Battery testing questions Topic is solved

Post by **scot850** » 10 Apr 2018, 15:53

Sorry for the ramble!

Well my new PITA 00 V70 NA/base is determined to stick around and throws more and more toys out when ever something is fixed to prevent it being sold.

Just spent another $1200 to get it through the insurance inspection. Then the dealer had to do an alignment following replacing the inner/outer RH tie-rods. So it passed the test and promptly failed on alignment as the RH rear delta link adjuster for the LH axle was seized solid (why do the idiots at Volvo keep putting steel bolts un-sleeved through aluminum!?). Had to wait for parts so car sat for 2 days (I had charged the battery on a trickle charger before taking to the dealer), then another day as wrong parts delivered, and by then too late to collect on Friday. Got a call first thing Monday. Your battery is dead. Only giving 19% charge. Do you want us to fit a new battery?

Er, no! I'll bring my spare Volvo battery. Did you check it for charging system. Yes, all is good.

The battery is a Crappy Tire (Canadian Tire) battery fitted by PO just under 2 years ago. Rip-off warranty is for original purchaser only, so why bother warranting it?

Fitted the old spare Volvo battery (having checked it and charged to full). Ran home and checked it with multi-meter. It read 12.2V low but ok. I have checked it again several times over the last 24 hours and it has stayed the same.

I fitted my battery tester to check it and it reads 12.6V, but when load tested (it is set for 600CCA as per battery label) it says the battery is weak. Is that true? How do I know? I disconnected the negative lead and looked for current drain. This is were it gets weird.

When set to 200mA scale, it initially reads about 130mA, but then drops down to around 13-20mA. The weird part is it fluctuates up and down to a minimum of 13mA approx. Why would it fluctuate? I tried another digital meter and it does the same, but read 12.6V?

As many of you regulars know I am an electrical luddite, but I'm sure when I have done current drain tests in the past the reading is fairly static.

Now I connected the Crappy Tire battery to my smart charger and it normally starts at 4A and then adjusts as it reads the battery condition. It usually drops current loading fairly quickly. I checked the %age remaining load in the battery and all it read was LO.

I left it for a while and came back and I could hear the charger cooling fan working hard. It was charging at 6.1A! It still read LO.

Checked again several hours later and it was down to 1.0A and at 90% charge. This morning it reads fully charged.

I tried my battery tester and it also said the battery was weak, and at 13.2V.

I took the battery back to Crappy Tire and had them test it with their more fancy tester and they said the CCA was 702 and the battery was ok (they won't replace it even though it is not 2 years old as I was not the original purchaser!).

Not sure what to believe here. Do I have a problem with the car, the battery(s) or am I worrying unnecessarily?

Sorry for the ramble, but don't want to sell a car with a problem, but not sure it has. Can't explain why the battery drained at the dealer when it was ok on the Friday afternoon.

Thanks,

Neil.

Post by **abscate** » 10 Apr 2018, 19:34

13.2 volts and 700cca...good battery

The kid at Volvo ran it down listening to lady Gaga singing Elton John

Post by **scot850** » 10 Apr 2018, 19:45

Thanks abscate. I am now monitoring the old Volvo battery for signs of voltage drain for the next couple of days.

Can 2 x current draw tests significantly draw down even a good battery? I put the 'good' battery back on the 'smart' charger and it read only 80% charge. It started charging at 4A and was probably down to 2.0A by 20 minutes and FULL and 0A within about an hour or less. Appreciate that no measuring with these devices are 100% accurate, as battery now reads 13.07V on my 'good' multi-meter. I will continue to check it over the next couple of days and if no major change accept all is ok for now. Car can then get washed, pictures taken and hopefully up for sale by the weekend with some luck! Mind you, rain/snow and warm weather means the car will not get back from the wash any cleaner than now and we are not allowed to wash cars in driveways.

Oh, well.

Final thing is the strange current draw reading? Is that normal?

Neil.

Post by **abscate** » 10 Apr 2018, 20:17

Light up a small lamp for a minute to remove surface charge before measuring voltage. If you measure it right after charging it can be a false higher reading.

That two year old battery should still be good

Post by **scot850** » 10 Apr 2018, 20:31

Thanks for the note. I will do that and thought that may be the case, so will really use the next reading as the base line.

Still doesn't answer the weird current draw with the battery in the car with the negative lead removed. Battery is the old Volvo one that has been in the car for 36 hours.

Neil.

Post by **misha** » 11 Apr 2018, 02:07

If negative battery cable is disconnected...there could be NO current draw,or parasitic draw by the car.
That simply means that battery doesn't hold the charge....meaning....the battery is bad.
After the battery is fully charged,you need to allow it to cool down for min.2 hours before measuring the voltage across terminals.Only after 2 or more hours it will settle down and show you correct voltage.Sitting overnight after charging would be ideal.
Battery can be bad after 2 years....nothing strange about it...especially cheap ones.

Post by **scot850** » 11 Apr 2018, 08:24

Thanks misha. Well aware the battery can be bad quickly. I saw several bad reviews on this brand with one guy replacing 3 in 3 years. But then again there can be car issues that cause batteries to fail! Checked the voltage on the battery after maybe 2 hours and it dropped slightly to 12.97V. Will check again this morning. This battery is NOT in the car.

What I am trying to figure out is why the variability of the current draw with the negative lead disconnected and running a meter between the terminals. It is like there is something initially draining and then it fluctuates by about 10mA. When I have tested other P80s I have owned I tend to get a steady reading. Maybe it depends on the meter, but this happened with 2 different ones.

Neil.

Post by **abscate** » 11 Apr 2018, 08:27

10 mA is a really light draw, Neil - do you have a hard connection of the meter leads or are you holding them on. A small resistance change might be the cause, like corrosion at the contact point.

12.97 after rest is a nice healthy battery voltage - they can fail at good voltage and no capacity but a cranking test would confirm/rule out that.

Post by **misha** » 11 Apr 2018, 09:20

Yes...it can show correct voltage but as soon as you crank the engine it can fail....it is rare case but it can happen.
It's all about battery quality.
I find that Energizer batteries are the best.It lasted about 6 years in my car while other brands i used couldn't last half of that time.
If it doesn't hold the charge...it's simple...it is bad.
If your multimeter have low batteries and indicator is displayed....it can display strange readings.

Post by **scot850** » 11 Apr 2018, 10:16

Ok I'll check the meter batteries, but while anything is possible, 2 meters doing the same would be unusual.

Checked the original battery from the car following removal from charge last night. it now shows 12.82V, so has dropped from measuring immediately on removal of charge from 13.07V to 12.82V in about 14 hours. I will continue to check as it is not connected to anything and see if there is any change in the next 24 hours. If not I think I can assume it may be ok.

Checked the Voltage on the battery in the car and it was 12.56V about 14 hours ago and now shows 12.52V. Again I will check again in 24 hours and continue to monitor for a few days. At the rate the in-car battery is draining I may be a little early saying it doesn't look like a major drain is going on. I know my other P80's have varied from around 10mA to 60mA of drain, so assuming the norm for this car is 15-20mA that is ok in my book. I'll update if anything changes significantly. I'll then have to work on the assumption someone left something running at the dealer.

In terms of batteries, I have used mostly Interstate here (which is the OEM Volvo in Canada). I changed the battery out on our 2006 XC70 last fall as I did not know the age of the battery and we have had the car for 7 years and I have no record of a change before that that I can find. I previously swapped out a 9 year old battery from a 760 Turbo I had 15 years ago that had started to fail, and the same with a 1999 Audi A4 we had that had a 10 year old battery when it started to fail due to lack of maintenance by the dealer (it was almost dry although the checked off it had been inspected at every service).

But quality is the key. I removed and replaced the battery in my 03 4Runner as the dealer said it was weak. It is a Panasonic OE Toyota battery. A new battery from the dealer was $260 CDN, whereas a higher rated Interstate from local supplier was $160 CDN with a better warranty. Swapped the battery out and although it said it was 'maintenance free' all it has was stickers over the access holes on the top. I removed those and added distilled water (it was below min. mark) and charged with my smart charger. It charged fully. Took it to get the core refund and had it checked and they said the battery was still strong and good to go so it came back home.

Thanks.

Neil.