Where do you connect the negative for the battery tender?
 

Oops, I have been connecting it to the negative terminal on the battery but apparently that's not right.
Where does everyone connect theirs?

This is the connector I have.
https://cimg6.ibsrv.net/gimg/rennlis...23420aa825.jpg

Car is a 87, 3.2

it's fine - do it

Where did you hear it shouldn't be connected to the battery terminal? I've never heard of anyone connecting it anywhere else.

it has to be a garbled stmt. from someone who confused a high amp battery to battery connection (which might arc & cause a BANG) with a low current output tender...

That's what the manual for the CTEK charger says.
FOLLOW THESE STEPS WHEN BATTERY IS INSTALLED IN VEHICLE. A SPARK NEAR BATTERY MAY CAUSE BATTERY EXPLOSION.
For Negative-grounded vehicle, connect POSITIVE (RED) clip from battery charger to POSITIVE (POS, P, +) ungrounded post of battery. Connect NEGATIVE (BLACK) clip to vehicle chassis or engine block away from battery. Do not connect clip to carbure- tor, fuel lines, or sheet-metal body parts. Connect to a heavy gage metal part of the frame or engine block

https://cdn.shopify.com/s/files/1/01...82651556756717

I am fully aware of jump starting a car and never connecting the negative to the battery.

well, it won't hurt

IIRC, C-TEK is Swedish, so expect super careful, high safety attitude from them

I'm no DC electrical expert, but for the last 14 years I've connected my tender leads directly to + - terminals on 2 boats, 4 motorcycles, 2 deep cycle marine batts during winter storage, a golf cart aux 12v battery, and 4 cars. All have lasted years longer than average/conventionally held. :shrug

I didn't read the CTEK manual, but does it tell you to connect the leads before plugging it into the wall outlet? I only use a Battery Tender Jr., and always connect to the battery before plugging it in. Doing it that way prevents any possibility of a spark when connecting the negative lead.

It does.
I actually leave the little connector on the battery and once I get home, I just pop the hood open and connect the little short dongle to the long cable coming from the charger.

I guess some of this info that's spread online must be related to the procedure for jump starting a car and not trickle charging using a battery tender. I will carry on doing what I am doing.

On the 991, there's an easy way to connect the negative, clearly labeled (-).
https://cimg1.ibsrv.net/gimg/rennlis...2570c42f6f.jpg

yeh, don't worry about it


now, rubber fuel hoses, OTOH...


https://cimg8.ibsrv.net/gimg/rennlis...6efa177b1f.jpg

I don't think it's that affects the battery more than the safety aspect of it.

Some people think, like when connecting a battery to jump a car, there can be a spark (and thus an explosion resulting from vented hydrogen gas) if you connect the clamp to the negative terminal... and instead it should be grounded further away from the battery.
But now that I think about it, there shouldn't be a spark if you plug the clamps first, and then connect the charge to the wall.

As I said above. Impossible to create a spark if there's no connection to another power source.

You can ground on the chasis or the battery

after all the ground on the battery connects to the chassis

I've been connecting battery chargers & maintainers/tenders directly to the battery terminals without any issues whatsoever since 1960. :)

Same applies to jump starting cars in need of a little "boost".

Now,....late-model cars (2000-newer) are something else entirely and caution is strongly advised in those situations.

Well to make it easier and safer I installed the other connector that came with the CTEK. It was a pain in the butt trying to loosen the nut on the terminals since it's a tight space.

https://cimg0.ibsrv.net/gimg/rennlis...626461197c.jpg