DSTE Travel Charger teardown

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Daniel Wee
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DSTE Travel Charger teardown

Post by Daniel Wee » Tue 15 May 15 2012 7:40 pm

The BLN-1 replacement batteries came with a "DSTE" branded travel charger. I have read about the shoddy design of chargers and low power devices coming out of China and decided that it might be best to take the charger apart to see what makes it tick.

Daniel Wee
Site Admin
Posts: 2073
Joined: Wed 25 Feb 25 2009 8:00 pm

Re: DSTE Travel Charger teardown

Post by Daniel Wee » Tue 15 May 15 2012 8:19 pm

Photos of batteries and charger.
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Daniel Wee
Site Admin
Posts: 2073
Joined: Wed 25 Feb 25 2009 8:00 pm

Re: DSTE Travel Charger teardown

Post by Daniel Wee » Tue 15 May 15 2012 8:24 pm

The MC34063 is a common switching boost/buck regulator.

We also see a full-wave rectifier on board and what appears to be a step down transformer.
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MC34063A-D.pdf
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Daniel Wee
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Re: DSTE Travel Charger teardown

Post by Daniel Wee » Tue 15 May 15 2012 9:24 pm

Charger open voltage is 8.403V. This should represent the CV stage. The question is if the CC stage will allow the voltage to any higher than 8.4V.

For the record, Li-Ion cells have a variety of terminal voltages depending on the chemistry. Standard cells, however, are typically maxing out at 4.2V per cell. For a 2S cell, this would be 8.4V.

Daniel Wee
Site Admin
Posts: 2073
Joined: Wed 25 Feb 25 2009 8:00 pm

Re: DSTE Travel Charger teardown

Post by Daniel Wee » Tue 15 May 15 2012 11:03 pm

Battery innards reveal that the capacity is actually 1020mAh and not 1450mAh as claimed. They also do not look like Sanyo batteries. A 10k resistor is soldered from the "T" tab to ground but does not fool the original charger.
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