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mctrivia
03-25-2009, 12:20 PM
I have 2 TL-5242/W Rechargeable Lithium battery backs but the datasheet does not say what max current draw is. Anyone know what the draw on these are? or know some small battery packs that can handle 2A draw. I only need to keep it running at full current for 20 min or so.

I can fit 4 Lithium AA in but they use up all my space and are not rechargeable.

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Need to make your prop design easier or secure? Get a PropMod (http://propmodule.com) has crystal, eeprom, and programing header in a 40 pin dip 0.7" pitch module with uSD reader, and RTC options.

Tracy Allen
03-27-2009, 06:33 AM
That is a memory backup battery. While it has a 2 amp-hour capacity, it is only rated for milliamp level current draw. From the attached data sheet, the peak capacity comes at about 200 microamps.

A better bet is one of the lithium ion batteries. Check out batteryspace (http://www.batteryspace.com). The 18650 cells have a capacity of around 1300 mAh, and peak current of around 2 amps.

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Tracy Allen
www.emesystems.com (http://www.emesystems.com)

mctrivia
03-27-2009, 07:05 AM
ya the data sheet i could find did not say max current draw but the diagrams had me suspicious.

Any suggestions on how to build a charging circuit?
This pack looks perfect. (http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=4425) should give me an hour at full draw and days at minimum.


the 18650 is the same battery used in the Spyder II lazer.
http://www.wickedlasers.com/lasers/Spyder_II_GX-26-0.html

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Need to make your prop design easier or secure? Get a PropMod (http://propmodule.com) has crystal, eeprom, and programing header in a 40 pin dip 0.7" pitch module with uSD reader, and RTC options.

mctrivia
03-27-2009, 07:17 AM
for any interested found this to charge single cell (http://www.linear.com/pc/downloadDocument.do?navId=H0,C1,C1003,C1037,C1078, C1088,P1825,D4460) does not work for me as i need a 6-12V rail as well as the 3.3V for prop.

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Need to make your prop design easier or secure? Get a PropMod (http://propmodule.com) has crystal, eeprom, and programing header in a 40 pin dip 0.7" pitch module with uSD reader, and RTC options.

mctrivia
03-27-2009, 10:58 AM
anyone know if this ic (http://ww1.microchip.com/downloads/en/DeviceDoc/21823c.pdf) would be safe to use all the time?

i.e. my application is plugged into wall uses this ic to charge my battery pack. my dual input switching supply (http://www.propmodule.com/?x=products_ps) auto switch between the 12V wall and the 7.4V battery back when the wall goes dead. When power is regained it charges the battery and leaves it there until the next time the power goes out.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Need to make your prop design easier or secure? Get a PropMod (http://propmodule.com) has crystal, eeprom, and programing header in a 40 pin dip 0.7" pitch module with uSD reader, and RTC options.