Model: BLS-12/24B. The best way to use the BLS is to connect it and forget it. If you need to rejuvenate your batteries, connect the BLS and use the system as normal. Awarded a Patent in 2008, the BLS.
I hooked this device up to my weak batteries in my truck. The battreies were 2 1/2 years old. The truck would still start but would turn over slow. The batteries were not shorted out but just week. After using this device for a week as directed my batteries would not longer hold a charge. I had to buy two new batteries to replace the old ones. This thing is a waste of money.