TimH Posted September 7, 2011 Report Share Posted September 7, 2011 I was going to modify the Dewalt DW9116 Charger to allow me to charge other vendors batteries. When I opened it up, I discovered it is not isolated by a transformer from the line. This makes it unsafe to add any externally accessible connector. **Do not even think of modifying it in this way, as there could be severe shock hazard if connections are brought outside** I took a few pictures and added some notes as others may find it interesting. (I am an Engineer) The charger seems to use a custom control IC, marked with what may be a B&D part number (starts with BD). For old batteries with no internal temperature sensor the charger uses a temperature sensor thermally coupled to one of power connector pins. As the battery heats up at end of charge (or if hot from use) the controller senses the conducted heat from battery via the connector pin which is welded directly to last cell in battery. For newer batteries, they have an internal Negative coefficient Thermistor, brought out on a third pin on the connector. This is a much better method as it is better coupled thermally to cells, but adds a small cost to each battery. Quote Link to comment Share on other sites More sharing options...
Madtec Posted September 8, 2011 Report Share Posted September 8, 2011 Very good observation The new 20v max chargers are totally different Quote Link to comment Share on other sites More sharing options...
tooljoe Posted September 9, 2011 Report Share Posted September 9, 2011 For newer batteries, they have an internal Negative coefficient Thermistor, brought out on a third pin on the connector. This is a much better method as it is better coupled thermally to cells, but adds a small cost to each battery. thanks, I was wondering why there is a 3rd pin in my battery packs. Quote Link to comment Share on other sites More sharing options...
medmike Posted December 10, 2011 Report Share Posted December 10, 2011 Oops...I just added to output lines for other charging to a DW9310 charger-soldered to neg and pos. Wires are insulated and contacts are also isolated-ill add pics. Let me know how dangerous this is or can wiring be modified to add transformer (maybe DC9310 has transformer?...too lazy to tear apart and snap pic just yet). Thanks Uploaded with ImageShack.us Uploaded with ImageShack.us Quote Link to comment Share on other sites More sharing options...
medmike Posted December 10, 2011 Report Share Posted December 10, 2011 Took a look inside the DW9310 charger...looks like transformer is in there. Here is pic. Uploaded with ImageShack.us Quote Link to comment Share on other sites More sharing options...
chrisa72 Posted October 19, 2013 Report Share Posted October 19, 2013 Hi Tim H. Having rebuilt a nicad battery pack and managed to cock it up good and properly, I have also managed to fry what appears to be a diode within the charger. It referenced as D26 to the RH side of the "Buck Regulator" it appears to be blue with some coloured bands on it. Can you tell me what it is please and its associated value. Kind regards Chris Quote Link to comment Share on other sites More sharing options...
TimH Posted December 1, 2013 Author Report Share Posted December 1, 2013 >>> D26 to the RH side of the "Buck Regulator" it appears to be blue with some coloured bands on it. Can you tell me what it is please and its associated value. <<< Chris, That is a resistor not a diode. It is R26 not D26. Search on web for resistor color code and you can figure out the resistor value, from the colored bands. It looks like at least a 1/4 w resistor. I don't have a large picture anymore and it is difficult to see the colors in the small picture I posted. The gold band at the end means 5% tolerance. It looks like it has 5 color band . If the colors are orange-black-green-brown-gold then it likely is a 3050 Ohm resistor 5% 1/4W T Quote Link to comment Share on other sites More sharing options...
skidmark Posted December 8, 2013 Report Share Posted December 8, 2013 Did anyone on this post ever figure out what the pinout is on the BD2003XR3 chip? Al Quote Link to comment Share on other sites More sharing options...
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