I changed the original battery to 453030 (4.5mm, 30mm, 30mm). It fits nicely, no glue needed since it seems to be tight enough without the glue (or is just left the old glue as it was in the V800 base plate). The battery replacement requires soldering and I have two comments to the above procedure: there is no need to disconnect the wires from the base plate if you change the battery only (Step 7 above, dont disconnect the wires). The wires are connected to the mother board and those wires (red and black) need to be disconnected first. And the new battery requires the same soldering points, one for positive (red) and one for negative (black wire).
The cost of the battery was about 11 euros (from a Chinese web store, delivery (6e) included), about 12 USD.
