Hi folks.
Recently my sister’s boyfriend gave me his TE to repair screen noise problem. When I opened TE – I discovered that there are tons of free space, enough for second battery. When I told him that this is possible – he was very happy , since Te’s battery performance is not great.
So while performing the process, I took pictures, so if anybody wants to follow – it would be easier for him. Before putting second battery – I performed a small test, Recharged Te fully, than opened Pocket Tunes andhttp://www.1src.com/forums/editpost.php?do=editpost&p=775844# left it to play on max brightness, and screen on - all the time. From full charge in this condition TE played about 2.5 hours , than died, While I’m writing this – It is already in 4.5 hours , and battery is still 65% - not bad at all. I expect at least double time.
I also have to say, that the battery that I added – was NOT new. TE’s owner bought new battery for his Nokia phone, and gave me the old one to put inside the palm. So If the battery was new – the result would be even more terrific.
Let’s start. This is the battery that I put inside TE :

I’m not sure about it’s capacity – but I guess it is about 600-750mah. I also didn’t take it’s full dimensions, but I measured it’s thickness – it is exactly 4cm thick.
After removing top black plastic, with protection circuit inside it (we won’t need it) it looks like this:
Than I soldered 2 wires, and covered with isolated tape. It is very important to cover all conducive surfaces battery might have. –so it won’t short anything inside the TE.

After opening TE – (w/o any changes yet) it’s inner looks this way:
As you can see – the battery is _soldered_ directly into mother board. There are no plug like in other palms. But it doesn’t matter – since you WILL have to solder anyway, and If you don’t want/know – don’t even try to start the mod.
First thing first – I fixed the screen noise problem, since it was one of things He asked me to do.
I won’t tell about it because there is separate thread of removing screen noise here:
http://discussion.brighthand.com/pa...&threadid=64429
I went with an improved version and put a transparent sheet between digitizer and screen. You can see this transparent sheet prepared here:

Next thing I had to do – is to remove the Te’s battery, here’s why: The Te’s own battery is even thinner – it is about 3mm. , so I had to put it on the top side of the board, because otherwise , the Nokia battery wouldn’t fit there. All those chips and electronics rise about 1-1.5mm from board surface. When detaching the battery – don’t use any metallic object. I would also recommend unsoldering it completely from the board (as I did) because operating on the battery while it’s still connected - is not safe.

The hardest part is to remove some part from the cover, otherwise it won’t close. Here are the things I had to remove from the cover to gain extra space for second battery to fit:
When you open Te’s battery top – you will see small protection circuit.
So you need to solder second battery to the first one – in parallel, which means soldering in to the pins of the first battery, plus to plus, and minus to minus. Please double check the polarity, because if you make mistake – you can throw out both batteries. Before connecting 2 batteries in parallel – make sure they are at the same state (approximately). For example, if one is empty, and second is full – this is not good, but not deadly (as polarity swap). I discharged both batteries before connecting,

Make sure you cover everything with isolating tape:

Hardest thing to do – is to position both batteries on the board, The Nokia battery goes to the place of Te’s battery, and Te’s goes to remained free space. It is exactly long to sit between SD slot (which is very tall) and Usb jack (which is tall too). Make sure you don’t cover the reset hole. First time I closed the cover – I covered the reset hole – so I had to open and redo by moving it slightly towards SD slot.
There is also a screw hole that can’t be covered, See large picture here:
http://junglemike.nm.ru/te_battery_large.jpg
I must say that I DID have trouble closing TE back and it didn’t close up smoothly. It got a little “blown up”, but almost unnoticeable, see here:

The major problem with this specific battery – is because it is too wide (and not too high) – but this is the battery I had to use. If you want to buy some cell phone battery specifically for this purpose – better choose one with has less width, otherwise you will RELLY have hard time to close it back, I had to remove some additional parts of the back cover (other than that are shown on pic) to make it close. I say on some other Russian forum somebody made a similar mod, and he used other cell phone battery (don’t know exactly which) – it was much smaller than this one, and maybe even polymer (while this Nokia batt is _not_ polimer and thus larger ).
Such modded TE requires more time to charge (about 50-100% more) which is about 5-5.5 hours. And for some reason indicator stays on 100% very long time (more than 80 first minutes of testing with screen ON – it was constantly on 100%). Also , practically, if you , say, double the battery capacity (say, instead of 1000mah – you put 2000mah ) - work time will be increased MORE than by 100% - I don’t want to be too technical, I will only say that this is has to do with battery internal resistance. This is especially noticeable on high battery-load applications (games movies,,,)