Li-ion Power Pack Question

xanadu

http://www.parallax.com/StoreSearchResults/tabid/768/List/0/SortField/4/ProductID/782/Default.aspx?txtSearch=battery+pack

Can this pack provide power while recharging the batteries? I would like to use it as a fail-over, so I would need it to be able to produce power while charging, and of course when not charging with no loss of power in-between.

Thanks.

Publison

xanadu wrote: »

http://www.parallax.com/StoreSearchResults/tabid/768/List/0/SortField/4/ProductID/782/Default.aspx?txtSearch=battery+pack

Can this pack provide power while recharging the batteries? I would like to use it as a fail-over, so I would need it to be able to produce power while charging, and of course when not charging with no loss of power in-between.

Thanks.

No, according to the specs:

Upon application of +5 to +12 VDC to the Charging Power Input jack (J1), the following happens:a) The Charging Power Input (Green LED) is activated.
b) Each cell is electrically disconnected and isolated from the other.
c) The Cell Power Output jacks are disconnected from the cells, and disabled.
d) The dual charging circuits begin a qualification mode to determine each cell’s characteristics.
e) After checking the cells, LED status indicators are activated. If required, each cell begins
charging their respective cells.
When Charging Power is removed, it results in the following:
a) Cell charging circuits are disabled and Status indicator LEDs are disabled.
b) The cells are electrically connected into a series configuration.
c) Cell Power Output jack is connected to the cells, resulting in a 7.4 VDC (max.) output.

Cell Power Output: Polarized, right angle, female, bottom pin positive.This Power Output jack is the output from the cells.
When there is no Charge Power Input (i.e. when the wall charger is disconnected from the PCB),
the two 3.7 volt cells are electrically connected together in a series configuration, and the
resulting power (3.7 VDC x 2 cells = 7.4 VDC) is available at this jack.
Upon application of Charge Power (such as from a wall transformer), Cell Power Output is
disconnected from the on-board cells, and this jack is disabled.

HTH,

Jim

xanadu

Thanks for clearing that up. I see the other charger has that capability - http://www.parallax.com/portals/0/downloads/docs/prod/hardware/28986-Li-IonPowerCharger2cell-v1.0.pdf (last page).

Publison

xanadu wrote: »

Thanks for clearing that up. I see the other charger has that capability - http://www.parallax.com/portals/0/downloads/docs/prod/hardware/28986-Li-IonPowerCharger2cell-v1.0.pdf (last page).

You are correct sir!

I didn't realize there where two chargers, (Parallax just keeps pumping them out)!

Aux. Raw Power Output: Polarized, right angle, female, bottom pin positive. This connection can beused to power another device. For example, you can charge the Li-ion cells and operate another
device from the same power supply. When you plug in wall-transformer (to charge the Li-ion
cells), you can use the Molex/barrel jack cable to provide power to another device (such as a
Board of Education, Propeller Proto Board, etc.) This is not power from the cells. This is the
same power that is charging the cells, via your charging supply input on the Charge Power Input
barrel jack.

Jim

Matt Gilliland

Hi JonG - You'all are exactly right-

The little board had too little real-estate for the extra jacks necessary, plus we wanted to keep the price on that one down as low as we dare...

The ApNotes in the big one show its versatility...
-Thanks for jumping in Jim!

-Matt