[Closed] Supplier for Li-Ion batteries for multi-PDA support contract?

Does anyone here work with volumes of PDAs or mobile handhelds - in the hundreds?

I run a support department where one of our contracts is to support 400 PDA field users in London using the obsolete T-Mobile MDA III and over the last 18mths the performance, from new, of batteries received from the factory has deteriorated.

Does anyone have any contacts or suppliers of Li-Ion batteries for batch orders? I'm currently dealing with Cameron Sino in Hong Kong via a UK distributor and I'm really struggling to get batteries that perform properly.

I recently paid 150% per unit for a 100 new batteries with claimed 16% increased mAh rating, that have turned out to perform exactly the same as the previous batch. The supplier has offered to refund, but cost isn't the issue, I need the performance. My users PDAs are running out of battery before the end of their shift. This is the major bugbear.

Any pointers gratefully received.

John Moore