One of the questions that are most often asked by people new to the world of ebikes is: how long does the battery last? Modern lithium batteries have a much better range than older lead-based batteries used until a few years ago: nowadays, the range of an ebike is usually more than enough for everyone.
The range of an ebike is most often measured in kilometers. This unit of measure makes sense if you do not have to pedal over an important elevation gain, i.e. if uphill sections are short and not very steep. However, when climbs are long, and your trip has a high elevation gain, the latter is the best unit of measure of an ebike’s range. We have decided to do a test exactly in order to better explain these issues: what is the battery consumption of a Bosch ebike after 1000 meters of elevation gain? Let’s go find out.
The ebike we chose for this test is the one we are testing these days, a Cube Hybrid SUV Race 500 27,5. The ebike has a standard Bosch Performance Line motor (not the new CX version), coupled with some very interesting componentes: a belt drive, and an automatic and continuously variable gear shifting system, the Nuvinci N380, completely integrated with the Bosch ebike system through the H|Sync technology. The battery is the new, 500Wh Bosch battery. This is a high-range ebike, sporty in feeling, with components of very high quality.
(Over the next few weeks, we will publish an in-depth article both on the ebike itself and on the Nuvinci N380 H|Sync). EDIT: here is the link to the NuVinci N380 test.
In order to test the battery consumption after 1000 meters of elevation gain, you have to go in a mountainous area. We have chosen the Monti Simbruini Natural Park in the Latium region (not far from Rome, Italy); these days, it offers some wonderful views thanks to the autumn colour of its trees. We started from a spot right above Subiaco, at 450 meters of altitude; we then reached Cervara di Roma (1050 meters) and from there Campaegli (1450 meters).
- Date: 31 october 2015
- Temperature: about 13°C (lithium batteries perform at their best with temperatures about 20°C; at 13°C there is a loss of efficiency estimated at about 5%)
- Motor: Bosch Performance Line 2015
- Battery: Power Pack 500 Bosch (actual capacity: 482,4 Wh)
- Assistance level: Tour (the second out of 4; with this level the motor delivers 110% of the power delivered by the cyclist). Please note: it is “only” 110% because the ebike has a hub gear, with a derailleur the motor would deliver 120% of the cyclist’s power.
- Cadence: 75 rpm, a value selected through the Nuvinci H|Sync system
- Surface: asphalt in good conditions
- Ebike’s weight: 21,2 kg
- Cyclists’s weight: 83 kg (including clothes and backpack)
The climb has a regular incline, almost always around 6%. This is ideal in order to better estimate the battery’s range.
First section: 2km – 5,7%
In the first section, about 2 km long, the average slope is about 5,7%. The average speed was 17 km/h.
Second section: 4 km – 4,2%
After a short flat section, the climb continues with 4km at a 4,2% average slope. Average speed has of course gone up, about 23 km/h.
Third section: 12,4 km – 6%
The long, final sector has a rather steady inclination, about 6%. Average speed has settled at about 16 km/h.
Battery consumption after 1000 meters of elevation gain
According to what Bosch says, each of the five LEDs on the Intuvia screen represents 20% of battery capacity. The second LED has turned off at 1240 meters of altitude, after 800 meters of elevation gain. Battery consumption was therefore about 40% (about 200Wh). Because the incline of the climb did not change (nor did the speed), a simple mathematical proportion leads us to understand that 1000 meters of elevation gain consumed about 50% of this 500Wh battery (this was confirmed by the rest of the journey, with the third LED taking quite a long time to turn off).
This result is quite consistent with what other users of the Bosch ebike system have noticed: it takes about 100Wh to pedal over a 400 meters elevation gain. Of course, the range of an ebike is influenced (positively or negatively) by a wide range of factors, whose influence can be very strong, so you might obtain better or worse results than ours.
Very similar data could be gotten with other ebike systems working in a very similar way to the Bosch one, as for instance the Yamaha, Shimano STEPS, Brose or Impulse systems: in all these cases, we are talking about central motors, with 250W of power, based on a torque sensor. Of course you’ll have to make the comparison on similar settings, and therefore with an assistance level which doubles the power delivered by the cyclist. Ebikes based on hub motors and/or with simpler pedalling sensors will give very different results.
Usually it is e-mountain bikers that are more interested in calculating an ebike’s range in terms of elevation gain. It is with e-mtbs that usually the elevation gain is more important than the distance travelled. We will repeat this test with a Bosch e-mtb as soon as we can get hold of one for an in-depth test.
Stay tuned for the Nuvinci N380 H|Sync review, and for the test of the Cube ebike.