These batteries are aftermarket, by Digicom, for Sony Camcorders. There are two in question:

#1) Digicom Replacement Battery For Sony Same As FM70
* Rechargeable Lithium-Ion battery pack for DCR-TRV8 and DCR-TRV10
* Built-in microprocessor accurately calculates remaining battery life in minutes
* 7.2V, 17.0Wh with no Memory Effect
* Up to 5 hours of continuous recording time

#2) Digicom FM50 Battery for Sony Digital Cameras
* Rechargeable Lithium-Ion battery pack for DCR-TRV8 and DCR-TRV10, DSC-S30, DSC-S50, DSC-S70
* Built-in microprocessor accurately calculates remaining battery life in minutes
* 7.2V, 8.5 Wh with no Memory Effect
* Up to 3 hours of recording time

Links are:
http://www.tigerdirect.ca/applications/SearchTools/item-details.asp?EdpNo=469526&Sku=D135-1114&CatId=131
http://www.tigerdirect.ca/applications/SearchTools/item-details.asp?EdpNo=469527&Sku=D135-1112&CatId=131

It doesn't list the PDX10, nor a bunch of other cameras, so I thought I'd ask here. Perhaps the specs for the batteries don't match/aren't good for the PDX10?

Maybe I should ask, which batteries work with the PDX10.

The FM50 and the FM70?

There are always a bunch of them on ebay.....

Ronald, I know they cost more but I would personally stick with the real Sony Infolithium batteries. The model numbers you mention don't sound familiar. I'd suggest you consider the Sony NP-QM91 which is the largest you can put on a PDX-10. Unfortunately it doesn't have the stamina of a NPF-960 on the PD-150 (which can last 8 hours), but I've gotten 4 hours with the QM91 on my PDX-10.

I'd be very careful about 3rd party batteries on the Sony cameras, you can read about lots of third party battery problems on the PD-150, and recently someone discovered that the PD-170 refuses to work at all with 3rd party batteries that were fine in the PD-170. To me it just isn't worth screwing around to save some relatively modest bucks.

The NP-QM91 lists for about $110 at B&H: http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=275105&is=REG