OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Trimmers and Brushcutters Two Stroke Trimmers & Brushcutters Anyone here own an auto-start Tanaka?

Someone was discarding a Tanaka AST-5000 edger because the charger had disappeared and the battery was dead. From what I understand, each of these items costs a fortune. But I can make the battery pack and there's probably a standard charger that would do the job.

Does anyone happen to know what voltage output the Tanaka charger is?

justallan,

The part number is 663-37655-90 and retail price is $70.50. The voltage is 8.94 volts using 240volt.

You should be able to get a charger at [Censored] smith or Tandy that will do the job but you will also need to buy the correct connection so that you can plug it in to the battery.

Thanks Bruce - I spent hours last night looking for that info. How did you find it? Wherever it was, could you please look again and tell me exactly what it says all the outputs are? (AC out or DC out? Volts? Watts?) The reason I ask is, I've now pulled the battery pack and found some circuitry in there too. It's just a diode and a black box that looks like either some kind of relay; an AC to DC converter; or overheat cutoff.

So it's possible the charger is just a simple "240 in, 9V AC out" - and that black box & diode converts the "charger" output to something else.

The battery pack is just four "sub C" size cells. That makes 1.2V x 4 = 4.8V. If the cells are charged directly from the charger (without going through other electronics) the charger should be *about* 6V (to allow for a little voltage drop under load). But that extra electronics makes it a pain in neck to work out what charger is needed (without buying an oscilloscope!).

Sounds like the black box may be a 5V voltage regulator and current-limiter. There is a chance it still works, and only the cells are dead. You might try disconnecting the cells from the black box and providing a standard 9 volt input to it, while measuring its output voltage. This is only a good idea if you are used to dealing with electronics, but you sound as if you are. The upstream diode is probably there in case some amateur reverse-polarises the input, which would fry the regulator if the diode wasn't there.

Yeah thanks... I'll have to get the part number off the black box and see what comes up in a search engine. (Try and work out what it is exactly.) Lots of manufacturers spend all the R&D money everywhere else, then make pathetic chargers. I don't know if Tanaka falls in that category, but if so, the charger could simply be a plain 240V AC to ~9V AC (not DC) plugpack, and the diode could be the cheap & nasty half-wave rectifier to charge the cells.

Of course, that would mean the charger pumps into the cell pack 24/7 until you switch it off manually. Nasty stuff, but it wouldn't surprise me.