CTek D250S

Dual-battery System
 

I have been meaning to install a dual-battery system in the old Hilux for some time, and so welcomed the opportunity to test a CTek D250S and have the installation done by Gareth Wyeth of Opposite Lock Wellington – one of the best in the business.

These are not cheap DCto-DC systems, but they are a clever solution for managing off-grid power resources, and they largely cut out the problem of human error. They combine the function of a smart battery charger, a battery isolator, and a solar/wind voltage controller.

For some background, I had a briefing on the unit’s capabilities from CTek’s Western Cape Area manager Melt de Kock, who has a wealth of experience. He explained that the D250S monitors the charge state of the vehicle’s cranking battery, and when the alternator raises voltage beyond 13.1 V, it will start charging the service battery or batteries with a maximum charge voltage of 14.4 V (and 20 Amps). If the charge state drops below 12.8 V on the cranking battery, the smart charger stops sending charge to the auxiliary battery, to ensure that sufficient power is retained for starting purposes.

You can also permanently add charge (maximum input 250 Watts) from a solar panel or a wind generator, or just when you stop driving for some time and need the extra power. Melt has a panel mounted on the roof of his vehicle which takes advantage of the D250S MPPT (Maximum Power Point Tracker) function, and automatically regulates inputs from the most appropriate power source. Other overlanders might opt to plug in their panels or wind generators only when needed; and, in this case, the automatic regulation function of the unit literally means plug in and forget. Another useful feature is the integrated temperature sensor – on the end of a wire which is placed next to the battery – which determines the correct rate of charge for the prevailing temperature. That is, more in cold weather.