Puch Kraftwerk 7G eBike Compatible Battery 25.2V 18Ah

Puch Kraftwerk 7G / 8G — 25.2V Li-ion Replacement Battery

This is a 25.2V 18000mAh (453.6Wh) lithium-ion battery for the Puch Kraftwerk 7G and Kraftwerk 8G electric eBikes. It replaces the factory pack that powers both pedal-assist and throttle modes. Fit the Kraftwerk 7G or 8G only — do not install on other Puch eBike models without confirming voltage and connector match first.

• Kraftwerk 7G and 8G platform: Both models share the same 25.2V nominal voltage rail and battery bay dimensions. The BMS handshake protocol, connector pinout, and charge cutoff voltage are identical across the two variants, which is why a single pack serves both.
• Bench tested on actual hardware: We ran this pack through charge-discharge cycles and monitored BMS behaviour under simulated motor-start surge current. The protection circuit responded correctly to over-current events and held stable voltage delivery across the discharge curve.
• First-ride charging after winter storage: After any extended period off the bike, charge this pack slowly using the standard Puch charger before the first ride. Cold Li-ion cells carry higher internal resistance — forcing a fast charge below 10°C causes lithium plating on the anode that permanently cuts cycle life, even if the battery reads as full.

Motor cutting out mid-hill on the Kraftwerk after fitting a new pack

Sustained climbing draws peak current from the battery for longer than flat-road riding. If the BMS detects current above its over-current threshold — typically triggered by a steep incline combined with a heavy rider load — it trips and cuts power to protect the cells. The motor goes silent, the display may flicker, and the bike freewheels. This is not a faulty battery. Stop pedalling, wait 10 seconds for the BMS to reset, then resume at a lower assist level to keep current draw below the trip point.

Charger LED stays green or won't begin charging after the eBike has been in storage

If cells discharge below roughly 2.5V per cell during storage, the charger's input circuit sees a pack voltage too low to enter normal CC/CV charging mode and refuses to start a charge cycle. Connect the charger and leave it plugged in for up to 30 minutes — most chargers run a low-current trickle pre-charge to bring the pack above the acceptance threshold before switching to full current. If the LED shifts to red or amber within that window, the recovery cycle has started. If nothing changes after 30 minutes, measure pack voltage at the output connector — a reading below 18V on a 25.2V pack indicates deep-discharge cell damage.