School me on battery tenders

GodStang

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Interesting thread. I had planned using a battery tender from November to late March for my Genesis G70, but found out the battery is in the trunk. First car I've ever owned with a battery in the trunk. So running the extension cord became an issue as I didn't have any holes to run the cord through. I really wanted to use the battery tender, which I ended up returning. So now every 3 weeks I remove a portion of the car cover, climb in, start the car, and let it idle for 20 minutes. I vary the revs during that 20 minutes. I changed the oil before storage and added Stabil to the fuel. So far so good.


Battery is in the trunk on my cobra. I just let the cord run out and lightly set the trunk on it. Zero issues.
 

Uncle Meat

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I use a CTEK unit on the C6ZO6 because C6's are notorious for draining their battery when sitting. My CTEK is left connected all the time and only disconnected when I drive the car. It's connected to an extension cord and it sits directly on the concrete.

The pain with battery tenders for some is the hassle of connecting the charging leads. I went with the cigarette lighter option which works well for me. Since my car is garaged I just crack the window a quarter inch and plug it into the cigarette lighter utilizing one of these adapters.

CTEK.jpg


If you want to get really fancy there's a magnetic option many of the Vette owners use. You can install this in your grill or some other hidden location and then the connection is magnetic. You can even back out of the garage without disconnecting it. It will just pull apart on it's own. Then when you get back you just reconnect to start charging again.

CTEK.jpg


U.M.
 

72MachOne99GT

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Just so I’m reading this correctly, this ctek adaptor allows me to plug the charger into the wall and then simply run the adaptor to the cigarette/12vDC plug, and it maintains the battery through that circuit?

Sounds like witchcraft to me if so.

Also sounds easier than taking my battery out and hooking it to a charger in the corner (I have kids than run wild in the garage and don’t want them tripping over the charger/wires, thats why I pull the battery and charge it elsewhere)
 

BLOWN9646

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Battery Tender Jr here as well. Most important part is if leaving battery connected in car - make sure to clamp postive battery post, & negative to ground (NOT to the negative battery post), then plug tender into outlet
 

Klaus

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Battery Tender Jr here as well. Most important part is if leaving battery connected in car - make sure to clamp postive battery post, & negative to ground (NOT to the negative battery post), then plug tender into outlet

Why not to ground to battery terminal?
 

Uncle Meat

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Just so I’m reading this correctly, this ctek adaptor allows me to plug the charger into the wall and then simply run the adaptor to the cigarette/12vDC plug, and it maintains the battery through that circuit?

Sounds like witchcraft to me if so.
Been trickle charging through my cigarette lighter socket for almost 8 years now. Works like a charm. With the lighter removed the socket is a direct +/- connection right to the battery via the vehicle's wiring harness. Most automotive cigarette lighter receptacles use a 15-Amp fuse and draw up to 180 watts. Circuit is capable of handling a trickle charge no problem.

U.M.
 
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72MachOne99GT

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Been trickle charging through my cigarette lighter socket for almost 8 years now. Works like a charm. With the lighter removed the socket is a direct +/- connection right to the battery via the vehicle's wiring harness. Most automotive cigarette lighter receptacles use a 15-Amp fuse and draw up to 180 watts. Circuit is capable of handling a trickle charge no problem.

U.M.

amazing

Looks like I have something else to put on my middle of summer Christmas list.
 

tones_RS3

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amazing
Looks like I have something else to put on my middle of summer Christmas list.
Looks like you own a '13/'14 Mustang???
If so, that 12V outlet on your dash should be a hot output. Super easy to just plug into with the CTEK and you can put the window up on the cord. Worked great for me with my last car. Did this for 6 years.
 

zak88lx

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Interesting thread. I had planned using a battery tender from November to late March for my Genesis G70, but found out the battery is in the trunk. First car I've ever owned with a battery in the trunk. So running the extension cord became an issue as I didn't have any holes to run the cord through. I really wanted to use the battery tender, which I ended up returning. So now every 3 weeks I remove a portion of the car cover, climb in, start the car, and let it idle for 20 minutes. I vary the revs during that 20 minutes. I changed the oil before storage and added Stabil to the fuel. So far so good.

Bob - Are you sure your car doesn't have front posts under the hood for charging the battery?
My wife's 135i also has the battery in trunk, but we have the battery tender hooked up to the front posts under the hood and it charges fine.

bobpositive.png

bobnegative.png
 
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GNBRETT

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How much is that little tent there? Is it heated?

No worries. I have used Battery Tenders since the 90's and most recently on the 2014 GT500. I leave them plugged in from November To April. Its a trickle charger. If you unplug the battery it will go dead if you are storing for months and not starting. I always used the alligator clips and never had any issues. I have two of them. Make sure your electric outlet is in good shape and if not put a new GFI in.

View attachment 1618566
 

04MysticCobra

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^^^That is called an AirChamber- controlled environment technology. While it is not heated it has 2 small fans in front that circulate the air many times an hour to keep any moisture from gathering. The fans running all year long would only cost $10. When I use it was running about 5 months a year. Problem with my area is that the winter days can be very humid and moist. When I had crappy garage doors and no storage units my cars would get wet underneath and the wheels from those moist days in the winter. Put in insulated Clopay garage doors with the Air Chamber and Armor garage tile on the floor and all those problems were resolved. I had a CarJacket and Car Bubble in the past which were okay but not like this unit. Bought it about 7 years ago and it was $625. Probably more now. The Car Bubble is around $300 but I needed something that I can drive right into.
 

nxhappy

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you don't HAVE to leave it plugged in 24/7. If you want to save electricity you can leave plugged in 1-2 weeks out of the month. Just like a cell phone, too much charging can lessen the battery life. If it's 13 volts, no need to charge it, even at trickle.
 

olympic

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Battery maintainers are automatic. When the battery voltage drops to a certain point due to losses through the electrical system, the maintainer turns on and tops up the battery. So you're not wasting any electricity by leaving it plugged in all the time. Turning it on and off manually is just asking for problems because eventually you're going to forget and have a dead (and possibly ruined) battery. Both my Cobra and my truck will drain the battery dead within 2 weeks if I don't drive them so I leave them plugged in whenever possible. Both vehicles show very small parasitic power draw so I've never been able to figure out the cause.
 

Klaus

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Because hydrogen gas:

View attachment 1618818

Rule of thumb - never confine a battery, keep sparks away.

I understand the issue of hydrogen gas but do not understand how not connecting tender to battery ground solves for this. If this was the issue why have a battery terminal at all?

Am I missing something?
 

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