Have a look at http://www.secbattery.com
. Their red top AGMs should be of interest to EV owners. I know forum member dillond666 has some and I used some of their front terminal gel cells in my volvo. They are the only battery manufacturer that actually publishes detailed discharge data for their cells so you can see the actual capacity for say 50, 80, 125 amps etc.
I presume its the same as http://www.secukbattery.co.uk/
who are the UK distributers
if they are then I had a bit of a failure with them, wanted to buy 5x 12v blocks but never really got anywhere with them
they were (dunno if they still are) supplying the green power race folk, got a great quote the other year from them at the green power finals stand but when I went to try and order them the price bizzarely went up by a considerable amount, then they wanted delivery on top, so as green power is based near me asked if they could put them on the next deliver down to them and share costs or something, but that never came to anything so gave up with the company
it was like they werent interested in selling batteries