1999 v70 NA battery drain

[abscate]

Been fighting a dead battery problem onShagg this summer.

Problem. Over about 10 days , battery goes to discharge state of no crank , dead or gremlin dash lights

Usage pattern Hard use. Car gets driven 1 miles to work and back daily, little on weekends

Work performed.

UBG alternator removed from running car
New battery from NAPa
New positive cable
New negative cable
Starter replaced with tested spare
Passive draw is 30 mA

Still dead after about 8-10 days

Beat idea now is marginal alternator with short drive cycle

I have to get this solved before winter

[volvolugnut]

Drive 10 miles each day. Better for battery and will warm the engine/systems.

volvolugnut

[BlackBart]

What is the charging voltage at the battery while running? Is it the alternator?

[scot850]

Battery is not getting a chance to recover after starting the car. It will need a battery conditioner to keep it charged and battery in good condition. It will get worse as weather gets colder and heaters on, lights and the rest.

For a mile, do you need a car?

Neil.

[foggydogg]

When the Redheaded Problem Child arrived, it had a phantom draw that killed the battery in about the same time frame. Walking past it in the semi-dark garage one day, I noticed the red glow of the door-edge light on the right rear; the contact in the latch had gone wonky, but just for that light; it didn't throw a 'door open' warning. Application of the usual chemistry and a bunch of manual cycles, end of that particular problem. Easiest fix on the whole car.
My guess is you have already pulled the glove box light.

[abscate]

The 30 mA diagnostic as ruled out phantom drain, unless something is turning back on after key put

[abscate]

Update

After run down to Long Island

Battery at 12.5, off, 85% at ambient
At idle , 13.8 volts system voltage

She hasn’t had trouble cranking adding 5 minutes to commute. It looks like a straight drive cycle issue

We will install a 5A battery charger and top off battery weekly and during cold snaps below 20F

[MrAl]

Hello there Steve,

Get rid of the NAPA battery and get a real one instead. I had same problem with my old Hyundai when i got a NAPA battery.

Ok so when did this first start to happen? That will tell us a lot.
These cars have to have a battery that is specified for this car by the manufacturer, but i dont trust NAPA batteries. I'd go with Interstate. The newer batteries have a higher voltage charge requirement so the ones we can use have to be the older type and i dont think NAPA knows that or something.

The way to find out isnt too hard, but you need a clamp on DC ammeter. 30ma over 24 hours isnt much so it's got to be the battery.
Over 24 hours it's around 3/4 ampere hour, over two days it's about 1.5 ampere hour, over two days around 2.25 ampere hours.
Now just some examples, if your car is charging at only 1 amp, it would take 45 minutes plus maybe another 10 or fifteen minutes because of the charge inefficiency, so say 1 hour. If it is charging at 2 amps, it would take 30 minutes, at 4 amps, 15 minutes, at 8 amps, 7.5 minutes, and at 16 amps about 3 minutes 45 seconds to recharge. I doubt it is over 16 amps.
So you see the possible problem, and this is bad if the battery is not the right type for this car because the charge current will be too low. The wrong type i think is the AGM type. These cars charge at a voltage that is too low for that type i think, and it's been my experience that is the case.

If you can use a battery maintainer daily then i dont think you'll have a problem because that will recharge the battery enough. With my old Hyundai i had to bring the battery in about once a month or every two months something like that and charge it up in the house. Lucky it did not have that dang OBDII so it had no computer (1988 Hyundai had no OBDII). WIth that car if i didnt do that eventually the battery would be too low to start the car.
The drain on that car was very very low, i believe it was even less than 30ma.

So the best test i can think of is measure the charge current while idling and see what it is, and i would think it should be at least 10 amps but even 5 amps might be enough. I would dump the NAPA battery though i'll never get another one of that brand and if you take it to them they will but a dumb tester on it and say it's good.

Please let us know what comes of this should be interesting.

[abscate]

We are still wrestling with this one. I’m slowly moving from one hour to 3 hours away so it will be harder for me to deal with it but..,

Current diagnosis. Weak alternator coupled with short drive cycle

Action plan.
Install 5 amp battery maintainer
I’m having two alternators rebuilt and will swap in a refurbished one
Caitlin will add a 20 minute loop to her commute one day per week

[scot850]

Caitlin needs to find a food store 20 minutes away and do a round trip once a week!

Neil.