Benson, would you mind also showing a closeup of the solder points without the battery in? I am interested in doing the same mod, seeing how great yours turned out =D

Hi Benson,

I know this is an old post, but would you mind commenting on how has it been working all this time?
I wonder if I can do this but with the normal cover and battery, I don't want to make it any thicker.
Also, if you could share more pictures, with the phone closed, charging, etc, that would be nice.

I ordered a touchstone kit and have the Mugen cover and one of the double Scud packs. I am hoping to make mine with metal contacts rather than a wire between the battery cover and the phone.
I am not finding the Mugen covers on eBay anymore though and am not sure where to find them for my wife's N900.

I am having a problem finding a Li-Po charger circuit like Benson uses in the diagrams upthread . Anyone have any good ideas?
Would some USB to 3.7v battery charger be good?
What voltage comes out of the Palm Touchstone module, I assume near 5v? How much amperage will it supply?
User Benson has gone the way of many TMO users since 2011 so I can't ask him.

So I have the Mugen back, a Palm Touchstone back and the touchstone base. I still need to get the battery charge regulator so I can solder down to the battery contacts. In my testing I think I will be able to use this with a double Scud battery pack without cutting the battery case.

I have not yet measured any power at the gold contact points on the case but I also have been using an underpowered Nokia 5.7v 800mA charger rather than the Palm wall wart but I do hear pulsed buzzing from the base. I think the Palm USB charger gives 1000mA and something between 5.7v and 6v making compatibility with non palm chargers sketchy. It will not take standard USB power. I get no response at all with my N900 charger plugged into the touchstone base. From several forums it seams that the base does require shorted data cables before it will accept power. I am considering shorting pins 2 and 3 inside the base on the PCB but enough voltage is still a problem.


Some other notes is that the polarity is +Positive for the gold contact near the PALM name and X-ed out trash can on the sticker that holds down the coil and -Negative for the gold contact on the cover nearest the impression of the coil on that sticker.


I do not recommend disassembly of the base as there are some spidery wires to a small coil that are easily broken, though carefully cutting the USB port hole on the base open makes using alternate cables easier.

http://www.ifixit.com/Teardown/Palm-...Teardown/810/1

http://www.pocketables.com/2010/06/h...s-charger.html

http://forums.webosnation.com/webos-...tone-dock.html

Bill of goods for converting 2xN900s:
-2x mugen battery covers, search ebay for extended battery cover N900 not listed as mugen
-2x 450mA USB charger for e-cigarette battery (thanks dr frost dk) to rip battery manager board from
-4x blue scud battery, to make two 3000mA/h double battery packs
-2x Palm Pre cylinder wall wart AC to USB, this is what the base needs and they are now pretty reasonable on ebay/amazon
-2x Palm Touchstone bases, they pretty much require the real palm charger above, the N900 charger is a no go so might as well buy the real deal than save a $2-3 on an incompatible power supply
-2x Palm Pre Touchstone backs, to harvest the coil and circuit board
-Hobby brass, will snip to the right shape to make contacts between door and N900/harvested charge regulator soldered to N900 battery +- poles.

I have one Mugen N900 door with the Palm/Touchstone coil installed, the sticky holding the coil is weak, I might try cleaning the next one with alcohol before sticking the coil down. The magnet is just strong enough to hold the phone down to the charge pedestal. Will see what works when the other touchstone door, batteries, regulators, and Palm wall chargers arrive.

It is a good idea to use some Scotch double sided sticky tape to pin down the coil and little metal buttons to the sticker that covers them and holds them to the phone battery cover. The clear inner sticky film that comes with the palm cover will probably be ruined in harvesting and you don't want to loose those little 5mm metal buttons which are needed for the magnets on the base to grab your phone and start charging, also your touchstone charger wont stick properly to your Mugen cover unless you do a quick clean off with alcohol and use the double stick tape to get everything attached.

Just wanted to post an after mod story.
The inductive charging works great especially on my wifes N900 with a broken USB.
The downside is that since I am wired direct to the base of the battery contacts I am bypassing the whole charging system; I often reboot the phone after undocking in the morning to get an accurate battery reading.
I run a double scud battery and I never have problem charging overnight and a few times got 80% from nearly flat after just a few hours.
One big upside to bypassing internal charging logic is I never get the dead battery makes phone unchangeable.
Anyone else using the touchstone system I am curious if the palm 12v jack actually works with the inductive touchstone puck for car charging?

Does anyone know if it is possible to play with charging scripts so that we could solder directly onto the system board rather than requiring a charging circuit to be crammed under the battery cover along with the inductive loop. Of course we would want to preserve USB host mode and charging.

One crude option is adding a shorting switch to the USB data pads under the battery but this is very inconvenient requiring shutdown, switching, and bootup before the USB port can be used.

The N900s I had modified with Touchstone have all broken or became corrupted with no option to reflash their USB ports being broken, no fault of the Touchstone mod.
I have decided to go with QI on my next try with our newer N900s since that is now the industry charging standard.
There are inexpensive universal charging adapters which have a flat cable which leaves the battery door and plugs in as a cover-plug for the microUSB port.
I am waiting for the delivery but while there seems to be progress towards enabling charging without shorting the data pins with modified battery scripts and the BME replacement the QI universal receiver and plug will work normally in charging status indication, protect the USB port from dust, and is easily removable when I want to use USB host mode, mass storage, or USB 3G network tethering for my laptop.
for example:
http://www.amazon.com/Universal-Wire...dp/B00I1D4DV0/