Battery Range Test

[faphillips]

Having now equipped my Brompton Nano so it will run on either the 7Ah Li Po battery it came with or a Bosch 36v 2.6 Ah powertool battery I am keen to undertake a comparative test. Some of you may recall that A to B managed 47.9 miles on a single charge of the 7 Ah battery which included some hills -although many readers have assumed the tester pedalled rather more than they should have, especially as the bike is so easy to pedal.

The question is what is a fair way to test battery range? Should it be over a set course with no pedalling or should one pedal as well? If one pedals how can one be sure that the same pedal asistance was given to each battery?

The alternative I gues is just to do my normal journey (it's the same every day) and run both batteries from full charge to flat. Suggestions appreciated.

Another question regarding these batteries and the battery condition indicator. The twist grip throttle has 3 LEDs Green, Amber, Red. All 3 remain lit on the 7 Ah battery almost regardless of its state of charge - although I havent managed to run it flat yet. On hills, only the red LED remains alight. The Bosch battery on the other hand will only show all 3 LEDS lit at standstill and as soon as I ride off I am down to just 2 and after a couple of miles I am down to 1 whilst riding, even though 2 of the 3 battery's own LEDs reamain alight. Thus far I have only ridden about 4 miles on the Bosch battery and that reduced it from 3 of its own LEDs to 2. Why the different performance and xoe this suggest that the bosch battery isnt going to have the range I had hoped for (9 miles).

Francis

 

[flecc]

A fair test is really impossible on an e-bike Francis, simply because the rider input cannot be accurately specified. A to B's figure definitely was more the rider, since they reported an average speed of well over 16 mph with a motor that drove only to 13 mph most of the time. Given their moderate territory, I know from experience that the motor wasn't doing much or anything most of the time. For example, on my small wheel Q bike with motor that drives to around 16 mph, plus or minus 1 mph depending on battery level, the average is typically around 15.5 to 16 mph.

This is why on the Kalkhoff test I specified the various circumstances in very full detail and the resulting ranges, rather than just stating a bald figure which can't possibly be right for every rider and every territory, therefore being fairly useless.

I'd suggest you just choose the riding style you feel comfortable with, on your normal journey.
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