I have an Emerson Accupower model 20. It is an european model so the battery is 24v. The charging circuit is rather clever, consisting of an extra winding in the transistor fed with an optoisolator and triac. The switching mosfet's internal diodes then work as rectifiers. However, it's not charging properly. If I replace the batteries with a capacitor, the voltage stabilizes around 19 volts, and the 24v battery gets completely depleted then.
Should I really bother with repairing it at all or just hook up a separate small float charger?