How To Look After Your E-Bike’s Battery

(Image credit: Unknown)

Bike maintenance, like DIY, is one of those things that’s almost always a little more annoying and time-consuming than you expect it to be. However, the good news is that looking after an e-bike battery involves very little work. In fact, the key is mostly not doing certain things that can slash the life of your battery.

For an explanation of best practice for keeping your e-bike battery purring, we spoke to Dan Parsons, director of operations at e-bike retailer Fully Charged.

How long should an e-bike battery last?

Lithium batteries are typically quoted as lasting a number of cycles, because it depends on how often you use them. A lithium battery will normally last in the region of 500 to 750 cycles, which is a full charge, from empty to full to empty again.

And at that point they’re not dead – that’s when the battery drops to about 80% of its capacity, After that point you’ll notice a reduction in power and range. From our experience you’re looking at about two to five years.

Should you let it go completely flat before charging an e-bike battery?

Lithium ion is like your smartphone battery technology. It doesn’t matter if you plug it in at 0% or 95%.

Does it count as a cycle if you plug it in when it’s 90% full?

No – if you’re only using a tenth of the battery capacity you’ll get ten times that in a cycle.

What factors can shorten the life of a battery?

What batteries absolutely detest is being run flat and then left for any length of time. The chemistry of the battery doesn’t like that, and that can kill them a lot quicker.

Overheating is also bad. It’s just a load of chemical reactions going on inside the battery, and if you heat them up they occur faster, so they degrade quicker. Don’t leave them in hot cars. A black bike in the boot of a car in the height of summer might reach the temperature where the battery will shut itself off.

Does the cold affect them as well?

You will notice a drop in range in the winter, because those chemical reactions are happening a little slower. It’s a bit like when explorers go to the South Pole – they shove their camera batteries in their armpits to keep them at a warmer temperature.

In the winter you might want to bring the battery inside to charge it overnight, so it’s kept at room temperature. When you’re using it, it naturally warms up in any case but it takes a while, so if your ride is short it might not warm up and reach its optimum temperature.

Is there any risk to riding in the rain?

Road spray or torrential rain is fine – just don’t go and jump into a swimming pool with it. Some brands will advise you to use the motor more in the wet because the warmth it generates can evaporate any moisture that does build up on them, but there’s no issue really.

Fully Charged is one of the leading stockists of Bosch eBike Systems in the UK. To learn more about Bosch ebike Systems visit, where you can also find a downloadable guide (PDF) on how to look after an e-bike battery

Nick Harris-Fry
Senior writer

Nick Harris-Fry is a journalist who has been covering health and fitness since 2015. Nick is an avid runner, covering 70-110km a week, which gives him ample opportunity to test a wide range of running shoes and running gear. He is also the chief tester for fitness trackers and running watches, treadmills and exercise bikes, and workout headphones.