Parasitic drain, an automotive short circuit that may cause a recurring dead battery

I describe a practical algorithm for diagnosis and investigation of parasitic drain in an automotive electrical system. This problem typically presents with the recurring problem of a dead battery when the car is parked and not used for hours to days. Parasitic draw is a low amperage, high resistance short circuit that persists even when the ignition key is turned off.


This video is published for entertainment purposes only, and it is not to be construed as an instruction guide. If you need help with an automotive problem you should carefully assess your limitations, and consider consulting a professional before getting in over your head. Be careful to protect yourself and to protect your property by not doing something you are unqualified to do....

Category:

Autos & Vehicles

Tags:

• parasitic drain
• parasitic draw
• dead battery
• dead car battery
• recurring dead battery
• automotive
• DIY
• automotive electrical problem
• electrical circuit tester
• short circuit
• automotive short circuit
• repair

[hailapeste]

I doublewatch your video coz it contains more the one tutorial inside. My question is can you elaborate on Cold Cranking Amps and Reserve Capacity numbers on battery coz I want to understand more of my battery 55A with 255DIN (GM) I know what 55A means but 255DIN dont. tnx

[spelunkerd]

@hailapeste That's a GREAT question. But it will take me a few weeks to find a good answer, ha ha. I googled 'car battery comparison', and came up with a few links. CCA is the important one here in Canada, since new cars are using more and coming close to the limits of cold usage. Thanks for your input! If you find out more, please post it here.

[hailapeste]

Very useful video, keep going. I thank you especially for 1ohm good explained method coz I have a cheep multimeter and I need to use it for this purpose. Still I'll try to find a little strong resistor cca 15-20w.

[spelunkerd]

@hailapeste You're welcome. And you also make a good point that the power rating on the resistor is very important. A higher wattage resistor would be better, but they aren't sold in many electronics stores, whereas the one Scotty uses is readily available. Just remember that you just let the juice flow long enough to get a reading, then quickly take it off before it gets hot.

[worldstream]

@spelunkerd You're right about calculated 10w should be enough according to this time span. I was thinking to actually build one resistor from NiFe leftovers. :) Your channel has allot of good quality infos. thx

[spelunkerd]

@worldstream Thank you. I had a look at your stream as well -- are you from Romania? Youtube is my chance to meet intelligent people from all over the world.

[sxr951]

Batreee..

[worldstream]

@spelunkerd I've spent quality time with quite some of them. Many romanian peoples have entrepreneurial mindset but don't know where to start. I just explain them the basics. I'm looking for the next episode.

[jayguy173]

i got several shorted circuits improper terminology

[spelunkerd]

@Toltecatl Above all said, I still prefer to use the ammeter function of my multimeter, but I'm very wary not to overload the current draw. If I think the current may be too high, I'll use my induction ammeter which will not die if current is high. The resistor method is cool and interesting but I don't often use it. If I had an older multimeter, or one with a blown ammeter fuse, than I'd use Scotty's method.