2013 txt 48, six 8 volts to four 12 volts question

[yurtle]

Disregard. Missed voltage difference.

[JohnnieB]

Originally Posted by Kramlinck1

So if a 12v us battery is 110min @56 amp and a trojan 8v is 117min @ 56 amps. How do you know the overall runtime of a whole pack?

The US Battery brand battery is probably a model US 12RV XC2 which has a 155AH rating at the 20hr rate.

The Trojan brand battery is probably a model T-875 which has 170AH at the 20hr rate.

The batteries are connected in series to get 48V, so the runtime is the same as it is for an individual battery. You never want to discharge the batteries below 50% SoC (State of Charge), so the runtime is half of the runtime rating and theoretically you'd get about 55 minutes with the 12V batteries and about 58.5 with the 8V batteries. However, the overall average amp draw is going to be higher than the 56A used in the ratings, so the difference will be greater due to Peukert's law. (The higher the discharge rate, the less the storage capacity.) Best guess is about 10% difference between the two batteries mentioned.

If you want more runtime, go to a higher AH 8V battery, or use a 8x6V 48V pack.