Battery Voltage

[FrodoBaggins]

Hi All

I have a 48V battery (17.5AH). I am running it on a Tongsheng TDSZ22.
I dont trust the battery capacity measure on the display so have been using a voltmeter

When fully charged the battery is at 54V
Yesterday I did a 21 mile ride and the battery is at 51.7V
I could say that yesterday would be a typical ride, regarding effort and terrain/ gradient.

I have read that most 48V batteries operate a cut off of around 40V. Giving me 14V to play with

So is there any logic in the maths that could work out around 100 miles? based on using 20%
I assume it would be less than that seeing as at the lower voltage there would be less power. But could I realistically expect maybe 80 miles?

Or is this a nonsense thing to say?

BTW I do cycle quite a bit myself on these runs

 

[vfr400]

Hi All

I have a 48V battery (17.5AH). I am running it on a Tongsheng TDSZ22.
I dont trust the battery capacity measure on the display so have been using a voltmeter

When fully charged the battery is at 54V
Yesterday I did a 21 mile ride and the battery is at 51.7V
I could say that yesterday would be a typical ride, regarding effort and terrain/ gradient.

I have read that most 48V batteries operate a cut off of around 40V. Giving me 14V to play with

So is there any logic in the maths that could work out around 100 miles? based on using 20%
I assume it would be less than that seeing as at the lower voltage there would be less power. But could I realistically expect maybe 80 miles?

Or is this a nonsense thing to say?

BTW I do cycle quite a bit myself on these runs

The discharge curve isn't quite linear, so it's difficult to extrapolate. Roughly, when you get down to 48v, you're about 60% of the way down as long as you don't run too much with high power after that, otherwise maybe 65%. If you pedalled exactly the same over the same route for the rest of the battery, I'd estimate a range of 65 to 75 miles; however, your legs would get tired after a couple of hours, so probably something like 55 to 60 miles unless you're very fit.