When do you need a battery tender?

[Dannyvandelft]

You can hook up in the trunk just fine. Mine has been for 3 years. Just make sure you put the negative on a grounded stud, not the negative on the battery. That way it doesn't bypass the car itself. Super easy. The CTEK comes with a quick disconnect that peaks out from under the trunk cover, so you never have to remove it. No messing under the hood, no loose wires, nice and clean.

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[Supra_UK_]

CTEK MXS 5.0 - buy it once, and never look back.

I only drive mine once every 2 to 3 weeks, for about 50-100 miles at a time (it's a garage queen/occasional weekend toy only).

So here's the deal, it will be totally fine for 2 weeks un-tendered really, but factors will reduce battery, i.e.:

- Not ensuring the car is locked and totally off.
- Opening/closing the car frequently (while stored).
- Having all the Welcome/Guide me home settings ON i.e. door handle leds, head/rear lights turning on and staying when key is in proximity/after locking - these settings look cool, but will drain battery life faster.
- A good investment is a faraday pouch that will prevent the key from being detected and activating electronic systems.
- Disable tilt alarm sensor. (Press lock button, then press lock button again shortly after, within 10 seconds --> the red flashing light on the interior central mirror will flash solid red for 2 seconds, indicating successful deactivation) <-- this is explained very poorly in the user manual.

- In winter when it's very cold, it is likely to run down faster, so reduce any timing windows proportionally.

What I do for peace of mind is I charge it up overnight once per week, so I know it's always fully charged before I go for a spin, I just fully charge, add a note on my calendar of when the battery was last at 100%, then unplug everything and put it away, as I don't like all the cables in the garage and the hood not shut fully.

I never had any issue whatsoever - but I personally would advise against using the battery directly in the boot UNLESS it's very long term storage i.e. +3 months

As everyone else said, you must click CAR+AGM setting, with a good CTEK you only have to press this once, literally: I pressed it one year ago when I bought it, and every time I plug it in ever since, it remembers the setting.

The CTEK is extremely clever and safe, it is designed not to over charge or damage the battery.

Other 2 things:
- You must ensure you unlatch the hood/bonnet, before you Lock the car, then lock the car with tbe hood up, and only then attach the tender clips. (The red interior light might flash fast, ignore it.).
Once I forgot to lock it, and when attaching the red positive, the car made sounds/things were activated, which is not what you want.
If done properly, when attaching the 2 clips, there should be absolutely no sounds/electronics activating and just a passive charge.

Final fun facts:
If you live in a EU area country with an inferior B58 like mine (UK), the battery is actually slightly different and smaller than the proper 6 port B58 with 384 bhp - I compared mine with all the ones I saw on Youtube videos of the US Supra, and confirmed this, I assume it's because it's less powerful?

Any specific questions let me know.

 

[Teleguy11]

I avoid all of this nonsense by driving mine everyday.? I'm a 2021 with 9600 miles and have had no battery issues so far. Living in Central Florida's heat should kill a battery but so far, so good. ??

 

[Stick45]

Maybe a dumb question, as I’m new to all of this, but I thought I remember reading about a small risk of causing a fire with these types of chargers. Is this risk overstated? Any reason to have a concern about causing a fire?

 

[suicidaleggroll]

No risk of a fire unless there’s something very wrong with your charger

 

[puzzled]

Maybe a dumb question, as I’m new to all of this, but I thought I remember reading about a small risk of causing a fire with these types of chargers. Is this risk overstated? Any reason to have a concern about causing a fire?

I have been using Battery Tender JR ($25-30) for decades.. so far no fire. My Supra, STI, Golf-R are currently hooked up to it and has been since day1 while not driven. I believe it’s a safe battery manager. I can’t speak for the other ones.

 

[Buck]

Do you need to remove the caps on the battery for any gas/pressure build up from charging?

 

[Buck]

I have been using Battery Tender JR ($25-30) for decades.. so far no fire. My Supra, STI, Golf-R are currently hooked up to it and has been since day1 while not driven. I believe it’s a safe battery manager. I can’t speak for the other ones.

Thanks

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