Maybe you bought some that had sat on the shelf for a year. Other people who have had those B&B have reported using them for about 5000 miles.

Since you only have 24v, have you thought about buying two 12v Thundersky packs for about $240 ? I assume you are only pulling about 20 amps out of the batteries? If so, Thundersky would be the way to go in my opinion. The cost is just a little more than some good SLA batteries and they'll last a lot longer. Probably 5 years or more.

http://elitepowersolutions.com/produ...products_id=74

You can buy them with or without balancers. I use mine without balancers and they are fine. I charge mine with a regular 12v SLA charger. Only thing you have to worry about with Lifepo4 is the batteries can't go below 2.5v or above 4.2v. I usually charge mine to about 3.7v per cell. Another thing you have to worry about is a damaged cell so you have to check the voltages each time you charge them to make sure the cells are still working okay but aside from that, they are great. I've been using them since January.

You could buy a celllog 8s monitor from hobbyking.com for about $15 and put a small piezo alarm on it to warn you if you ever get below 2.5v per cell. If you want to know more about how I charge them and use them, there is a thread on here called "looking for battery recommendations" .