My Lister Petter generator came with a "no name" alternator that failed within a few hours of operation. I notified the selling dealer and they sent me a replacement, and didn't want the old one returned. I tried to have the local alternator rebuilder fix it for a spare, but he couldn't figure out who made it, and couldn't source a replacement internal regulator. I started looking on eBay and eventually found an internal regulator for $7, so I bought two. Installed one into the first alternator and reinstalled the alternator on the engine. It didn't last very long, and I also realized that the replacement alternator was no longer working. I then put a 10 gauge wire onto the alternator and connected it to the battery, just like it was wired at the factory, thinking that the light gauge wire they had installed was the problem. Then I put the sole remaining regulator into one of the alternators and when I checked it, it was working. A few days later, after a power outage, I checked the alternator to see if it was still working, only to find that the regulator was defective. I gave up on the alternator and I keep a NOCO battery maintainer on the battery. The battery stays fully charged and the engine always starts. I have given up on the "no name" alternators as not reliable. Being a diesel engine, it only needs the battery for starting, and for pulling the stop solenoid.