I think my 9 volt lithium is getting tired. the PIR isn't detecting anything beyound 25ft or so.
How and what readings should i get from a multimeter?? what is the low reading that i should replace it?? Thanks JHPers
Your best bet is to buy one of the battery testers that test under load. Just testing the voltage isn't always an accurate test. I bought mine from Menards for $5 and it tests AAA-D, and 9V plus it's small enought to fit in my pocket.
Menards is sorta like a Home Depot, I guess I forgot they are only in the Midwest. You can get them at Radio Shack and most other places that sell multimeters and testing eqiuptment. Just look for one that will test most sizes of batteries so you don't have to buy another one anytime soon. I'm not sure if they make a "special" tester for lithium batteries or not. Some of the advanced testers I have seen have a switch for types of batteries like NiMH, NiCad and Alkaline. It seems to me that Radio Shack has a large selection of testers to choose from, but they may cost more than $5.
(Edited by coyotebandit at 4:26 pm on July 15, 2002)
The battery testers are good but what I do is keep a cheap DMM in my camera backpack. You can either test the battery open circuit to see what the open circuit voltage is or install it in the camera and fire the camera while you monitor the battery terminal voltage. If the voltage falls below what is required to operate the cam it's time for a battery change.
I've been using C's and AA's in my cams. Frequently I'll change the batteries after a month even though they are still probably good enough for another month. I take them home and use them in flashlights until they die.
I'm looking forward to using the low power mods for the MS20. I'm going to 9V batteries. with them.
The 9 volt lithium battery should be hooked up to the same "raw" DC input that the other batts were hooked up to - not the 5VDC regulated power rail.
If I remember right, the 'dead' voltage of a 9V lithium batt is something like 6.9 volts or a bit more. You can try to drain it more, but the internal resistance of the battery increases at some (geometric??) rate as you pass that point. The detector might become unstable and fire off all the pics.
For best results in any circuit - try to keep your battery supply about .15 volts OR MORE above the regulators output voltage.