Deltran's high efficiency Battery Tenders have been designed to comply with legislation already in place in some states (California and Oregon), and likely to be in place nationwide by 2017, that requires battery chargers to operate at 90% efficiency or higher.
This Battery Tender Junior HE is a fully automatic two-stage charger, and is perfect for all lead-acid, sealed maintenance-free, and gel cell batteries. It has a slightly lower charging capacity (.75 amp versus 1.25 amp) than the larger model. The difference in maximum charging rate would be significant only in the time required to bring an exhausted battery up to full charge. Used over a long term to keep a battery topped up, the lower charging rate would make no difference in performance.
The Battery Tender Junior HE comes with one set of conventional battery connection clips plus a quick connect adapter (extras available separately), and is for 12-volt batteries only. It is spark proof, with a 12-foot output cord, and 5-year warranty.
Please Note: Battery Tenders for the North American market are designed to be powered by 120 VAC line power. It is important the line voltage be reasonably stable. Input voltage that rises and falls significantly will damage your Battery Tender. Typical, minor line voltage variations are not an issue. Powering a Battery Tender with a portable generator could be very bad for the Battery Tender as generator voltages can fluctuate greatly especially during start up and shut down. The same damaging voltage peaks and valleys can happen when trying to "step down" 240 VAC line voltage with a portable transformer. If you need a Battery Tender for 240 VAC line current, you should consider the 2-bank Battery Tender, which can be switched between 120 VAC and 240 VAC as needed.