm

My EV uses 12 volt AGM batteries (Discover EV31A-A). The nice thing about them is that they are maintenance free. However, like all lead-acid batteries, they offer poor performance in cold winter weather. My range drops at least 66 percent when the temperature gets down below 25 degrees F.

Eventually I may go to Lithium Iron Phosphate batteries, or maybe the EESTOR batteries if EESTOR ever gets them to market. Cost is a factor, though. The lithiums, and probably the EESTORs, are very expensive.

Thank you for the link, Jimmy, but what I'm hoping for is a direct comparison that shows something like, "I used flooded batteries for this long and this is what they did for me. Then I used AGM batteries for this long and this is what they did for me.". Real-world application comparisons.

Another consideration: many of the old hands on the EVDL will tell new EV owners not to spend much money on their first pack. Why? Battricide. Noobs tend to kill their first packs prematurely as they learn how best to drive / charge / balance them.

I can vouch for this. I've already murdered more than a handful of batteries myself. (Fortunately, they were free, and we were given enough that there are spares.)

That would seem to suggest choosing flooded for your first pack for 2 reasons: 1) they're more forgiving of abuse, and 2) cheaper to replace when the time comes.

I doubt if EV owners will ever be satisfied with a lead-acid battery pack, whether it is the AGM type or whatever. They just don't have the duration or performance. Hopefully the lithiums will become affordable.

I'd put my money on Firefly becoming accessible to the DIY EV crowd before lithium, personally.

Thank you for the feedback, Metro. Those are solid ideas and make perfect sense.