When I was in the market several years back for a portable 40 amp charger the Stanley BC4009 40 Amp Automatic Battery Charger was just coming out. Walmart stopped selling the B&D 40 amp charger so I called Stanley and talked to there engineering dept. To summarize what I learned is that Stanley and B&D were the same company now and the newer Stanley was basically the same as the older B&D model with better electronics. They still used the same noisy fan from the older B&D/Vector chargers. I was all set to buy the Stanley based on my conversation with their engineer when I found a B&D 40 amp charger at Big Lots for $50, they were about $100 before they were discontinued. For a battery system of 2 6v golf cart batteries the 40 amp charger works great. They have an equalizing function and a desulfate function. If you can't find the B&D 40 amp charger I would go with the Stanley.