Help diagnosing parasitic drain or faulty charging

[towtruck]

Hello everyone..

I am taking over maintenance oversight on my parent's EV due to my dad not being able to. It's a 2003 with the camper top but otherwise a basic passenger van inside. Oh, and 31k miles, well maintained, garaged, etc.

My mom got stuck a couple times with a drained battery. The battery is about 1/2 year old, and was tested at AutoZone & came out looking great, so I'm suspecting either a parasitic drain, or improper charging.

I studied up on how to detect parasitic drain, and it seems straightforward, except that the articles mentioned that some vehicles "have several computer modules that remain online for 30 minutes or more after you've shut off the engine and removed the key from the ignition switch."

My primary question is whether the EV is one of those vehicles. Apart from that, any insight that you could give regarding the particulars of checking for parasitic drain on the EV would be helpful.

I haven't found any articles specifically on how to check for correct charging, but I assume that if there is no parasitic drain, then the charging system is the culprit. Any thoughts?

Thank you all for your time!

[TDCTDI]

How old is the battery?

What type of battery? Is it from the dealer or one of the “Never Start” AZ batteries?

Get a battery from the dealer, they’re about 30-50% heavier than the crappy FLAPS batteries.

Many time I’ve had people complain that their cars had charging issues because AZ tested their battery & said it was fine (especially if there was an AZ battery in the car, they like to sell new stuff instead of warranting stuff they already sold) I replaced the battery & the problems went away.
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[Abscate]

The mileage is so low that it obviously sits for long periods of time. It needs to be on a trickle charger or else your new battery will die, too.

I don’t believe the T4 had modules Which stay live, that came later in most other brands.

Put an ammeter I series with the removed negative battery terminal and ground with all the doors closed. WAit five minutes after the hood is up.

I’ll measure my current draw today and report
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[towtruck]

Thanks to both of you!

The battery is an Interstate, 1/2 yr old when the problem started, so I'm skeptical that this is the source. And the van has sat for extended periods for most of its life without the kind of problems we're seeing now. That being said, I've told my parents to drive it at least once a week, and I'll be taking your advice to put it on a trickle charger, which I have at my place and just need to bring to theirs.

Thanks also for the information about the modules and waiting 5 min after the hood is up. The info about your draw will be a very helpful reference point.

Thanks again!

[Abscate]

After disconnecting the negative on my 2002, it drewabout 150 mA for a few minutes, then settled down to 40 mA ( 0.040 amp)

That’s probably an ECU reset and then immob baseline draw
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[towtruck]

Awesome!

I'll do a check next time I get to my parents house. It may not be before next weekend, but I'll report back when I do.

Many thanks!

[marshy11]

One way you can diagnose a parasitic draw or electrical malfunction is to disconnect the negative battery terminal and connect a test light between the terminal and the cable. Light on means current is flowing. Start pulling fuses and relays (one at a time) until the light goes out and there's your draw. Keep in mind an open door light switch will draw current.

[towtruck]

Merry Christmas everyone!

Sorry I've been gone so long. My parents told me "it's fine now" a while ago and now they say "not really".

So I put an ammeter in series on the negative side, set it to 250mA, and pegged the needle, obviously way more than the 150mA abscate said he was drawing at the get-go. Does this raise any suspiscons?

Thinking the aux battery might be bad and drawing current through a bad solenoid, I disconnected that battery (and pulled all three fuses under the driver seat), but saw no change in draw.

So I'd like to start pulling fuses, but you'd have to be a contortionist to access the fuses under the dash on the driver side. The manual says to just unscrew something and pull down the access panel, but there is no such screw that I can find. Is there anything I am missing?

Also, there appear to be 3 fuses in a little box directly in front of the main battery. They look different than the other fuses so I am not 100% sure about trying to pull them. Is any one able to ID them for me?

Finally, my dad thought there were fuses in back somewhere, but I found nothing.

Any insight anybody has would be greatly appreciated. Happy new year!

[markcm2]

Does the key happen to be in the ignition? If it is, the vehicle is still in Accessory mode until you remove the key and will power the radio or any other ACC loads.

The dome lights have killed my battery more than once.

Not a likely source in your case but I've had an OBDII scanner that I left plugged in and it's wifi so it killed my battery.

Also, I believe the dash cigarette plug is always active, is anything plugged into that?

[Abscate]

250 mA is way too much, the good news is you have found you battery problem!

The fuses over the battery are huge buss fuses for things like power windows, ignore those for now.

T4s door switches are a trouble spot, the switch stops opening which can leave interior lights on. There a couple of fuses under the driver seat if you have the Weekender model , too. Try Pulling those while watching the ammeter

I’ll try looking up fuse box procedure, disconnect that negative terminal first.

If smog is coming up be aware that you need to drive it for 50-100 miles anytime the battery has been disconnected or gotten low to reset smog monitors, or else you won’t pass.
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[youngster64]

Any update on this post? I'm experiencing some sort of parasitic drain on my 2000 EVC. I disconnected my battery and for some reason I'm seeing continuity between positive and negative battery cables. I'm wondering if you folks have seen this before.

[Abscate]

That’s a meaningless measurement

Get an ammeter in series between the removed negative battery cable and the negative battery post and \report that

It needs to be under <50mA
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