V600 Battery Options Question

What are some of my options for installing a larger mAh battery in the
V600? I ordered the Motorola Slim Hi-Cap Li-Ion Battery (800mAh) - SNN5683
based on the Web picture and it's too big for the case. The battery I
received is not the one in the picture.

I have looked on the Web and believe there are larger mAh batteries and an
oversized cover available. Are there sources for the oversized battery
covers? Is this approach practical?

Comments and suggestions welcome.

Thanks
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TJ