Review on Schumacher DSR ProSeries Battery Charger with Engine Starter Boost and Maintainer - 330 Amp, 6V/12V/24V - Ideal for SUVs, Trucks, Large Engines and Automotive Shop/Dealer Use by Robert Viher

Schumacher customer service is great when they realize you actually know what you are talking about. My devices' flash programming mode didn't work right away, but they took care of me. Overall this is a great charger, the desulfation mode works and brought back an AGM battery that was over 10 years old. Update: Flash memory programming mode works, but the output current is slow and unstable. For example, if you suddenly turn off the load, the voltage will increase significantly, if you add a load, it will drop and respond very slowly. I made a video and started an exchange hoping this unit is just defective. I will update my review when I have a spare unit to compare how they perform. If the replacement unit has the same voltage regulation problem it will be a big problem as the voltage jumped over 19 volts when connected to a good fully charged battery! During flash programming, you often turn on the ignition, fans, lights, and other loads. Imagine if he lowers the voltage during PCM initialization he can ruin it. I emailed Schumacher but didn't get a reply after a few days so I decided to post this review and take it out of the cycle. Update #2: A replacement device has arrived, which I checked immediately, of course there are also voltage drops, although not as bad as the first part. For now I will recommend avoiding the device and buying something else, it's a shame really. The device should respond faster to voltage changes. I worry that cars that monitor voltage while flashing, like BMWs, might knock you out of a flash because it takes so long to recover from a voltage drop. What I also don't like is that it doesn't have a power indicator when in flash mode you have no idea how many amps the unit is drawing. I expect more from the DSR series, especially given the cost of this device.