Volt Ammeter
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Volt Ammeter
Resurrect Dead NiCd compaq presario cq60 Battery?
Hi I have dead NiCd battery that measured 0 volts.
No matter how long you put this thing in the charge, it just woudn't hold any charge?
Is there any known way to resurrect this battery? Non-commercially?
Best Answer - Chosen by Voters
It's rare to see a *true* ZERO (even a little voltage disqualifies it from the following explanation, so I'm trusting you here!) due to a cell failure in a battery pack. If the charger is working, you either have an internal open circuit or other charging circuit problem in the battery or one sorry battery that isn't going to be "resurrected". If the charger works, only checking of wires or cutting into the compaq presario cq60 battery pack can tell you if it can be "fixed".
a) First, check the charger to assure it is actually providing voltage. The only proper way to do that would be to place the meter across while charging to assure it was holding a reasonable float voltage (should be a fair bit above rated battery voltage). Ideally, you'd want to measure current with an ammeter in series, but that's not as easy to put together in most cases. If nothing can be readily measured with the battery in place, at least take a meter to the charger to see if you can pick up float voltage. There's no assurance with that measurement alone (could be being pulled down to zip even under a slight load) but it's better than nothing.
b) You say "battery" and not "cell". If it's a presario cq60 battery pack of some sort, it may well have internal charging circuitry (some contain "intelligent" electronics) -- or at a minimum, should have a temperature cut-off device (thermal breaker) to avoid any dangerous overcurrent conditions during charging or use. The charging circuit or internal breaker *may* have failed. Further, if it is a true "battery", the cells are internally bonded together. It's not common that these bond straps break (they're usually spot welded to the cells), but hey -- anything is possible.
c) Don't assume it's the battery itself that has failed (again, assuming it's not just a single cell). You may have lost an internal connection or may be dealing with a loose external connection. If it's one of those packs that come in a portable phone or R/C car (just as examples), a tiny tug on the wiring between the battery and connector may provide a surprise, and that'd give you zero in a hurry.
If the charger is good, and you can't sort out the problem, and it's some sort of compaq presario cq40 battery pack that's a bugger to replace, you can take it to a place like Batteries Plus to have it rebuilt with new cells. While you're at it, you might also consider switching them to NiMH for better capacity and lack of the "memory effect" that is a problem for NiCd cells.
About the Author
Good to buy laptop parts:
http://www.battery-center.net/
http://www.brand-new-battery.com
To find , the potential difference between two points, we use?
1.ammeter
2.volt meter
3.volt ammeter
4.galvanometer
Answer: 2. Volt meter
An ammeter measures current, a voltmeter measures the potential difference (voltage) between two points, and an ohmmeter measures resistance. A multimeter combines these functions.
Dr. H
Arduino Ammeter
