Battery dead -- from high speed phone charger??

Hi all, I'm relating a recent experience in case anyone has input or it's a useful FYI:

About a month ago I replaced the small low-power phone charger I'd had in my 12V socket for a year with no problems. The new unit was a high speed charger from Anker. It's a well reviewed charger from a known good company, and has both a USB A and USB C port capable of putting out about 20 watts each. My truck then sat unused for a few days and when I went to start it -- nothing. Dead as a doornail.

Toyota Roadside Assistance jumped it and it's been fine ever since, including after some days of no use. But after the battery died I removed the phone charger out of suspicion it was the culprit. And I haven't tried to use it since.

It seems strange to me that a charger would pull enough power (when not charging a phone!) that it would drain a one-year-old car battery in a few days. What do y'all think? Is it the charger or should I be worried about something else?

PS -- truck has 10,000 miles on it and there have never been any other issues of this kind.

Thanks all!

 

Stange, I thought the USB plugs/12v socket weren't powered when the vehicle is off, but im far from an electrical engineer.

 

Certainly possible it could be a constant drain. Maybe you inadvertently created a ground so the battery constantly discharges...? How did you do the wiring? Did you simply replace the socket with Anker's high capacity one, and nothing else at all? Did you wire it by itself with a dedicated fuse tied to an ignition-based source so its only on when the car is on? Did you tie it directly to the battery so there is constant power?

 

I've never had issues with Anker chargers plugged into the power outlets. You can use a meter to find the power draw if there is one. The outlets are off when the key is off though.

 

Thanks for these thoughts. All I did was plug the new phone charger into the 12 volt socket (aka cigarette lighter socket). No wiring or anything else. I had a low power charger in that socket for a year with no issues. The dead battery occurred after I replaced it with the new charger. Related? IDK. But certainly an interesting coincidence.

 

Thanks. It certainly is weird…

 

Pretty sure the 12v socket is ignition powered, therefore it cuts the power to it when the vehicle accessory isn't on.

That couldn't be the issue if you didn't change any factory wiring.

However, you likely do have a draw somewhere.

Define:
1. A few days - how many?
2. Temperature outside? Cold kills batteries faster.
3. Any other mods, wiring, electrical at all?

 

If you just plugged in the Anker charger into the cigarette lighter there should be no way for it to drain. Its not even transformer losses or something, its just cigarette lighter 12VDC to USB A or C 12VDC...
So far sounding like pure coincidence. No other changes or mods during that same time frame?

 

Thanks. No mods at all except OEM led fogs installed by the dealer when new. Weather was moderate. I’d say three days no use. But, again, it’s sat under these same conditions several time with no problem. The only change I know of is the charger. It may not be related, but if not then why would this happen all of a sudden?

PS I did see a Toyota TSB on dead batteries that advised service departments to check for phone chargers in cases of unexplained battery drain. So they seem to think such chargers can cause this?

 

Most likely an excuse, here's why.

12v "starter" battery with 14.4 volts at 75AH capacity and is lead acid, so 50% of it is useable. That formula looks like:
12v * (75/2 = 37.5) = 450WH.

A 5V usb charger pulling 20watts would look like (without inverter losses):
5v * 4amps = 20W

450WH / 20W = 22.5 hours of constant draw a full draw.

Most 20W chargers rate 20W for the entire charger, so if it has 2 ports, both are 10W, and it's limited by most phones, which are 5W or 10W, so let's say 10W.

That's 20w/2 outlets = 10W and then 22.5hours now becomes 45 hours of constant draw, or approximately 2 days.

But that's a full draw, when the phone is charged, it stops pulling full current. I'd say it might take a solid 7 - 10 days to draw down a phone like this with normal use.

All of that assumes the charger is even on.

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You got a bad battery I'd guess. Once you deeply discharge a lead acid it permanently sulfates, it will never again be it's full capacity. Most starter batteries are really not designed to discharge past the top 20%, and I was using 50% in this example.

More than likely the battery was bad front he beginning, was run down, then charged up and sold in the new vehicle. They probably need to replace the battery.

If that's not it, you got a parasitc draw somewhere and they can be HARD to find. Let's hope it's the battery.

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TLDR: Highly unlikely a phone could do this in 3 days.

 

I’ve had one or those in for years.