What must a forklift charger support before it can charge a lithium battery safely?

Direct answer: Only if the charger matches the battery’s BMS limits. It must deliver the right voltage with a constant-current/constant-voltage profile, stay inside the pack’s current and temperature limits, fit the connector and, where the pack requires it, communicate with the BMS. Get that confirmed in writing for your exact charger model.

A charger is part of the battery system. Redway’s 51.2V forklift pages list an operating voltage range of 40V to 58.4V, and the 48V 280Ah table gives the charger as 0.5C @ CC/CV. The 48V 300Ah table says CC/CV without a rate. CC/CV means constant current first, then constant voltage as the pack nears full. Since 58.4V is the top of the stated window, a charger that pushes higher, or that runs a lead-acid equalisation stage, is not appropriate.

Current limits come next. The 48V 280Ah table gives a maximum continuous charge current of 150A (10–45 ℃); the 48V 420Ah and 550Ah pages give 200A (10–45 ℃); the 24V 230Ah page gives 150A; the 24V 50Ah and 24V 150Ah pages give 40A. Charge temperature is 0–55 ℃ on these pages. A charger rated above the figure needs an adjustable limit set by someone who has read the pack’s data. A charger rated below it simply charges more slowly.

Communication is what the web pages do not settle. The packs list RS485 / CAN bus / 4G and a Youdan BMS, but the product pages publish no CAN or RS485 protocol, no charger handshake and no list of approved chargers. Whether your charger must talk to the BMS, and over which protocol, is a question for Redway engineering. Do not assume it, and do not call a charger brand “compatible” without written confirmation.

Check the physical side too: the connector type (Rema on these pages), cable gauge for the charge current, and that the charger’s voltage class matches the pack (24V, 36V, 48V or 80V). Put charger replacement in the business case from the start, and ask Redway whether a matched charger is offered with the pack and at what price.

Before the first charge, write down the charger model, profile and current limit, and have the BMS data visible. The larger pages list SoC, SoH and a Forklift Cloud Monitoring System. IEC 62619, which these pages list, covers safety requirements for industrial lithium batteries, and its safety assumptions depend on charging within the maker’s stated limits.