A: Thank you for your question. The DC18SE will charge Makita 18V Star protocetid battery.
A: Thank you for you for your question. We do not offer 12v automotive charger.
A: Thank you for your question. No, the DC18SE 18V LXT® Lithium-Ion Optimum Automotive Charger is not capable of charging 12 Volt batteries. Please see the DC18RE 18V LXT® / 12V max CXT® Lithium‑Ion Rapid Optimum Charger.
A: So, the straightforward answer to my question is NO, the charger won't turn itself off before it runs your truck battery down. Trying to get a useful answer, I researched batteries- typical battery capacity for a car might be 35 amp-hours, typical for a truck might be 50AH. If this charger is 50% efficient, then recharging a 5AH Makita battery would use 10AH, a little under 1/3 of the capacity of a car battery, 1/5 of a truck battery. With a reasonably warm engine, that would probably leave a enough Reserve Capacity (RC) to start the engine. These are VERY rough but fairly conservative calculations, so my guess is you'll generally be OK recharging one 5.0AH Makita battery, but more than that, you should probably have the engine idling to recharge the vehicle battery. Recharging a couple of smaller Makita batteries (say, 3.0AH) would probably be OK too.
A: I believe so. Here's why: when I put a 5.0ah battery on the charger, and the vehicle is running, charges just fine. And most of the time without the vehicle running it charges just fine. BUT sometimes, when I'm opening and closing doors, lights are on all day and the vehicle battery is too low to start, I look at the charger and it is flashing red and green lights indicating bad battery. It's not really bad, there just is not enough juice to charge the battery. I've noticed after using this charger for over a year, it does this occasionally when the vehicle is not running
A: Thank you for your question. The charger will continue charging batteries for as long as there is power to draw from, but the charger will shut off after the battery is fully charged.