E-bike battery service: How to fix rattling noises in the battery compartment

1 Washing: Clean the bike thoroughly with a hose and brush. The work can only be carried out accurately on a clean bike.

Tighten 2 screws: Axles, brake callipers, discs and rear axle bearings in particular become loose and can crack, creak or rattle.

3 Provoke noise: Is it more of a cracking or rattling noise? Can the noise be reproduced, for example by loading the saddle, compressing the suspension, braking or pedalling in the saddle?

4 When′s rattlescan also be caused by the motor - there is nothing the do-it-yourselfer can do about it (see interview). Nevertheless, it is still worth checking the battery compartment.

4 Cracking or creaking tend to indicate noise sources other than the motor or battery. Then first check classic problem areas such as the saddle, rear wheel bearings and headset. Here we show you how to proceed in detail:

If it's the battery

If it's because of the trains

Motor noise on an E-MTB? Interview with Merida product manager Benjamin Diener

The E-MTB rattles - if it's the battery:

Loud rattling on the trail and you suspect the battery compartment? Lift the front wheel using the handlebars and bump it hard on the ground - this often helps to confirm the suspicion.

1. turn sensitive fittings, such as the display and control unit, on the handlebars so that you can turn the bike upside down - in most cases, this makes it easier to work on the battery compartment. Place a cloth under the handlebars to protect them from scratches.

2 Now check whether the battery cover has any play when closed. If the cover has a lot of play and can perhaps even be lifted slightly, this may be the cause. Next, check the battery. If it can be moved without much effort, the screws in the battery holder may have come loose. Carefully tighten the screws if necessary.

If this is not possible or does not help, the battery mount must be adjusted by a specialist workshop. Incidentally, the battery mount usually comes from the bike manufacturer itself. Ideally, you should therefore visit a workshop that sells bikes from your manufacturer for adjustment.

Also check whether the battery shows signs of grinding or damage. This would be an indication that the battery is in contact with the battery cover, the frame or the cables or that there is play in the holder.

3. all screws are tight, everything is adjusted as well as possible, but it still rattles? Then start by making slight modifications to the battery cover. First check whether slight play can be eliminated by applying some protective film - as in our case on the nose of the battery cover.

4 If the battery and battery cover hit each other, a wide strip of impact protection on the inside of the battery cover can help. Thin, self-adhesive door protection mats or bitumen mats from DIY stores work well. Do not apply the film to the battery itself!

5 Only as a last resort can you also try to cover the inside of the battery clip with the impact protection film.

Eliminating e-bike noises: if it's the cables

Also check whether loose or poorly laid cables under the battery holder are causing the rattling. Clear guides that hold the cables firmly in place are ideal.

1. if this is not the case, carefully try to pull the cables taut towards the front of the frame. Then tie several loose cables together with a cable tie. Bend the cable tie at the front to make it easier to thread it under the cables. Do not overtighten.

2. individual, loose cables can be easily stabilised with foam sleeves that are pushed over the outer sleeve. Cut the foam sleeve open lengthways, put it over the cable and close it with adhesive tape. This avoids having to remove the cables.

Motor noise on an E-MTB? Interview with Benjamin Diener, Product Manager Merida

EMTB: Is it possible to influence the motor noise at all, for example through the frame construction?

Benjamin Diener: The frame and motor work together. It is important that the frame does not amplify the engine noise like a guitar case. However, this is difficult to simulate in the design - especially at the current pace of development. Issues such as safety, geometry and chassis clearly have priority.

Was there ever a case where the frame amplified the engine noise unfavourably?

A few years ago, we had a step-through bike that was vulnerable because of the bulky down tube. But now we have the problem under control.

What role does the material play? Does carbon tend to be louder than aluminium?

Rather the opposite is the case. Carbon tends to dampen engine noise, while aluminium transmits it more directly. However, generalised statements are difficult because shape and wall thickness also play a role.

There is also a series variation in engines. Does this play a role in the noise?

Absolutely. We have already had engines that howled conspicuously and which we then sent back. But that is the exception rather than the rule, even with large quantities.

In addition to the uphill noise, downhill rattling can also be annoying. What role does the frame construction play here?

Especially when it comes to routing the cables in the frame, there is a lot that can be done well or badly. However, the loudest rattling of the current generation of drive units is usually the motor itself. Even we are relatively powerless against that.

>> You can find out how to eliminate creaking and creaking on the bike here <<