7.4 V Lithium-Ion Battery Pack for Video Camera need Circuits Diagram

[lazy-b]

I got this 7.4 Volts Lithium-Ion Battery Pack for Canon Video Camera, has a short Battery life, so I try to make my own Battery Pack using my existing Lithium-Ion Battery.

The Original Canon Battery Pack has 4 Terminal, its Positive, Negative, D and B terminal as indicated in the Battery.

I just use a 2 cell Lithium-Ion Battery connected in series and just connect it to the terminal of Positive and Negative, the Camera works perfectly, but the problem there is no battery life indicator appear on the LCD screen......its just work as if the video recorder is connected to POWER ADAPTOR.

I have no idea what is terminal D and B, my guess it use for Current sensor or temperature sensor, Upon openning the original Battery pack, I have found a very small circuits board with 2 pcs 8 pin SOIC IC's.

Do you have any Idea how to get the circuit diagram of this circuit board.

my other alternative is to make my own battery indicator attached on the Battery.

Ellion

[Acetronics]

Hi, Ellion

Have a look to BENCHMARK products (BQ 20xx ... 2018 ??? )

http://pdf.alldatasheet.com/datasheet-pdf/view/26773/TI/BQ2018.html

... probably your chips are there.

Best regards
Alain

[lazy-b]

Alain, WOW....thats a fast respond.....Yes, have also seen the Benchmark Battery Management IC's.

The First 8 pin chips is AT12S8232P
The Second 8 pin chips is TPC 82031A

I guess, its more simpler, just make my own battery level indicator using the LM3914 ICs.

It so happen I got lots of Lithium-Ion battery 4.2Volts 1400MAH....bought it at a surplus store for only USD 1 each.

There are so many Battery Management IC find in the Net.

Thanks
Ellion

[Acetronics]

Hi, Ellion

AT 12S is a µP from ATMEL and TPC the header of TOSHIBA ( and its famous 60's toasters ... )

http://pdf.alldatasheet.com/datasheet-pdf/view/88395/TOSHIBA/TPC8203.html : semms a good choice !!!

So ... no hope to use an alternative choice batt !!!

I've seen lots of Li-ion batt level indicators on the Web ...

Alain

[lazy-b]

Alain,

Thanks for the Link......I guess, its not worth it trying to Reverse Engineering a Battery Circuits of CANON BATTERY PACK, just for a battery indicator in the LCD screen.....I guess, just make a separate Battery indicator would be a better choice, or just bought a new Battery Pack......its just very expensive here in the Philippines. a brand new CANON Battery pack cost about USD 80, its a lot cheaper if bought it in the USA, but if you consider a shipping cost to the Philippines, I guess its would be almost the same price........or just make your own for only USD 2.

Ellion

[lazy-b]

Guys: have found a better solution, I just add extra lithium-ion battery to the original CANON BATTERY by connecting it in parallel, I just charge both Battery to fully-charge, then connect the 2 battery in parallel using 3 pin male/female connector. now by Video Camera can be use much longer......its just little heavier.

I just wonder what will happen if I connect a Fully Charge Lithium-Ion Battery to a Half Charge Lithium-Ion Battery?

a full charge Battery will Act as a Charger to charge a Half Charge Battery, charge current will depend in the Internal Resistance of Both Battery......I guess, its safer done on Lithiu-Ion battery cause Li-Ion has a higher resistance compare to Nicad/Ni-mh or Lipoly battery.