Helpful, thank you Roger. What you say applies to the R730i too. I found that I had to loosen the 3 screws under the shaver head so I could lift it up a bit to be able to get the beard trimmer out. The tricky part was finding the exact spot to insert a screwdriver to remove the cover plate on the bottom. On the R730i, hold the shaver looking at the charging connector so the writing is the correct way up and the base looks like a pyramid with a domed top. Insert your screwdriver just to the left of top centre, near the edge of the silver trim that runs up the side of the case. If it were a clock face, it would be between 11 and 12. It isn't the silver trim you need to pry off but insert in the tiny gap in the blue plastic just under the trim.
They are a pig to change, but if you want to do it and you have the facilities and the patience, here's what you need to know:
You require 2 off AA cells with solder tags. The originals are 1600mAh and so you should obtain replacements of at least this capacity. I obtained 2000 mAh batteries.
There are four hidden screws which you need to access. At the base (where the charger plugs in) you need to remove the cover. Insert a thin screwdriver blade in the side furthest away from the connector (on the side of the base) just to one side of the centre. With luck the cover will pop off with no damage, but if you do damage it it really doesn't matter too much if it can't be refitted later. Beneath this are the first two hidden screws. Remove them. Then remove the trimmer - first open the shaver head and remove the cutter assembly by pulling it up from the pivot. Press the trimmer slide inner arms towards each other and disengage the pivots.The trimmer itself can then be removed by carefully unclipping it. Then squeeze together the arms from which you have just disconnected the trimmer and the whole grey/brown assembly will come out revealing two more screws, which should be removed.
The back will then come off revealing the batteries. You'll need a sharp craft knife to cut through the blob of silicone attached to both batteries, taking care not to damage the temperature sensor embedded in it and soldered into the circuit board underneath. Cut through the battery solder tags (the cut ends can be more easily removed when the batteries are out) and remove the batteries. The ends nearest the shaver base are joined together by a short wire which is likely to also be embedded in the silicone - you'll now be able to get this out for reuse. The batteries have plastic tape to provide insulation on the terminals but this can be easily removed at this stage.
Solder in the new batteries - the red wire from the circuit board to positive on one battery, the white wire to negative on the other one. Link together the positive and negative 'other ends' nearest to the base - the idea is to have two 1.2V cells in series to give 2.4V. Insulate the exposed battery terminals with insulating tape.
Replace the back after checking that the motor runs indicating you have no problems. Reassembly is more or less the reverse of disassembly, making sure that the back cover gasket is properly in place.
Note you do not need to get access to the top of the shaver - other than removing the cutter block. You should now be in business!
Final note on charging: initially charge until the case gets noticeably warm - probably around half an hour. Then use the shaver normally until it cuts out - probably long after '0' is shown in the display. Then recharge until '60' shows in the display. Stop charging at that point. Don't leave the shaver plugged in - overcharging is the problem and it will shorten battery life if you charge beyond the point where '60' shows. Although if you have used larger capacity cells than original you'll get more than an hour on a full charge, it's kinder to stop a bit short. It really does make a big difference.
Answers & Comments
Helpful, thank you Roger. What you say applies to the R730i too. I found that I had to loosen the 3 screws under the shaver head so I could lift it up a bit to be able to get the beard trimmer out.
The tricky part was finding the exact spot to insert a screwdriver to remove the cover plate on the bottom. On the R730i, hold the shaver looking at the charging connector so the writing is the correct way up and the base looks like a pyramid with a domed top. Insert your screwdriver just to the left of top centre, near the edge of the silver trim that runs up the side of the case. If it were a clock face, it would be between 11 and 12. It isn't the silver trim you need to pry off but insert in the tiny gap in the blue plastic just under the trim.
They are a pig to change, but if you want to do it and you have the facilities and the patience, here's what you need to know:
You require 2 off AA cells with solder tags. The originals are 1600mAh and so you should obtain replacements of at least this capacity. I obtained 2000 mAh batteries.
There are four hidden screws which you need to access. At the base (where the charger plugs in) you need to remove the cover. Insert a thin screwdriver blade in the side furthest away from the connector (on the side of the base) just to one side of the centre. With luck the cover will pop off with no damage, but if you do damage it it really doesn't matter too much if it can't be refitted later. Beneath this are the first two hidden screws. Remove them. Then remove the trimmer - first open the shaver head and remove the cutter assembly by pulling it up from the pivot. Press the trimmer slide inner arms towards each other and disengage the pivots.The trimmer itself can then be removed by carefully unclipping it. Then squeeze together the arms from which you have just disconnected the trimmer and the whole grey/brown assembly will come out revealing two more screws, which should be removed.
The back will then come off revealing the batteries. You'll need a sharp craft knife to cut through the blob of silicone attached to both batteries, taking care not to damage the temperature sensor embedded in it and soldered into the circuit board underneath. Cut through the battery solder tags (the cut ends can be more easily removed when the batteries are out) and remove the batteries. The ends nearest the shaver base are joined together by a short wire which is likely to also be embedded in the silicone - you'll now be able to get this out for reuse. The batteries have plastic tape to provide insulation on the terminals but this can be easily removed at this stage.
Solder in the new batteries - the red wire from the circuit board to positive on one battery, the white wire to negative on the other one. Link together the positive and negative 'other ends' nearest to the base - the idea is to have two 1.2V cells in series to give 2.4V. Insulate the exposed battery terminals with insulating tape.
Replace the back after checking that the motor runs indicating you have no problems. Reassembly is more or less the reverse of disassembly, making sure that the back cover gasket is properly in place.
Note you do not need to get access to the top of the shaver - other than removing the cutter block. You should now be in business!
Final note on charging: initially charge until the case gets noticeably warm - probably around half an hour. Then use the shaver normally until it cuts out - probably long after '0' is shown in the display. Then recharge until '60' shows in the display. Stop charging at that point. Don't leave the shaver plugged in - overcharging is the problem and it will shorten battery life if you charge beyond the point where '60' shows. Although if you have used larger capacity cells than original you'll get more than an hour on a full charge, it's kinder to stop a bit short. It really does make a big difference.
Roger.