quick little battery question here

MysticMac

MysticMac

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Little battery question here... I pulled out the fuse for the map lights and courtesy lights so i can keep my battery hooked up over night so i can see if I actually need a new battery. I put multi meter leads + and - on the + and - battery terminals and it was reading 14.38. Is that too much? Im changing my door lock assembly and need to know if I really need a new battery or not.

2005 LS v6
 
A properly charged battery may well show a bit more than 14 volts. You might find that some of it is 'surface' charge and will go away even when the battery isn't hooked to anything.

KS
 
Can charge a battery doesn't mean it likes loads and recharges.

... try it ...
 
You'll know if, when you put it in, if it'll functions as intended, meaning it gets charged properly by the alternator. Starting the car and/or turning on the rear glass defrost puts a good direct load on the battery.

RigsLS said:
... likes loads and recharges
Click to expand...

when batteries are near done, they tend to be weak with the cranking amps and slow to charge if even fully. (puts a strain on the LS alternator btw, more $$$)

.
 
Last edited:
Oh, thought you were putting in another battery. You're looking for your parasite to not drain. got it.

How about hooking it up to a battery tender when not in use.

Permanently at the posts, connect battery tender and have charge cord closed on trunk plugged in.

Canadian Tire sells those handy compact battery tenders.

Battery Tender Junior, 0.75A Maintainer | Canadian Tire

.
 
yeah im going to buy a new battery regardless but I want to know if I can still use this battery for the time being and have no issues down the road. I cant really afford to buy the battery I really want right now (amg) but if I really need to I will just buy the OEM Motorcraft.
 
MysticMac said:
yeah im going to buy a new battery regardless but I want to know if I can still use this battery for the time being and have no issues down the road. I cant really afford to buy the battery I really want right now (amg) but if I really need to I will just buy the OEM Motorcraft.
Click to expand...

Why guess? Have it load tested. Some auto stores will do that for free, and some even do it correctly.
 
joegr said:
Why guess? Have it load tested. Some auto stores will do that for free, and some even do it correctly.
Click to expand...
No places around my place offer free loadtests lol.. When I go to autozone in bellingham this weekend ill bring the car but if its over 14.7 for more than a few minutes without dropping voltage than im not going to keep using it.
 
MysticMac said:
...but if its over 14.7 for more than a few minutes without dropping voltage than im not going to keep using it.
Click to expand...

You do realize that high voltage is a charging system problem, and not a battery problem (other than it does damage the battery)? If the DC voltage is going over 14.8 (14.5 would be a more normal maximum), then you have a problem with the voltage regulator, or the wiring to it. If this is the case, then changing the battery may hold it down some for a short while, till the new battery is cooked too.

I am confused, what is your actual problem here? You mention a parasitic drain and high voltage. Those are two separate and unrelated problems. The voltage regulator on my 325i failed. It was putting out upwards of 18V and causing all sorts of problems. To drive the car to where I could change out the alternator, I disconnected the power wire to the alternator and just ran off the battery for the ten miles or so that I needed to go.
 
i have a bad door lock assembly i pulled the fuse out so the interior and courtesy light doesnt kill my battery over night... I wanted to see what my battery was reading and it read 14.38 ..where is the voltage regulator located?
 
The voltage regulator is inside the alternator. 14.4 was with the engine running, correct? If not, you simply have a bad meter.
Pulling the fuse for the lights will greatly reduce the drain, but won't eliminate it. You'll still have the problem that the car won't sleep. If you park in a garage, you could probably just leave that door open, and then the car would sleep (no need to pull any fuses).
 
joegr said:
The voltage regulator is inside the alternator. 14.4 was with the engine running, correct? If not, you simply have a bad meter.
Pulling the fuse for the lights will greatly reduce the drain, but won't eliminate it. You'll still have the problem that the car won't sleep. If you park in a garage, you could probably just leave that door open, and then the car would sleep (no need to pull any fuses).
Click to expand...


I had the car running for about 5-10 minutes and at the 5 minute mark i tested the battery and it read 14.38 so is that normal joegr? and i used the search button and found another member asking about the charging and your replies are useful
 
Yes, 14.4 is perfectly normal with the engine running. Did you see closer to 15 at some point? If not, why the concern about over-voltage?

Note that checking battery voltage will the engine is running tells you something about the charging system, but it really tells you nothing about the battery.

Generally speaking....

Engine not running, no load on battery:
<= 10 volts - battery is fully discharged and has probably been damaged.
< 12.6 volts - battery is discharged
12.6 to 12.9 volts - battery is fully charged
> 12.9 volts - surface charge from very recent charging, give it several minutes and check again.

Engine running:
13.8 to 14.8 volts - normal operation. (will usually be 14.2 to 14.5 volts)
< 13.8 - Charging system is overloaded of defective (or engine idle is too low)
< 12.9 - Battery is discharging.
> 14.8 - Battery is being over charged (will vent, will be damaged)
> 16.0 - Electronics and bulbs may be damaged
 
Ok I was confused when I read 14.38 because Im not familiar with the decimal point on a multimeter and how to properly describe what im reading when explaining. 14.38 is 14.4 (14.40) ?
 
Key turned to the run position.
DDM fault
Remote battery dead
Remote transmitter fault
Remote not authorized (not programmed in)
Rolling code way out of sync
Strong RF interference
 
It would have to be one that could scan for Ford specific codes, but even then, it is unlikely to pick anything for this.
 
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