A friend of mine bought a secondhand Commencal eMTB that has a Shimano 504WH battery. Yesterday he did a 13KM spin with 900M of climbing and it was nearly out of juice. He weighs about 95KG with his gear and he used a mix of eco (flat/downhill) and trail (climbing) modes.
To counter this, I used the same bike last week and managed to get about 38KM/1250m of climb using only the eco mode. Note there would have been at least 10KM of riding on roads. I weigh about 20KG less than him so that would have an impact. The temperature was similar on both days.
Would this be something you'd expect or could the battery have degraded and if so is there a way to test the efficiency of the battery? What other factors would impact the battery? I presume the faster you climb, the more juice you use? Does the gear (high/low) make a difference too?
Thanks in advance.
The battery is probably fine. Higher assistance and heavier rider uses more energy resulting in less range. Some bikes have apps which will give you lots of data on this.
If you fully charge the battery and put it into the bike, the range in eco mode in km is roughly the battery health as a percentage. When new, it should be about 100km.
Or take it to a Shimano Steps centre and ask them. They can plug it into a laptop.
ST Unlocker will also tell you the battery health, but if Shimano / Madison know you've used it there's no warranty.
Motor efficiency increases as rotational speed increases (to a point)
So depending on the internal gearing in the motor and the gear you use, you could make a noticeable difference.
Tyres, rider weight, cadence etc all affect battery performance.
Was he mostly in turbo? That will make short work of the battery.
It's winter, wet and muddy out there, was out at the weekend in FoD, got 22 miles, 1100m of climbing and ran my 625wh battery dry, it's just riding slush doesn't help, summer you can get way more, for comparison i did 20 miles today, about 300m of climbing and used 30% of the battery, it was just i was riding hardpack and roads (and headwind was high!), with a lot less climbing, but you take that same bike out on dry roads, you'll get loads of miles, just understand your range on certain conditions and surfaces.
On Saturday I did my local loop with a mate. I ran my e-bike (a Spesh Levo) on Eco mode at a fairly high cadence around the 24km, 400m climbing, muddy, 90% off-road loop to keep myself warm as he was on a regular bike. I think my battery was sitting with around 68% left at the end. I currently weigh in at around 105kg.
Last night, after a particularly shite day at work, I headed out in the dark, wind and rain. I did the same loop, but much angrier, so had the bike in Trail most of the loop and even Boost mode a couple of times. I got home with about 46% of the battery left.
So, try smiling when you ride, your battery might just last longer!