Safety · Great Britain

Batteries, chargers, and why 'it fits' is not enough

Voltage and a connector are not a compatibility test. The safe question is whether this exact pack and this exact charger are the combination the system names.

Author: ConvoKits editorial
Reviewer: Technical review
Published: 1 Oct 2026
Reviewed / next: 1 Oct 2026 · 1 Apr 2027

London Fire Brigade warns that poorly installed conversions and incompatible components can increase fire risk, and recommends the manufacturer-recommended charger and professional conversion support. UK statutory guidance on lithium-ion battery safety for e-bikes also covers conversion-kit batteries, protective systems, and the information needed to judge compatibility, including which chargers are compatible.

What does not count as a match

Similar voltage is not an approval.
A connector that plugs in is not an approval.
The word universal is not an approval.
Another owner saying it worked is not an approval.
An adapter being for sale is not an approval.

If the offer does not name a battery and a charger together, electrical assessment stops and asks for a qualified review. ConvoKits will not invent the missing pair.

If a pack is swollen, hot, damaged, hissing, or smells sharp or sweet, stop using it. Do not open it, do not keep charging it, and follow fire-service advice. This site does not give repair steps for damaged cells.

Shops are named on the configuration. Specification research is not labelled as a hands-on test.