picoscope battery test

Is the pico battery test software reliable enough for testing of battery's using just an amp clamp and scope connected to battery ?could someone move this to correct section please ..posted it in wrong one :oops:

No problem Just moved it

Thank you.

Did you see the video from Eric ( South Main Auto Repair) ? This is were he performs a battery test with the Pico. Haven't tried it myself but seems to work fine...

A good test especially if you suspect more than just a simple battery fault or are already doing a cranking compression test
But if it is just the battery you want to test to just to use a a digital tester the works on the AC impedance of the battery the basic models don't cost much and as well as a simple pass/fail they give an estimate of the efective CCA of the battery and the perecentage of the remaining life feft in the battery.





Any doubt and I usually follow up with a high current load volts drop test. To be valid this type of test has to load the battery to around 1/3 of its' CCA or 3 times the amp hour rating of the battery.
Because batteries even on small cars are getting much bigger the old hand held load testers which will generally only load the battery to 100 amps are too small to and a carbon pile tester is required to load the battery enough to reveal a dead (gassing) cell. A battery with dead cell will generally first give trouble in the first cold snap of winter, once the car has been boost started and immediately afterwards will generally start and run normally and may not give problems for weeks or months. The key off engine off voltage across a battery with a dead cell will be only slightly lower than normal but when it is placed under very heavy load the voltage will drop instantly below 9v to around 6 volts.

With a dead cell when a very heavy load is put on the battery the voltage drops almost instantly from only slightly below the normal 12.5 to 12.7 volts to 6 volts or so. As the battery heats up due to the high current the voltage may rise 2 volts or so.

Continued:
The Pico software is superb but even the cheapest scope will do the job the difference is you don't get a nice print out to hand to the customer and you have to interpret the trace yourself.
This capture of a start up with a good battery was taken with a Velleman scope reading the voltage at the cigar lighter socket.

You can also use an scantool--- same vehicle different startup captured with OBD Car Doctor Pro

Hey Andy ,thanks for the detailed answer, some great info here.
@Dylan yes i saw that vid.Was wondering if it was a reliable enough test to say yes you need a new battery etc.I have a 2 channel pico and forgot all about the battery test software i had so i will have to give it a try.I bought a new battery a while back so I'll see how it performs.

scopeman wrote:

@Dylan yes i saw that vid.Was wondering if it was a reliable enough test to say yes you need a new battery etc.I have a 2 channel pico and forgot all about the battery test software i had so i will have to give it a try.I bought a new battery a while back so I'll see how it performs.

Ok nice! You have a Pico so why not use this specific test right? Definitely agree with Andy that if you don't there are other ways to check, like he posted here on the forum.
Keep us informed!

If you have a reasonably decent volt meter you can get a good idea of battery condition with a few simple tests my Dad taught me.

1) Standby voltage about 12.5V
2) Charging voltage about 14V
3) Cranking Voltage about 10V
4) Engine off, headlights on high beam - voltage will drop a few tenths of a volt when headlights turned on, should drop very, very slowly. If you see it dropping a tenth of a volt every 30 seconds the battery is bad (assuming it was charged properly.)

These tests will not capture every battery fault but do a good job generally. As a shade tree mechanic if I am still uncertain after these tests I'll take the battery to have it tested on a load bank.