Electric Bikes and Electricity: Charging, Consumption, Costs

Updated on 08/18/2023

What are electricity consumption, charging possibilities, real energy costs of charging an ebike battery?

• Where to charge an e-bike battery
• Charging an ebike with solar panels
• How to charge an ebike battery
• Energy consumption by charging

Where to charge an e-bike

Charging at home

The temperature of the room or garage where the battery is charged shouldn’t be inferior to 10°C, or 50 °F nor superior to 30°C or 86 °F, in both cases the battery charging time and even the battery duration in the long run would be, although slightly, affected. Observing this and other precautions, like storing it with around 40% of charge, can even extend your battery life.

Charging an e-bike with your car or camper battery

You can buy an ebike charger for your car cigarette lighter, but there are also transformers 12V to 220V that can be plugged directly into the cigarette lighter or into any car battery, capable of providing at least 300W/h, what is mostly sufficient for an ebike charger. Nevertheless, these universal chargers don’t always work with all ebike batteries. If your battery has 500 watts, it needs roughly 550 watts to be charged, considering that a 10% depletion is normal while charging.

Can charging an e-bike battery exhaust a car battery?

Consider that a car battery has about 50 Ah to 120Ah, whereas an ebike battery can have 8 to 20Ah. If we multiply 12V,  which is the battery tension, for the batteries amperes, we obtain the exact battery wattage, anywhere from 600W to 1400W. Still, energy delivery duration is to be considered. The average car battery has a 50Ah hour capacity if it can sustain 5Ah for 10 hours, which amounts approximately to 600Wh (50Ah x 12V). Now, the average ebike battery can be fully charged at 4Ah/hour in three hours. Therefore, most car batteries have got enough juice to fully charge most ebike batteries, the latters having a capacity going from 200W to 1,000W. Nevertheless, if our car battery is a little weak or is not fully charged, it is better to use it to charge the ebike battery only partially. An alternative is to let the engine run during the charge, in order to enable the alternator to charge the car battery. Anyway, reckon 4 to 10 minutes for an alternator to recharge the car battery. Needless to say, this way of charging is useful for emergencies, like blackouts, or if you are camping in the nature.

Charging an ebike with solar panels, even on the go

There are several photovoltaic panels that are portable and capable of delivering even 220V electricity. Just take into account the power of the solar panel, in order to timely charge an ebike battery it should be at least as broad as a small laptop. The wattage delivered by solar panels can decrease even by 90% during cloudy days. Also, check out voltage and amps of the solar panel, and last but not least, the compatibility of your ebike battery charger connections with those of the solar panel.

Charging at bars, restaurants and private homes

Whenever you have a meal or a drink in a restaurant or a bar, you could kindly ask the waiter to show you a plug for charging your battery. Some fast foods are even equipped with free plugs for their customers. In the end, if you’re really stuck in the middle of nowhere with an exhausted battery, you can always ring somebody’s bell and beg for some juice… That shouldn’t be a habit, but sometimes it can even be funny.

What about EV chargers?

Some EV chargers are equipped with a domestic type socket. Provided that your ebike battery charger can withstand the tension, which is normally higher than at a private house, you can charge your ebike battery at a public electric car charger.

Ebike public chargers

They are an excellent solution when we are on the go, the free one in the photo is in Italy.

How to charge an ebike battery

I further illustrated charging an ebike battery in a recent post, where we suggest to never discharge it under 25% nor chrge it over 90%. We should just consider that, if a battery has been heated by external temperature and or extended usage, we should better wait at least 10 minutes before charging it, least we accelerate its wearing or even risk its definitive failure.

Some people think that it’s better to avoid charging your electric bike battery too frequently if it’s not necessary, because according to battery manufacturers, Lithium-ion batteries have a certain number of charge cycles before their capacity starts to degrade.

I disagree, because:

• with charge cycles manufacturers intend a complete charge, from 5% to 100%
• in my experience, with all my lithium ion batteries (cars, smartphones, ebikes) two charges of 45% each use the battery less than a charge of 90%, for instance because they overheat the battery much less
• if  small charges used the battery like a complete cycle, cars and ebikes that recharge the battery by braking would wear off their batteries incredibly fast.

The slower we habitually charge our battery, the longer its duration. Unless needed, I wouldn’t use our charger with more than 4 Ah.

Energy consumption by charging

How many watts does an ebike charger need to fully charge an ebike battery, e.g. a 500 W model? One would guess, obviously 500 Watts. Well, it’s not so simple. Indeed, every time electricity travels through copper wires, connections, sockets, electrical devices, and so on, there is some depletion. According to autobest.org, a prestigious organization & european auto jury established by leading motoring writers coming from eight countries of the European Union, a Volkswagen ID 3 depletes 5.9% of electricity when charging, a Citroën e-C4, 11.4%, a Honda E an appalling 27.10%. Although they are cars and not ebikes, the batteries are quite similar, always Li-ion, so we can expect similar depletions.

Just consider that, if your charger gets quite warm while charging, that heat is produced by the electricity that should charge your battery. Moreover, many batteries are designed to keep always 5% of their capacity stored, sometimes even 10%, so a 500W battery could receive at most 475 W per charge, regardless of what the charger consumes.

Cost of charging an ebike battery

We can deduct from the above-mentioned data, that the energy cost of riding an ebike is somewhere between 0.2 and 0.3 cents of dollar or euro per kilometer. Indeed, a 500 W battery can provide at least 70 km range on average, so if you reckon 600 Watts consumption to charge it, at the price of $0.24 per kilowatt, we get a cost of 14,4 cents of dollar per charge, which for 70 km results in $0.2 cents per kilometer.