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As Mocky said, the auto chargers will not charge if below a certian voltage, this is more so if the battery is a calcium type. However if it has been indicating a boost rzte for a long time it is nearly certian the battery has a dead cell at the min.
Cheers Scott
Well my multimeter arrived, useful bit of kit.
The battery is another story tho, couriers and barges don't readily transport batteries, so I'm going back to the mainland on Sunday morning and thank goodness Caterpillar are open 24/7, 7 days in Brisbane so will pick up a new battery quoted at $245.47.
I'm still topping up this old battery and it is all over the shop, but can keep it going till Sunday by the looks.
My multimeter results follow:
"what nanocom shows it's not direct battery power, it can drop along the circuit untill the OBD plug"
sierrafery you were right the Nanocom measures the battery at 12.26v and the multimeter says 13.3v directly on the battery when not connected to the car, so approx. 1v drop to the obd plug. Further I measured the resistance as per the video and I got a reading of 15.56 ohms I think. Does that sound right?
I think that the multimeter is reading high then cos above 13 on a disconnected battery is high, watch again that video cos you have to measure amps not ohms
Had to wait 1.5hrs for slabs. Watched video again. I was reading 15.56 milliamps before not ohms. Really had trouble getting a reading on resistance again, tried for ages, will try tomorrow.
Battery now on 12.96v both attached and unattached to car.
Most probably have to add GST to that quoted price.... be prepared.Quote:
Originally Posted by Islandnomad
sierrafery when I measured the battery at 13.38v via multimeter unattached to the car, it had been on charge the entire night before.
Battery lost charge overnight (was 12.96v) according to multimeter at 12.8v now still attached to the car, same reading unattached. According to Nanocom its 12.1v to compare, so 0.7v difference.
I wonder now that I have a multimeter, when comparing the Nanocom figures I've been reporting all week, if they were between 0.7 and 1v below actual battery voltage due to reading thru the Nanocom, whether this battery is actually alright at the moment? So Nanocom figures since RACQ jump start a week ago have been 11.89-13.0v if you add a volt or so, the figures are ok, aren't they?
Tried to do resistance test again today to investigate "parasitic drain or cos the battery is weak....or both" and was getting results starting v.high and reducing quickly and no consistent milliamp figure. Going to do further research today as any figure I post here I'm just not confident in yet.
Only way you can test battery now is old school high rate discharge test or digital battery tester, don't know if there is a decent workshop on the island but they should test for free
Cheers
IMO nanocom readings are a bit lower and the multimeter readings a bit higher than reality but on overall view it's quite OK... though i've never seen unconnected battery with more than 13V in itQuote:
Originally Posted by Islandnomad
Bought my new Caterpillar battery today $270, it is at 12.6v. Car and old battery (at 12.86v attached) now performing quite well.
Not surprised about voltage drop via Nanocom, however this new mult-imeter should be reading accurately shouldn't it, or I should send it back?
Will do battery load test tomorrow, now that I have a backup, and will log data as I go.
Batterys can read higher than 13 volts for anything up to a couple of hours after charging depending on battery and ambient temps until settled, islandnomad don't send your multimeter back just yet as it's probably accurate enoughQuote:
Originally Posted by sierrafery