Your electric bike battery is one of the most important and valuable parts of your bike.
Looking after it properly will help you get the best range, the longest lifespan and the most reliable day-to-day performance.
We are often asked about charging, storage, safety and battery care, so this guide covers the most common questions in one place.
Since 2018 we have sold over 20,000 electric bikes, all fully legal for use on roads and cycle paths.
In that time, battery failures have been extremely rare. Bosch batteries are covered by a 2-year warranty and up to 500 full charge cycles. Yamaha provides a 2-year warranty on all electrical components.
We have never had a report from one of our customers of a battery malfunction leading to a fire.
Charge at room temperature, avoid letting the battery fully discharge, use the correct charger, and store it partly charged if you are not using the bike for a while.
Battery basics
These are the key things most riders want to know first.
The bigger the battery capacity, the bigger the fuel tank. We supply bikes with batteries ranging from 250Wh to 800Wh.
On most modern bikes the battery is integrated into the frame. Some bikes can take dual batteries or a range extender for longer rides.
On the majority of bikes we sell, yes. The battery can usually be removed easily for charging, storage or transport.
Range and charging
What range will I get?
There is no single answer because range depends on assistance mode, terrain, surface, temperature, rider weight, tyre choice and tyre pressure. If your bike has a range display, it will adjust as you ride and give you a useful live estimate.
You can use the Bosch range calculator here.
What happens if I run out of charge?
You can still pedal the bike like a normal bicycle. It is best not to run the battery fully flat, so if it is getting very low, switch the assistance off before it reaches zero.
How long does charging take?
A full charge usually takes around 4-6 hours depending on battery size and charger type. If you top the battery up regularly, charging may only take a couple of hours or less.
Best practice for charging
Charging habits make a real difference to long-term battery health.
Charging regularly at room temperature is best. If you are not using the bike for a while, store the battery at around 60% charge and check it every few weeks.
No. Charge during the day when you can unplug it once it is full. Do not leave it charging when you are out of the house.
Always use the correct manufacturer-approved charger. If it is damaged or worn, replace it with an official charger from a reputable seller.
Temperature, storage and general care
Always charge your battery at room temperature. Lithium-ion batteries do not like being charged or stored in very hot or very cold conditions.
If you have been riding in very cold or hot weather, allow the battery to return to room temperature before charging. This may take an hour or so.
Batteries should be charged on a hard, flat surface, out of direct sunlight, away from heat sources, and in a well-ventilated area rather than inside a cupboard or enclosed space.
Electric bikes are designed to be ridden in the rain, but they are not waterproof. Avoid exposing the battery to excessive water, and dry the contacts if the bike gets very wet to reduce the chance of corrosion.
Lifespan, charge cycles and replacement
How many charge cycles should I expect?
Around 300-500 full cycles is a conservative expectation, but careful charging habits can significantly extend that. Bosch states around 8-9 years or roughly 1000 full charge cycles in normal use.
How long will the battery last overall?
You should comfortably get 6-7 years of normal use, and often longer. Over time, the battery will still work but gradually lose capacity, so range will reduce.
How much does a replacement cost?
A typical replacement battery costs between £350 and £800 depending on the type and capacity.
Only buy an official replacement battery from an approved retailer.
More common battery questions
Only if they are like-for-like on the same system. Some systems allow different capacities, but the battery style must still be compatible.
Yes. It is strongly advised to remove the battery when transporting your bike.
In-frame batteries have the smallest footprint. Bosch batteries weigh around 2.5kg and are among the lightest on the market.
Bosch and Yamaha systems both come with a 2-year battery or electrical component warranty, depending on the brand.
Sometimes. If it has entered sleep mode, hold the power button on the battery for 10 seconds and then try charging again.
In practice, no. If the battery is damaged, do not continue using it. Opening a battery is dangerous and will void the warranty.
Battery safety
Inspect your battery regularly for signs of external damage, especially if it has been dropped or knocked.
If a battery begins to smoke, move it outside as quickly as possible if it is safe to do so. You can use a suitable fire extinguisher if you feel confident, but call 999 if the situation feels dangerous.
You can read more about electric bike safety here.
Still got questions about your battery?
If you need help with battery care, charging or replacement options, our customer service team will be happy to help.