Battery watch for LiPos

[Kernwrech]

I have been searching for this kinda thing for weeks, but the only battery watches I have been able to find are rated for 4,8 or 6 volts. I need to build a lightweight (preferrably under 5 grams) battery watch that can indicate the condition of the 2s Lipo pack. How else would I know if the cell voltage drops below 3 volts?

Are there any scematics for this? The simplest way would be to just hook up some zener diodes, serial resistors and LEDs, but I dunno how reliable this kind of system would be... Maybe I could combine the navigation lights and battery watch system in a way that nav lights are turned of when battery hits, say, 3,2 volts. Then, when it reaches 3 volts a red warning light would start to blink or something... What would be the most sensible way?

[leu1]

http://www.rcgroups.com/forums/showthread.php?t=221018&page=29#post6919897

[Sympster]

What about this:

Link (https://www.unitedhobbies.com/UNITEDHOBBIES/store/comersus_viewItem.asp?idProduct=4175)

It will monitor individual cells from the balance connector. You can use it as a 3 or 2 cell monitor. Indicates when you go below 3.2 volts per cell. They say it has a package weight of 17 grams but that's shipping weight. It looks very small and probably weighs close to your 5 gram spec. You can't make it for $1.95 and $3.00 shipping.

Good luck,

Sympster

[poulsbobill]

I use this. Battery Alarm ( http://www.webx.dk/rc/lipoly/low-volt-alarm.htm) I weighed it once...very light. I use 1 led.

Bill

I just weighed it...4.5 grams with a jst connector and 6 " of wire