Electric Bikes Batteries & Range

Batteries

Our batteries are state-of-the-art lithium technology. Unlike standard lithium batteries ours are lithium-ion polymer, safer and more efficient. When coupled to our advanced battery management systems (BMS) we believe we have some of the best batteries available!

To calculate the capacity of a battery on any electric bike, simply multiply volts (V) by amp-hours (Ah) to give you the number of watt-hours (Wh) in the battery, i.e. 36V x 10Ah = 360 Wh.  The capacity of a battery (Wh) is very important when choosing an electric bike as it lets you know what the range of the bike is likely to be (for a given motor).  The size and efficiency of your motor is obviously also a key factor affecting range.  A 500W motor will use a lot more 'juice' than a smaller motor. The Wisper Li(NiMnCo)O2 36V 15.5Ah battery is one of the most powerful lithium batteries on the electric bike market, producing a massive 558 Wh!!

As an example here are range test results using three of our Wisper 2010 batteries with a 250W motor (the ranges quoted will be bigger with the new Wisper 15.5Ah batteries!).

Voltage

Amp-hours

Capacity

Range

36V

14Ah

504Wh

90 - 119 km

36V

8Ah

288Wh

46 - 71 km

24V

9Ah

216Wh

35 - 51 km

 

As you can see, the smaller capacity batteries give you less distance.  The figures above were taken on a real road with a real rider weighing 74kg (162lbs) on a cold day (10 degrees centigrade) with some braking.  As opposed to a rolling road in a warm factory on which a lot of testing is done.  Always ask under what conditions the range quoted was obtained.  There are a lot of mis-leading ranges being put forward by other brands e.g. quoting long ranges but in low pedal assist settings where the rider puts in 90% of the effort.  

350W Motor Range Test: Last year we completed a battery range test on  Wisper 905SE with the 14Ah battery and 350W motor.  Amazingly, we achieved just over 90km (56 miles) on a single charge ... almost the same as the smaller 250W motor!  This was a great result which demonstrates the effciency of the new motor ... more power, with a similar range.  Again, it should be noted that this ride was on undulating terrain (a total elevation gain of just over 300m) and with regular stopping and starting i.e rather than controlled 'lab' conditions.  The pedal assist was set to 'medium' with a cruising speed of 18-23kmh.  Be aware of range test claims!  Always ask the exact conditions that the test was conducted under, including the level of pedal assist used.  Check out this link where a GPS record of the ride is overlain on a Google map, along with a summary of the ride stats.  For those of you familiar with Vancouver, we completed just over two circuits from Jericho Beach, into and around Stanley Park, and back.  If you hit the 'Player' button on the top right of the site, you can replay the ride.

CLIMB TEST: As discussed below, the size of the hills on your ride will affect the range of the bike.  We thought we'd test this out by riding a Wisper bike up and down Mt Cypress in Vancouver until the battery gave out.  We acheived a pretty impressive 1.3km (1,300m) of vertical climb on a single charge, and 43km total distance ... and this was with a 90kg rider!  We almost made it up and down the mountain twice!  Check out the Youtube video.  As above, this link shows the ride on a map with all the statistics.  We rode up in with the pedal-assist setting on maximum, giving an average speed up the (steep!) hill of well over 20kph.  If we'd set the pedal assist to a lower setting, we would have acheived even more vertical metres.  All credit to the cyclists riding up this hill under their own steam ... its a big grind!  But thats what ebikes do, allow the average punter to ride many more places, without being an elite athlete.

Popular electric bike battery capacities:

Bike

Volts

Amp-hours

Capacity

Wisper 905SE/705SE Li Po

36

15.5

558 Wh

Pedego 15Ah Upgrade 36 15 540 Wh

A2B Li Ion

36

11.4

410Wh

OHM Sport XS750 Li Ion 37 10 370Wh

Ezee Forte Li Ion

37

10

370Wh

Wisper 805FE Li Po

36

9

324Wh

Urban 500 Li Ion

27

12

324Wh

Giant Twist Li Ion

26

9

234Wh

 

Range

The range of any electric bike can vary massively depending on some very simple factors.

Weight:  Not just the weight of the rider but also the weight of any luggage being carried or towed will affect the range you will get from your bike.

Wind resistance:  Have you ever wondered why road racers wear Lycra?  It’s not just to show off!  The fact is that if you were to wear Lycra on your electric bike (I don’t suggest for a moment that you do!) your range would be much higher than if you were wearing a huge overcoat and a nice big set of saddle-bags!

Tire Pressures:  Always keep your tires pumped up to the correct pressure as a firm tire significantly reduces the rolling resistance.  If you have ever had a flat tire you will know this first hand!

Air temperature:  You will get about 15% more range from a battery on a warm sunny day than you would in winter.

Road conditions:  A smooth flat road is much more efficient than gravel or grass for long range.

Hills:  I realise you can come down the hill you just went up without using any power but you would have used a lot less power if you covered the same distance on the flat (see climb test results above).

Battery age:  As batteries get older they start to lose the ability to hold a charge for as long as they did when they were new.  If you are using a 5 year old battery you will not get the same range as when the battery was charged for the first time.

There are of course other factors such as maintenance and wind speed but these are the most important points to remember.