I bought a Wen Cordless Sander/polisher and spare battery recently. I thought it might be a good sealant/liquid wax applicator. Sometimes it is nice to have a cordless tool due to the hassle of tight spots, plus hassling with cords isnt fun. In addition, there is portability, it seemed a versatile choice. I charged one battery, no problem. I put the other in the charger and came back about 4 hours later and the battery was really hot. Uncomfortable to hold hot ! It didnt take a charge.(so far it seems undamaged) I looked at everything and when I came to the charger, I saw a prong out of place... I still dont know the mechanics of it, but I bent it back into place. Ok that problem went away, but the contact for the power adapter was also intermittent, requiring careful positioning of the cord. Another disassembly, prong bending.
The polisher works fine, but the charger is the cheapest POS I have ever encountered. The ability to work without a cord for about an hour per battery is very cool, I could actually apply sealant/liquid wax to 3 cars with one battery. It is suprisingly efficient, but is not a tool for actual polishing, except for maybe a chemical based product like
AIO, and only then when the requirement is for very light cleaning.
Wen does not do itself a favor selling such a Cheap, ill designed charger.
This sander/polisher has its limits, however , within its performance range there is a good deal of utility, provided that the limitations are fully understood before hand. The charger is the only real problem with the product.
Wen Charger 
Linear Mode
