An e-bike is one of the cheapest things in the house to plug in. A full charge of a typical battery costs somewhere around 13p to 18p and carries you 30 to 60 miles of assisted riding, so the electricity comes to well under half a penny a mile. Put next to a car, or even a bus fare, that is almost nothing. The number is easy to work out for your own bike once you know the battery size, and there are a few habits that keep both the charge cost and the battery itself cheap over the years.
The short answer. Most e-bike batteries hold between 0.4 and 0.7 kWh of energy. At an example electricity price of 26p per kWh, close to the current Ofgem cap, filling one from empty costs roughly 11p to 20p once charging losses are counted. Charge a couple of times a week and you are looking at £10 to £25 a year. Even a daily commuter rarely spends more than about £45 a year on charging.
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What a full charge costs
The cost of a charge is just the energy the battery takes in, measured in kilowatt hours, multiplied by what you pay per unit. An e-bike battery is small by household standards. A commuter bike might carry 0.5 kWh, which is about the same as running a 2 kW fan heater for fifteen minutes, or charging a phone from flat around forty times over. So even though you plug the bike in often, the amounts are tiny. At 26p a unit, a 0.5 kWh battery costs about 13p to fill, before you add the small amount of energy lost as heat during charging. A bigger 0.7 kWh touring battery lands nearer 18p to 20p, and a compact folding-bike battery of 0.37 kWh comes in under 11p. If you want to turn your own figures into pennies quickly, the appliance running cost calculator does the arithmetic.
Working it out from your own battery
Battery makers usually print the size on the pack or in the manual, but not always in kilowatt hours. More often you get the voltage and the capacity in amp hours, for example 36V and 14Ah. Multiply those two together and you get watt hours: 36 times 14 is 504 Wh, which is 0.504 kWh. A 48V 10.4Ah pack works out at about 0.5 kWh the same way; a 48V 14Ah pack is around 0.67 kWh. Once you have the kWh figure, multiply by your unit rate. The guide to what a kWh is explains the unit if any of that feels unfamiliar.
One wrinkle: you rarely charge from completely empty, and the charger draws a little more from the wall than ends up in the cells, because some energy is lost as heat. For a rough real-world figure, add about 10 to 15 per cent to the battery's rated size. So a 0.5 kWh battery charged from near flat pulls closer to 0.57 kWh from the socket, which at 26p is a shade under 15p. The cleanest way to measure it exactly is a plug-in energy monitor between the charger and the wall; leave it running through a full charge and it shows the units used and the cost.
Cost per mile, and how it compares
Range is where the e-bike really pulls ahead. A 0.5 kWh battery that takes you 40 miles on a middling assist level has cost about 15p for the trip, which is under 0.4p a mile. That is the figure worth holding on to, because it makes the comparison stark. The table below uses illustrative prices to line the e-bike up against the usual alternatives.
| How you travel | Example cost per mile |
|---|---|
| E-bike (home charging) | ~0.3p to 0.5p |
| Electric car (home, off-peak) | ~2p to 3p |
| Electric car (home, standard rate) | ~6p to 8p |
| Petrol car (~45 mpg) | ~14p to 16p |
Illustrative figures at an example electricity price of 26p per kWh and petrol around £1.40 a litre. Your own costs vary with the specific bike, car, tariff and fuel price.
A petrol car costs you something like thirty to forty times as much per mile as the e-bike. Public transport does not necessarily win either: a single bus fare of a pound or two for a short hop often works out dearer per mile than charging the bike, and the bike is ready the moment you are. For the car side of that comparison in more depth, the cost of charging an electric car at home and running an EV against petrol both go further.
What pushes the figure up or down
The headline cost is small, so the things that change it only ever move it by pennies. Still, they explain why your range and spend differ from the next rider's.
- Assist level. Riding in the highest power mode drains the battery fastest, so you charge more often. Dropping to a lower assist on the flat stretches the range a long way and costs you only a little extra effort.
- Hills and headwinds. Climbing and fighting the wind both pull hard on the motor. A hilly commute can halve the miles you get from a charge compared with a flat one.
- Total weight. A heavier rider, a loaded pannier or a child seat all mean the motor works harder. The effect is modest but real on a long ride.
- Tyre pressure. Soft tyres add rolling resistance and quietly eat range. Keeping them pumped up to the pressure on the sidewall is a free way to get more miles per charge.
- Cold weather. Lithium batteries give up some of their usable capacity when they are cold, so a January charge may not go as far as a June one. The battery recovers as it warms; it has not lost anything permanently.
The charger, and the small waste worth avoiding
The charger itself uses a trickle of power even when the battery is full, and many chargers stay slightly warm if you leave them plugged in and switched on. It is a very small amount, pennies over a year, so it is not worth losing sleep over. The sensible habit is simply to unplug once the light turns green, which costs nothing and also happens to be better for the battery, as the next section explains. There is nothing to gain from an expensive smart plug purely for an e-bike charger, though if you already run one for off-peak timing, by all means use it.
Looking after the battery so it stays cheap
The running cost of an e-bike is trivial. The battery is the expensive part, often a couple of hundred pounds or more to replace, so the real money is in making it last. A few habits help.
- Avoid sitting at 100 per cent or at empty. Lithium cells are happiest in the middle of their range. Charging to full right before a long ride is fine, but leaving the pack at 100 per cent for days on end ages it faster. If your charger or app offers an 80 per cent limit for everyday use, it is worth using.
- Do not store it flat. A battery left empty for weeks can drop so low it will not take a charge again. For winter storage, leave it around half to two thirds full and top it up every month or so.
- Keep it out of extremes. Charging a freezing battery or baking it in a hot shed both shorten its life. Room temperature is ideal.
- Charge indoors and attended where you can. This is a safety point as much as a cost one. Use the charger that came with the bike, charge somewhere you would notice a problem, and do not leave it charging overnight unattended.
Cutting the cost to almost nothing
You are already paying a few pence, so there is not a great deal left to save, but the keen can push it lower. If you are on a time-of-use tariff with a cheap overnight window, charging the bike then costs a fraction of the daytime rate; the same logic that applies to an EV applies to the bike, covered in time-of-use tariffs explained and the best time to charge. If you have solar panels, charging on a sunny afternoon means the electricity is effectively free. And some workplaces let staff charge for nothing, which turns the commute into zero-cost miles. None of this is necessary to make an e-bike cheap, since it already is, but it closes the last gap.
The bottom line
Charging an e-bike costs about 13p to 18p for a full battery and takes you a good way on it, so the electricity works out at well under a penny a mile and under about £45 a year even for daily riders. Work out your own figure by multiplying the battery's voltage by its amp hours to get the kWh, then by your unit rate, and add a little for charging losses. The spend is so low that the sensible focus is the battery's lifespan rather than its charge cost, so charge gently, store it part full, and keep it out of the cold. For the same sums on other small devices, the cost to charge a phone runs through the method on an even smaller battery.
Common questions
How much does it cost to charge an electric bike in the UK?
Roughly 13p to 18p for a full charge of a typical battery at an example rate of 26p per kWh, close to the current Ofgem cap. Most e-bike batteries hold 0.4 to 0.7 kWh, and filling one from empty uses a little more than that once charging losses are counted.
How do I work out the charge cost for my own e-bike?
Multiply the battery's voltage by its capacity in amp hours to get watt hours, then divide by 1,000 for kilowatt hours. For example 36V times 14Ah is 504 Wh, or about 0.5 kWh. Multiply that by your electricity unit rate, and add about 10 to 15 per cent for charging losses.
Is an e-bike cheaper to run than a car?
By a wide margin. An e-bike costs around 0.3p to 0.5p a mile in electricity, against roughly 14p to 16p a mile for a petrol car and about 6p to 8p for an electric car on a standard home rate. The e-bike is often cheaper per mile than a bus fare too.
Does leaving the charger plugged in cost much?
Barely anything, a few pence over a year, because the charger only trickles power once the battery is full. It is still worth unplugging when the light turns green, mainly because sitting at 100 per cent for days ages the battery faster than the electricity ever costs.