Batteries
16 Batteries are located in the bed of the pickup truck.
I used 20 6-volt golf cart batteries. These are traction batteries designed to move a vehicle. They also have a thicker lead plate than a conventional sized 12 volt automotive starting batteries. A starting battery conveys a huge amount of current for a short time, but for an electric vehicle, we need a smaller amount of amps for a longer duration.
Another lead acid battery is the sealed type. These do not allow the battery cells to be replenished. However, they are safer to install inside the car, because no acid can spill from the battery. I went with the flooded traction battery because they are less expensive, and they you to make the mistake of overcharging them. However, the sealed ones do better in colder weather. I was able to keep my batteries warm because I parked in a heated garage every night.
The batteries will last longer if you discharge them less during their use.
Each battery type is different, but this curve (Kordesch, 258) shows that generally you can have a significant increase in battery life if you keep the batteries from fully discharging.
I have driven over 4,000 miles in about 6 months using my current set of batteries. Almost every day I charged them twice. So I have cycled my batteries over 360 times.
About a dozen times, I ran the batteries down to 100% discharge. The vehicle lost power, and I could only drive less than 5 mph. I would stop the truck, wait 10 minutes, and then there would be more power available.
There are other battery technologies that use Nickel Metal Hydride, Nickel Cadmium, and Lithium Ion. However, after you do a cost analysis, it would be better to wait for these battery types to come down in price before using them.
I also have 4 additional batteries up front in the engine compartment.
Here you can see the electric pump and reservoir for the brakes (center, rear).