DIY Electric Car Forums banner
1 - 1 of 1 Posts

53 Posts
Hi lou-ace

Well done with getting the truck on the road :)

As Ev-fun metioned, there is a major difference between an OCV (open circuit voltage- without load) and CCV (closed circuit voltage- under load)

A batteries IR (Internal resistance) is equal to the difference between OCV and CCV divided by the load.

The equation is not linear since a batteries IR always becomes greater as the battery becomes discharged, due to the lowering of the CCV. The OCV can remain constant whilst the CCV drops therefore the difference between the two increases, hence IR increases.

The OCV will not drop significantly untill roughly 75%dod.

To make a accurate calculation you need to consider discharge time as well as other things such as temp etc..

I couldnt find much info on the crown batteries but i expect they are simular to the trojan t-105s so have made calculations based on this.

So lets assume you discharge the batteries in 1hr. Using the Batteries Reserve capacity we can work out the 1hr rating of the batteries is around 127ah the peukerts exponent= 1.23

127*120v= 15240wh pack total usable energy in 1hr

say you average 40mph in the 1hr duration which means you would have travel 40miles.

15240wh/40miles = 381wh per mile or 3.1ah per mile. I think figure would be more for a truck like yours though.
1 - 1 of 1 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.