Apad / Irobot battery upgrade

[johngyver]

A question for you seasoned vets here... I recently purchased an Apad/iRobot pad off ebay... here is a link;

New 7" Google Android 2.1 Tablet PC Netbook UMPC MID - eBay (item 290476714174 end time Nov-16-10 07:01:54 PST)

The battery life is rather weak, 1500 mAh. I opened up the apad, which was easy... 4 screws on the back, and saw the internals. There are two 3.7v battery packs wired in series to 7.4v. I am an electronics tech (audio) so I found these iphone batteries on ebay that I will use to upgrade the existing battery packs.

Battery Replacement 3.7v 1600mAh for iPhone 3G 8GB 16GB - eBay (item 250629070553 end time Nov-03-10 23:30:52 PDT)

I went with this specific model because of capacity (1600 mAh each) and the fact they have an external connection tab that I can solder leads onto. I am going to try to fit 4 of these in the apad for 6400mAh of combined power, wire 2 of them in series for 7.4v (twice) and then combine them in parallel.

I have two weeks before the batteries come in from China... in the meantime I want to bounce the idea off you guys for some feedback. From the looks of it there is room in the apad for the batteries... I was thinking about double stacking the iphone batteries to make two banks and set them in the same space as the two existing batteries. My only concern is heat from the batteries... if any.

Thanks for your input guys!

John Gyver

 

[gurgle]

There will be heat. and you will want to space/separate them with 2mm thermal insulation tape/foam. I helped a friend to the same thing. I did add a voltage stabilizer in the mix to make sure I did not overpower the circuit. The one thing I learned was how warm batteries can still get. If I were doing it again I would space/link the batteries rather than stack/link them.

If you know how to solder and simple voltage regulation, it is not a difficult task. I ended up using a couple of Lenmar batteries I had access. I wish the voltage input was located in a better location. Otherwise, I would add a Battery extender and velcro the battery back to the lower back.

 

[xenoyosh]

Hi! I just want to ask what is the status so far of this project?

I want to be able to do this for myself as well. I wonder if you could post a how to video or at least some how to pics and instructions. Thank you so much! I really appreciate it!