As a part of our Land Rover Defender build, we also needed to upgrade our Dual Battery System, requiring a modern system that could charge our second/leisure battery and also ensure that the starter battery is also protected and maintained, that would allow us to use either 12V lead acid batteries or lithium batteries and that could also provide battery and charge status information. Our partners CTEK are the leaders in battery charging technology and so this choice did not require much analysis, we decided to go with the CTEK, D250SE Charger, with SmartPass 120A Power management system and we also added the CTEK Digital Battery Monitor.

The D250SE is a fully automatic, 5 step charger that supplies up to 20A of power to any 12V lead-acid or ­lithium* service battery from 40–300Ah. It has ­selectable charge algorithms for AGM and lithium* batteries and can use power through its dual input from alternator and solar panel. When the service battery is fully charged, the D250SE will ­automatically redirect maintenance charge ­power to the starter battery. The D250SE can maintain a stable output up to 20A to vehicles fitted with smart ECU controlled ­alternators and also has a temperature sensor for ­optimised charging, regardless of weather conditions. *) 12V lithium batteries (LiFePO4, Li-Fe, Li-iron, LFP)

Smartpass 120S is a 120A Power Management Solution which distributes, controls and maximises the available energy from your alternator to power service batteries and consumers. SMARTPASS 120S handles all 12V batteries between 28-800Ah. The Smartpass 120Ss Battery Guard function ensures that critical equipment such as radio, emergency lights and navigation systems always have power and take priority when the voltage on the service battery is low, disconnecting non-critical consumers. The unit’s Battery Guard will protect your service battery from total discharge and built in over temperature protection reduces charge current before the battery temperature gets too high. SMARTPASS 120S is compatible with the D250SA and D250SE 20A on board chargers.

An optional add on the Ctek Digital Battery Monitor Display For 12v Volt Dual Dc Dc Solar Charger AGM Batteries This Digital Battery Monitor is the perfect companion for the CTEK D250S DC to DC Charger , the unit is compatible with any 12 volt system when installed as per the supplied wiring diagram.