P80 Battery charge and surface charge measurements

Post by **abscate** » 08 Jan 2019, 09:03

While working on Evita the 99 S70 Ive got her battery on float.

After a couple days at 10 Amp charge setting, I disconnected it, then cycled the lights for 30 seconds and monitored voltage

Ambient temp approx 0C

After charger 14.5 Volts
30 seconds lights 13.5 Volts
30 seconds lights 13.2 Volts
30 seconds lights 12.9 Volts
30 seconds lights 12.7 Volts
30 seconds lights 12.55 Volts

I got bored here.

Post by **ZionXIX** » 08 Jan 2019, 15:12

I brought a battery back from the dead on a 2amp charge in 24 hours. My battery got low after storing the vehicle and the voltage went down to less than 1 volt. It sat there dead for several weeks. The charger wouldn't even recognize it. I hooked up my truck battery to the dead battery with the charger attached for about 30 seconds and disconnected the truck battery. This was enough to start the charging process and I was able to start my engine off that battery in 24 hours. It was reading 13.5 volts when I stopped charging. It settled down to about 12.5 volts a few minutes later.

Kraig · Post by **Kraig** » 18 Jan 2019, 20:39

Have had several "won't take a charge batteries" putting a small load touching horn/lights a few times and all the sudden needle moves a tiny bit.
Dropping them a few times on a cement floor a few times...seen at Interstate

Post by **jimmy57** » 18 Jan 2019, 21:36

I'd be hesitant to drop a battery as a means to help it. COuld it maybe "shock" sulfur off the plates? maybe. Could it shake the plate separator fiberboard sheet so it breaks and opposing pole plates touch? Yes, that is what happens to serious off-roader batteries so that those guys moved en masse to spiral gel cell batteries like Optimos were and now the flat plate AGM that are big as OE batteries now.
What is not "iffy" procedure is to make sure the battery has proper cell electrolyte level so the sulfur can be dissolved into water to re-form strong acid. Top up with distilled water is accessible if low. High and low cycle charging is a way to reverse sulfation. SOme new chargers have that as a feature but it is also possible by choosing your 10-20 amp rate for 20 minutes and then let it go trickle for a while, even overnight and then do some 20 min high, 60 min low cycles.
I HATE buying batteries. I get long life by charging the batteries in all the stuff I have, from 100 HP tractor down to riding lawn mower twice per year for 24 or more hours at a low charge rate for the battery size. 2A for riding mower 15A for the 1200CCA tractor. I have a fe chargers so I can do 6A for the 600-750 CCA bateries in XC60, Expedition, and the 850CCA pairs in diesel pickups. The tractor got 8 years on its battery, the riding mower did 12+years, Diesel pickups have usually done 6 years. Texas is not a nice place for batteries so those are great lifespans. It is a shame that all cars don't have batteries in trunk. P2 have good battery life in spite of the Amp hog slow to sleep ways. P1 and P3 not nearly so good with a battery sitting above engine to side of exhaust. Cowl as "cold zone"...my ass.
I'm waiting to see how long the 2004 V70R original battery, 15 years old now, goes as electric gate battery. It has been the gate battery for over 6 years. It didn't fail in the R but I needed a gate battery and the best decision was new to car, car to gate.

WhatAmIDoing · Post by **WhatAmIDoing** » 18 Jan 2019, 22:19

I have seen people bring lead acid batteries back from the dead by inverting, shaking, and then trickle charging for 24 hours. Not sure I'd do this unless desperate. Especially not if it was going back in my daily driver.

Post by **Rattnalle** » 19 Jan 2019, 00:48

They'll never be as good again if they've died once so it probably depends on what you require from it. I won't risk the car not starting a cold winter day since I use the car mostly for long trips and I could be wherever when it happens. I hook up the smart charger for a day or two every once in a while to make sure I don't go there.

Post by **abscate** » 19 Jan 2019, 01:41

SWMBO X3 definitely goes to charge deficits in the depth of winter.. 8 minute commute, town traffic, lights on there and back. In Jan and February I pop it onto a charger once or twice to keep the battery happy

X drive is really unhappy with low B+

Post by **Rattnalle** » 19 Jan 2019, 02:43

8 minutes is about what my commute is as well. Or 11-12 by bike. Needless to say I don't drive when I don't need the car for other reasons. For both my sake and the cars'

Post by **abscate** » 19 Jan 2019, 04:29

Bike would be nice. We aren't well set up to share the road with bikes, neither roads nor drivers. Big hill too, which I wouldn't want to climb on days ' end

Post by **Rattnalle** » 19 Jan 2019, 08:14

abscate wrote: ↑19 Jan 2019, 04:29 Bike would be nice. We aren't well set up to share the road with bikes, neither roads nor drivers. Big hill too, which I wouldn't want to climb on days ' end

That sucks. People are often dicks here too but I mostly cut through residential streets.
I've got an uphill all the way home, but better home from than to work