Where to buy dp2m extra batteries?

Can I double check please - is the Ricoh DB-65 for certain the same as the Sigma DB 41 battery for the DP1M and SP2M?

I'm in the UK, just taking delivery of a DP2M and there only seem to one retailer (Clifton Cameras) of the BP41 batteries in the whole UK, and they are at £49 each (against £41.26 recommended retail on the Sigma UK website!). That works out at £98 for a spare set of the two batteries included originally.

That's 25% more than a spare Leica M battery!!!

I've just found a UK source of reasonably priced Ricoh DB-65 batteries (whilst stocks last) so am double checking these are identical.

Thanks

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David