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CTEK Assist helps you with everyday questions for your 12v/24v or EV Chargers and includes product information, a product selector tool, troubleshooting, user manuals, compatible accessories and much more.
It draws on CTEK’s knowledge and documentation to point you in the right direction—fast.
CTEK Assist for CS ONE (Gen 1 & 2)
The CS ONE shows two steady red lights, what does that mean?
If the indication shows immediately when attempting a charge, check that the connection is not short circuited or that the battery voltage is not higher than 16V.
If the indication shows some time after charging has started, this means the charge is interupted as there might be something wrong with the battery. Disconnect all possible consumers and try again.
If the problem persists, CTEK recommend to get the battery tested - it may need replacing.