Re-celling your e-bike battery yourself: is it possible?

An e-bike is ideal if you want to cycle longer distances and be able to rely on your battery. Few things are more annoying than coming to an unexpected standstill because your battery no longer works properly.

Re-celling your e-bike battery means that the inside of the battery is replaced. People sometimes use the word for fully charging and discharging the battery, but that is not a cell replacement, and it does little for how the battery works or how long it lasts. In the long run you will notice that your battery still does not cover enough kilometres.

There are three things we come across most often.

The BMS goes into fault mode. With many brands the battery management system notices that different cells have been fitted and locks the battery. Sometimes that can be solved in software. Often it cannot.

The cells are not balanced. New cells all have to be at the same voltage before they are connected in series. If they are not, the weakest cell drags the rest down and within six months you have the same problem again.

The connections are not sound. Cells are joined with a spot welder, not with a soldering iron: soldering puts too much heat into the cell. A poor connection gets warm under load, and with lithium, heat is where the trouble starts.

On top of that, a cell replacement is a few hours' work even for an experienced technician, and without a capacity test afterwards you do not know what you have ended up with.

Not sure? Have your battery inspected first. Then you know whether the cells really are the cause before anything is replaced.

In almost every case you can take the battery out of your bike yourself. You do that with a separate key, or sometimes simply with the same key as your lock. On some bikes the battery is held in place by a click system, but on most bikes it sits in a slide rail.

A cell replacement at KWS Seuren costs from €300. Most e-bike batteries come to between €350 and €500, with the average around €425. That covers everything: the intake test, new A-grade cells, a check of the BMS, a full charge and discharge cycle with your own charger, and a capacity test. You get the result of that test.

You get a 2-year warranty on the work and the materials. If you do it yourself, you do not have that warranty, and with many brands the warranty on the bike lapses as well.

Look up your battery and see what is possible for your model, or first read exactly what a cell replacement involves.

If you are thinking of having your e-bike battery re-celled, there are a few things to keep in mind. First, choose a reliable specialist with experience in re-celling batteries. Always ask for a diagnosis beforehand, so that you have a clear picture of the condition of your battery and of what the cell replacement will cost. It also counts in a company's favour if it has worked on many different brands and types of e-bike battery. That raises the chance of a successful cell replacement and of a battery that lasts for years to come.

Before you decide where to have the work done, look at two more points. The first is the technical expertise of the company. The second is customer service: good communication and clarity about the cell replacement process are essential.

Thinking of re-celling your e-bike battery yourself? Send it to us instead.

For Gazelle batteries, for example, we have developed our own software, which lets us reprogram Gazelle Innergy batteries and update them to the correct capacity. Some Innergy batteries marked "Assembled in EU" cannot be re-celled; see which batteries we cannot re-cell. We do not recommend re-celling your Gazelle Innergy battery yourself.

We do not usually recommend re-celling your e-bike battery yourself. You need to know what you are doing, because if something goes wrong it soon becomes more expensive. If you have us re-cell your battery, you are sure of a 2-year warranty and your battery is in experienced hands. We know the problems from experience, and we know how best to solve them. Would you like to know more about the options for your e-bike battery? Have a look at our e-bike battery cell replacement page.

Apart from the risk and the complexity of doing a cell replacement yourself, the cost deserves a look as well. A new battery can cost considerably more than having your current battery re-celled. With an e-bike battery cell replacement at KWS Seuren your battery performs like new again, often for well below the price of a new one. Because we diagnose the battery thoroughly beforehand, we can estimate exactly what is needed to restore it. So you know where you stand before any work starts. Having your battery re-celled by a specialist is therefore the safest choice, and often the cheapest one too.