If a cap cannot hold a charge does that mean its dead?
when its hooked up my dmm reads 16.5v but when i disconnect it discharges at a steady rate til dead, takes roughly 10 minutes.

 

If the cap is isolated from a circuit (not just your DMM) it should be able to hold a charge for a LOOOOOONG time (weeks or months) until internal leakage consumes the charge. But if there is any portion of a circuit connected to the cap it could provide a leakage path between the + and - posts (16.5V... is a pretty high alternator setting)

 

Well i had it connected to a little batt charger. The charger showes 11.85v-12v when not connected to anything, once i connect it to the cap it showes 16.5v-16.8v. The cap then discharges from 16.5v's all the way down to 0v's when i unhook the charger.

 

correct me if im wrong,
im not a capacitor expert but i dont think i cap contains much power i know it can release what it has verry quickly the cap you have lights up when theres change in current (i think) so the change in current changes because you unplug it from your charge device theres a draw on your cap now cause theres no outside power going to it and the light on your cap is telling you your voltage and it dousent turn off because the voltage reader is eating power and the voltage reader stays lit when there is power leaving your cap???
like i said please dont trip if im wrong.

 

ou, and the voltage reader eats up all the power in your cap so you should see your numbers go down slowely, this is what my stinger cap dous anyways.

 

The cap i have is a lightning audio, doesent have a voltage display on it, i watched voltage go down with a DMM.

 

^ Sounds pooched.

 

Ya i figured, but i wanted to ask just to be sure before i "recycled" it

Thanx guys

 

1. What size cap is it?
2. What make/model DMM?

 

Sounds like the insulating layers are starting to breakdown causing internal leakage, so now it's just a load on your electrical system, so recycle it. This isn't very common to my knowledge at least with the large caps we use in car audio. The caps I use must be over 15 years old and hold a charge for months. Small caps on the other hand (like in your computer ) fail quite often usually do to excess heat ,so is it possible your cap is getting overheated from some external source, amps maybe or direct sunlight? Hope this helps maybe you can extend the life of your next one. Rob