Camcorder DC adaptor cable

[timsabre]

This is a bit of a long shot but there are so many knowledgeable people here!

 

Last week I bought a Panasonic HMC151 camcorder from ebay, but the seller did not have the DC adaptor cable which is one of those "dummy battery" types linking to a standard DC jack on the charger. The cable does not seem to be available as a spare part any more (part number k2gj2dc00022 if anyone knows better). It's got several batteries which work fine, but it needs a software update to work with Class 10 SD cards, and it won't do the software update unless it is connected to the DC power adaptor.

 

The battery has 4 terminals, + - D T. From googling I believe that T is a thermistor in the battery connected to battery -ve. D is a data connection which is used to monitor the battery charge level within the battery. Or possibly tell the camcorder what type of battery is attached.

 

I thought I could have a go making one by buying a cheap OEM battery, removing the guts and connecting a power cable to the + and - terminals. However, the camera does not power up. So something is obviously required on the D or T terminals. If it's looking for a data handshake on the D terminal then I am probably stuffed but some people making DC adaptors for Lumix cameras have found that a 10K resistor on the T terminal will fool those cameras into thinking that they have a genuine panasonic battery attached. I'm going to try some things with the T terminal later today... but if anyone knows any more I would be happy to hear about it...

[DrV]

I don't know anything about the data line but the 10k sounds right. I have been working with various LiIon charger chips recently and they all specify a 10k pull down on the thermistor line if you're not actually using a thermistor.

[timsabre]

Hmm so with a 10K resistor between T and - it powers up, but then shows "This battery cannot be used" and shuts down again.

Tried connecting T to ground directly, does not power up.

 

 

Doh... problem solved. The DC jack at the charger end of the cable was not making contact properly so there was no power on the cable.... in fact it works as I originally had it, just + and - connected. Now to attempt the firmware upgrade.