Battery Tender Jr. connection question
 

I got a Battery Tender Jr to keep my Boxster charged. It comes with spring clips and also ring terminal connectors. Both sets of connectors then connect to the A/C end of things, which goes to the wall. Seems pretty straightforward.

My question is about using the ring terminals. The directions don't say. If I choose to use those, do I just connect them to the battery terminals, and leave them there all the time? I'd be able to replace the battery cover, and close the frunk lid to shut off the courtesy light. I'd disconnect those leads from the A/C portion when I want to drive the car, leaving the other ends on the battery terminals. Right? Using the spring clips makes it a hassle to put on and off all the time.

Am I missing something, or is that the right way to use the ring terminals?

Dave

That's the way to do it. Use the ring terminals and leave them connected.

What you should be using is the cigarette lighter adaptor, the car was built to connect a battery maintainer that way:

https://i5.walmartimages.com/asr/4cc...0&odnBg=FFFFFF

+1 On Cigarette Lighter Battery Maintainer
 

Been using mine like this for 8 years (same battery). Works great and is the easiest thing in the world to hook up.

I use the clips and run them out between the hood and the windshield for winter storage. My Ktm that doesn't see the same amount of use in the summer and has slightly less easy battery access has the hardwired set.

Just check to make sure cigarette lighter is connected with the ignition off, in some markets (Australia is one) there is no connection when the ignition is off

I have connected mine to the battery direct, just don't forget to disconnect before driving away! Don't ask how I know!

Cheers

If you use the cigarette lighter connection, where do you run the wire through, since the windows will be up and the top secured?

The bottom of the drivers door has a recess in both the door and the weather stripping just below the review mirror, it is there to run the cable into the car so the car can then be locked. Simple, but effective factory design.

Actually....
 

...there are TWO cutouts on BOTH doors. One at the bottom, and another at the "corner" of the door below the door jam.

Use the cigarette lighter and the cutouts in the doors. Works like a champ.

I use this one, very happy: CTEK Multi US 7002 - CTEK Battery ChargersCTEK Battery Chargers

Thanks, guys. I appreciate the answers. Mine didn't come with a cigarette lighter connector. I can see why that would be a nice option.

Dave

So you use the cigarette lighter to connect the battery tender to the battery you are maintaining. Drawing energy from the battery to inject energy into the battery. How does that work? Buck and boost internals in the tender?

I had wondered the same thing.... but for the last 10 years I have used a Battery Tendered plugged into the cigarette lighter without issue. Perhaps the cigarette lighter has to handle a heavy load to work thus can handle a the Battery Tender.

Brilliant. That's a smart design!

Ummmm. No. The battery tender gets plugged into the lighter socket at one end and into a 120 volt outlet at the other end. The tender takes 120 Volts, converts to 12 volts and feeds it to the battery via the lighter socket. No magic here.

That said, I have my tender attached directly to the battery and I simply disconnect it at the cowl. Just like Keith Newby.

[QUOTE=morgal48;532267]So you use the cigarette lighter to connect the battery tender to the battery you are maintaining. Drawing energy from the battery to inject energy into the battery. How does that work? Buck and boost internals in the tender?[/QU

The battery tender is plugged into an electrical outlet, and is connected to the cigarette lighter for charging. You beat me to it,lol. I use the clips but yes the ring terminals would be a better choice, I used mine on a motorcycle I sold. I have a battery cut off switch installed on the battery, so in the winter months I disconnect the battery, while it's charging.

Is there any issue to leaving the battery connected and running the charger into the cig lighter (otherwise you'll need to recode etc.)? I believe the CTEK 7002 will not overcharge the battery (I have a Porsche branded one that I understand WILL overcharge the battery).

This is what I use from Princess Auto.

https://www.princessauto.com/en/detail/spf1-automatic-battery-charger-extender/A-p8487332e

I picked up 2 using one on my Boxster full time all winter and during driving season if the car sits for any length of time and one on my Fusion since it isn't driven as much in the winter. These will not overcharge and have proven very reliable.

I got them both when Princess had them on sale for about $45.00 CDN I believe a couple of years ago.

Depends upon the quality of the maintainer. Good units, like the Ctek, can be left plugged in indefinitely, other lesser units may not actually be maintainers, but are "trickel chargers", which never shut off and can cook the battery over time.

Thanks! That never occurred to me. I use ring terminals on all mine. Old people linear thinking.

You're welcome! I need to buy a set of ring terminals, they're inexpensive. Yeah, I'm an old person too.:cheers:

Anybody know how long a normal charging session for a Battery Tender Jr generally takes? Battery Tender instructions say a fully-discharged battery will take approximately 16 hours to recharge. For those of you who have used one, is this a normal number, or can it take longer?

I put the ring terminals on my Boxster battery yesterday. The tender has a single status light with four modes: Red flashing indicates a battery with too low a voltage, or ring terminals not properly connected. Solid red indicates normal connection, and battery is charging. Blinking green indicates more than 80% charged, and can be disconnected. Solid green is fully charged, and the tender has shifted to maintenance mode.

When I first connected the tender, the status light went to solid red. I expected that, and knew that things would be charging for awhile. But it's now been more than 16 hours, with no change. I don't know how to gauge whether my battery is just slow, or if there is a problem. Everything seems normal, but... ?

Yeah, yeah, I know: First-world problem. ;)

Dave

I would not worry unless it takes longer than a couple of days.

Update: When I went out to the garage to head for work this morning, the Battery Tender status light was solid green. So it finished charging sometime overnight. That would mean it took ~36 hours to charge. No telling how low the battery was before I plugged it in. Battery is not quite four years old, so should have a fair amount of life left in it.

Dave

Terrific! If the battery is a bit run down it does take a long time for the tender to bring it up to full charge.

Yep. Now that I have a baseline to charging it, I can keep an eye on it. My concern was that I had somehow connected it wrong, or that the ring terminals I put on the battery weren't right, or something. When the only sign something is working is the color or a light, it's a bit strange till things sort themselves out.

Dave

In Florida we start looking for replacements about then.
Any time after 4 years or so you stand a chance of finding out the hard way.
The heat just bakes the life out of batteries here.

(BTW.....I use a Tender Jr on both my Boxster and Harley and it does help prolong the battery life somewhat.
But they can also give you a false sense of security.
When the battery fails, you don't get a bunch of subtle warnings......they just go)

Good info to know. Thanks! I don't know whether we have an average lifespan of batteries here. Weather in my area is moderate at best, rarely too hot or cold. Just lots of rain, which keeps the Boxster in the garage... :)

Dave