1995 850GLT Battery Terminal-Ground?

viper69 · Post by **viper69** » 31 Aug 2014, 16:58

I need to charge my battery with my Battery Tender Plus. I know which terminal posts are positive and negative. However, I can't really tell which one is the ground. I know modern cars are typically grounded by the negative terminal. However in my car, I can't seem to find a ground wire connected to the car chassis.

How would I determine this? I'm not the most electrically literate person.

Post by **Ozark Lee** » 31 Aug 2014, 17:31

Negative is common which in automotive parlance is ground. There is no actual earth ground on a car but the negative battery cable ties directly to the chassis.

...Lee

Post by **polskamafia mjl** » 31 Aug 2014, 17:34

This past winter when I had a dying battery I simply hooked the positive cable on my charger to the positive terminal on the battery and the negative cable on the charger to the negative terminal on the battery.

Post by **abscate** » 31 Aug 2014, 19:23

viper69 wrote:I need to charge my battery with my Battery Tender Plus. I know which terminal posts are positive and negative. However, I can't really tell which one is the ground. I know modern cars are typically grounded by the negative terminal. However in my car, I can't seem to find a ground wire connected to the car chassis.

How would I determine this? I'm not the most electrically literate person.

You would disconnect both battery cables and measure resistance to ground using a volt ohm meter on the ohm scale. The one grounded will read 0 ohms.

Almost all cars except for some old British cars are negative ground nowadays. By "almost all" I meam 99.9%

On Volvo the negative cable dives under the battery and grounds just forward of the battery

viper69 · Post by **viper69** » 31 Aug 2014, 19:47

Thank you all for the input, much appreciated. The location being underneath to some extent would explain why I can't find it. In my Nissan it's really obvious.

I read the simple instructions of the Battery Tender Plus. In the instructions it reads "connect the negative (black) alligator clip to the vehicle chassis"

Though on their website they have a diagram of the negative clip going the negative post.

Does it really matter?? I'm sure it doesn't based on what Lee wrote, but just curious as to the discrepancy.

Post by **scot850** » 31 Aug 2014, 19:54

I never charge my battery with it connected. I remove the negative lead at least (the closest one to the LH inner fender. Most batteries I had have some form of '+' or '-" sign molded into them somewhere near each battery post.

Only time I don't disconnect my battery to charge is when using a trickle charger. Here, I treat it like I was boosting the car, and connect Live (RED) to the charger, and negative to the earth lead bolt at the back of the block near/on the rear upper torque mount. This way you are less likely to zap electronics.

Neil.

Post by **abscate** » 02 Sep 2014, 08:55

viper69 wrote:Thank you all for the input, much appreciated. The location being underneath to some extent would explain why I can't find it. In my Nissan it's really obvious.

I read the simple instructions of the Battery Tender Plus. In the instructions it reads "connect the negative (black) alligator clip to the vehicle chassis"

Though on their website they have a diagram of the negative clip going the negative post.

Does it really matter, I'm sure it doesn't based on what Lee wrote, but just curious as to the discrepancy.

I read that the Battery Tender Plus is a 1.25 Amp charger That makes is about a 15 Watt power output. To charge a dead battery will take about one week with this charger. Nothing wrong with that use, just be aware.

Interesting claim on the website....

"Battery Tender® at 1.25 amps will charge as fast or faster than any 3 amp charger available."

viper69 · Post by **viper69** » 02 Sep 2014, 09:59

What about my question in my last post? haha

It's not dead, just needs a little "topping off".

Post by **scot850** » 02 Sep 2014, 11:57

If you mean where to place the negative lead, check my post above. I never connect to the earth side of the battery direct, unless the battery is disconnected. I connect my earth cable/negative to the bolt holding the earth cable at the back of the cylinder head that runs to the firewall near the top torque mount.

As abscate says, this is not a method to charge a flat battery, but as you state it is just to 'top-up' for which it is great.

Neil.

viper69 · Post by **viper69** » 02 Sep 2014, 12:33

scot850 wrote:If you mean where to place the negative lead, check my post above. I never connect to the earth side of the battery direct, unless the battery is disconnected. I connect my earth cable/negative to the bolt holding the earth cable at the back of the cylinder head that runs to the firewall near the top torque mount.

As abscate says, this is not a method to charge a flat battery, but as you state it is just to 'top-up' for which it is great.

Neil.

Thanks. So because I'm not electrically inclined, considering my negative terminal is the ground, why would connecting the negative wire of my charger to another part of the car minimize zapping electronics? Is it soley because it wouldn't be connected to the battery, and thus not completing a circuit? Just curious really. I 'm not suggesting you are wrong at all, please don't take my questioning that way.

2 more Questions:
I'm charging the battery with the car's terminals attached to the battery's terminal posts. I attached the negative (black) cable to the "arm" that supports the hood. The metal seems thick enough.

1. Can I stop the charging process and start it tomorrow or is it better for the battery to do a charge in one continuous charge/connection?

I ask because the unit is outside and my neighborhood while relatively safe, who knows. Also, I feel a bit uncomfortable w/the hood up and electricity running from the garage to the battery while I'm sleeping, the old "what if something happens" mindset.