Electrathon rules allow up to 73 pounds of lead acid batteries.
Voltage and number of batteries are not specified.
They must be Gel or AGM, so there is no possibility of an acid spill in the event of an accident.

Most teams run a 24 volt system made up of two 12 volt Optima batteries, each weighing around 36 lbs.
We decide to try running four Deka XTX18L. Each battery weighs 17.5-18 lbs, so we will have a 48 volt pack weighing 70-72 lbs.

There is extensive testing data on the capacity of the Optimas.
The Optima Yellowtops are rated at 1,152 Watt hours at the 20 hour discharge rate.
At the one hour rate which is closer to what they will see in competition, the Optima Yellowtops should have around 750 Watt hours (375 Watt hours per battery).

The Dekas are rated for 960 Watt Hours (240 per battery) when they are discharged over 20 hours (the 20 hour rate). Lead acid batteries deliver less power when discharged at a faster rate . We hope they will be competitive with the Optimas.