Battery Tender Issue

Silly questions to start off with :

Did you plug into the car first, then into the wall? I have found that if I do it the other way around, battery maintainer does not function properly and the battery voltage may drop.

Also, is the maintainer is still plugged into the car, I believe the car will not turn over at all if so.

 

Indeed, that is what the Cali manual says on page 206.



"The engine cannot be started as long as the battery conditioner is connected to the vehicle socket."



However, you will note the little warning icon in the lower left of page 139 (it's a battery w/ a plug) which indicates ...



"Battery conditioner connected

When the instrument panel is on, it indicates that the battery conditioner is connected (priority level 0)."



And, I can tell you from personal experience that you can indeed drive with the tender plugged into the car port. Thank goodness, in my case, it was all neatly tucked away in the rear boot.



OP - Can you take a pic of your conditioner? I'll post a pic of mine in a sec.

After a drive, when I first plug in tender, the middle light is amber /red. Then, the right light turns green, as you see in pic. The left hand one with the ! has never lit up, & that is a good thing as I'd likely freak out! [emoji6]



BTW, I always plug my tender into the car port, then plug the tender into the wall. Then reverse when I want to drive.

T

 

Looks like you have a defective tender.

T

 

You probably know this already Tom but I think it should still be mentioned as a note of caution here.

If you leave the battery tender connected to the car while the tender is not receiving current from an A/C outlet, the battery tender will drain your car's battery. The direction of the charging current will reverse because the car battery's voltage will be higher than the battery tender's. A lot of people have found this out the hard way.

This is also why your battery charger always charges at a higher voltage than the voltage rating of your battery. Make sure to connect power to the battery tender. From my experience, it does not matter if I power up the battery tender before or after it is attached to the charging port of my car. Therefore to avoid accidental draining of the car battery, my battery tender is always hooked up to power regardless of whether it is connected to my car.

 

Yes, thank you, I got that warning before from an F-chatter who found out the hard way. But, it's good to repeat the message from time to time.

I fully disconnect & unplug & then store the tender in my boot every time. Well, except for that one time I was driving with it connected. [emoji15] Fortunately, the warning pictogram sufficiently freaked me out that I pulled over at the first opportunity and started going through the owner's manual I keep on my iPhone.

T

 

Actually, wouldn't it be handy if the factory would embed a searchable copy of the car manual within the infotainment system? Even better if Siri could look things up for us in the manual. But yeah, FChat is a great resource, isn't it?!

 

With iBooks on my iPhone I can do string searches of a PDF copy of the manual. Sometimes it takes a sec or two to find the right keyword, but it's saved me undue stress on a few occasions. F-Chat is the ultimate reservoir of info on the web! No way I could have made an informed purchase decision without the info I learned from many great contributors...T

 

there is a device known as a diode that allows current to flow in one direction only, any charger / maintainer manufactured in recent history with a circuit board has a diode that prevents any reverse current flow. A quick check with a meter will verify if there is any back flow of current. Should not be an issue

 

Mine has a lot more lights than that.

 

I know about diodes but even if such a circuitry is implemented, it does not infinitely prevent reverse current leakage and I believe the resistance from the diode also draws power. There is what's called "back current drain" that some battery tenders have in their technical specs. Curiously, not all chargers are supplied with complete technical specs.

There have been Fcar owners who reported their batteries were drained because they forgot to attach power source to their chargers. If you leave the thing hooked up over several months without power, depending on the original state of charge of the battery when the charger was first connected, the charger could potentially drain your battery.