Interesting. I've considered an optima battery for the same reasons
I was going to get a braille lithium ion battery but at ~$600 the $/lb was not justifiable compared to this Deka that I was able to get for $88 shipped. I spent a total of ~$150 for the battery/autometer trickle charger/braille 8" mount/battery charging posts. The car fired right up on the first try.