Charging batt w/ trickle charger in Cold Weather / also brake light bulbs

[nashvegas]

How do I connect trickle charger to my LR3 HSE (2005)? Just hook it up to the battery +/- terminals, or do I need to disconnect battery first? Looking for guideance / best practices so I dont fry anything in the electronics. I had a 90's Saab 9000 Turbo on which you had to disconnect the batt from the car or you could fry/screw up the TCS system (hence asking first!)

Here's why:

Few weeks ago in a snowstorm here in Nashville, 26 degrees out, I was idling on a city street at a stoplight, all of a sudden got the trans fault / slow down, HDC unavail, suspension lowering, brake warning lights. Hmphf. Turned off truck, started right up, faults cleared. Next day found out that one of my brake light bulbs (passenger rear upper) was out. I was relieved b/c I'd read about the brake light bulbs blowing being root cause of these "cascading faults" on 2005 LR3s. I immediately replaced both driver / pass side upper brake light bulbs (with the 4 dollar ones from the LR dealer so as not to cause issues). Drove for awhile, no issues.

Then today... driving to work.. got same sequence of faults. Noticed truck sounded a little "sluggish" when cranking this AM. About 20 mins later on a city street, truck lowered to below access mode, bump stops I'm guessing. Trans fault, HDC unavail, etc. The car was super icy (parked outside). I'm guessing battery even tho it's only about 9 mos old (it was replaced when I bought the truck CPO June of last year).

 

[e24kgold]

I would test the battery first to see if its weak. Disconnect it if you decide to charge it. I would just replace it. I just did mine with the Interstate MTP-8 (i think) for about $200

 

[drivesafe]

Hi nashvegas, if you want to hook up a battery charger of any type, turn the ignition off remove the key, apply your parking brake and then wait till the parking brake light goes out ( anything up to 3 minutes ).

While your waiting for the light to go out, take the cover off you cranking battery compartment.

Once the light is out you can then connect the battery charger to your battery.

It is recommended that you connect the battery chargers positive lead to the battery’s positive terminal and the negative lead to a bolt or earth point somewhere else.

This is to avoid the possibility of a spark igniting any hydrogen gas that may have accumulated around the battery.

You do not need to disconnect the battery to charge it.

By the way, if you still have the same problems after charging the battery, you might try having the battery load tested. This will tell you instantly as to the condition of your battery.

 

[Disco Mike]

Test the battery first, should have between 13.6 and 14.4 volts.
Sounds like your battery is on it's way out.

 

[nashvegas]

Thanks all but a ? about battery voltage

I tested battery, with car off, connected to my battery charger machine, I get 12.9, 13.0, 13.1 volts, right around there.

Mike, are the #'s (13.6-14.4) you are talking about with car on and idling? They are, right?

I sound like an old man but I know how this works on older cars, but new cars with power management like these LR3s totally baffle me.

 

[drivesafe]

You need to test the battery with the motor off and preferably at least 12 hours after the motor was last run.

With Calcium/Calcium batteries used in D3s, measuring after 12 hours, any voltage above 12.5 is a near fully charged battery and anything above 12.2v will indicate the battery is holding a charge but is not fully charged.

Try fully charging your battery with your battery charger and again, once fully charged, leave the battery for 12 hour and measure the voltage again.

As posted earlier, the simplest alternative is to go to a battery centre and have the battery load tested.

NOTE a fully charged battery will give a reading of 12.6.5v or higher, but anything above 12.5v is an indication that the battery is charged.