Hopefully will work few winters, do job exactly how charger need to do. Dead battery becomes alive and that’s all matter on -35c . Work great with single or multi battery vehicle (semi) Manual charger is what all of us need. Definitely worth to buy. One thing missing, switch where battery can be charged longer then 135min. When you charge 4 batteries with 1000amp each with only 10 amp/hour you need longer period then 2 hours so that’s need to be add on charger.