Nearly dead battery

[samsontdog]

I have a battery cutoff switch to my TT battery. It was discounted from
the TT. I switched it on and went inside and the battery was nearly dead. It was fully charged when it was switched off. What would cause it to go dead in two weeks? 20011 Gulf Stream TT.

[maillemaker]

Every wire should be fused to reduce the possibility of a fire hazard.

Indeed every wire should be fused, but not every fused wire is fused at the fuse box. Some have inline fuses.

I agree that the best place to check for parasitic drain is at the battery, between the negative battery terminal and the chassis ground.

However, once you determine you have one, then you have to start poking around in individual circuits, like at the fuse box, to find it.

[ken_white]

Bobbo wrote:
How do you know you don't miss a wire? With the first guy's suggestion, you CAN'T miss a wire.

Every wire should be fused to reduce the possibility of a fire hazard.

However, I guess there is a possibility that "someone" installed something improperly.

My method identifies each branch that contains parasitic load(s).

[Bobbo]

How do you know you don't miss a wire? With the first guy's suggestion, you CAN'T miss a wire.

[ken_white]

Bobbo wrote:
But that assumes that the load is going through the fuse block. Not all do. Some come directly off the battery with their own fuse.

It is true that some fuses have a direct connection outside the fuse panel/block.

I think my test covers those too...

🙂

[Bobbo]

But that assumes that the load is going through the fuse block. Not all do. Some come directly off the battery with their own fuse.

[ken_white]

maillemaker wrote:

Buy a cheap 12 volt test light. The kind without batteries inside.

When reconnecting the tested-good or new battery connect the POSITIVE FIRST. Leave the negative disconnected.

Clip the test light clamp onto the ground wires that lay disconnected from the battery terminal.

Grab the test light and touch the tip to the positive post, the one that remained disconnected.

Does the light light up?

Yes. You have a draw somewhere. Your disconnect switch is bypassed or shorted somewhere. Leave the negative wire disconnected until you get around to fixing what's wrong.

I am confused about this test.

You say to connect the positive terminal (first), and leave the negative disconnected.

Then you say "touch the tip to the positive post, the one that remained disconnected."

But you said to connect the positive terminal.

Can you please explain?

Thanks,

Steve

He meant negative post so the circuit can be completed...

But, this puts the lamp in series with all of the loads so the lamp will be very dim.

A better solution is to pull each DC fuse one at a time, set the meter to read DC current, and connect the meter leads across the empty fuse slot.

this will read the current for that fuse's branch.

[ken_white]

RJsfishin wrote:
The largest load tester that Schumacher sells is 100 amps
http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_x_21280021-P_x_x?cm_mmc=ACQ-_-Goo...

But what would a chincy cheesy company like Schumacher know about battery testers ??

500A

[maillemaker]

Buy a cheap 12 volt test light. The kind without batteries inside.

When reconnecting the tested-good or new battery connect the POSITIVE FIRST. Leave the negative disconnected.

Clip the test light clamp onto the ground wires that lay disconnected from the battery terminal.

Grab the test light and touch the tip to the positive post, the one that remained disconnected.

Does the light light up?

Yes. You have a draw somewhere. Your disconnect switch is bypassed or shorted somewhere. Leave the negative wire disconnected until you get around to fixing what's wrong.

I am confused about this test.

You say to connect the positive terminal (first), and leave the negative disconnected.

Then you say "touch the tip to the positive post, the one that remained disconnected."

But you said to connect the positive terminal.

Can you please explain?

Thanks,

Steve

[RJsfishin]

The largest load tester that Schumacher sells is 100 amps
http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_x_21280021-P_x_x?cm_mmc=ACQ-_-Goo...

But what would a chincy cheesy company like Schumacher know about battery testers ??

[MEXICOWANDERER]

Had a little bet with a distributor. Full-on dinner at Tony Roma's drinks and dessert. His argument was the same as yours. RJ's fishing. "They all have cheesegrater testers".

His incidence of testing OK but having the battery come back bad in 90 days was >30%. Mine was zero 0.0000000%

Auto Meter's 800 ampere tester sold for in excess of FIVE HUNDRED DOLLARS. And Other than Sun's VAT 33 and VAT 40, it was just about the only full BCI loading method of testing batteries correctly. THAT's WHY THEY USE THE CHEESE GRATER LOAD TESTERS. "Better-then-nothing, is not the same as ADEQUATE".

3 VO & Water, King Size order of baby back ribs and coconut chocolate pie coming up!

If you contact the BCI and ask them about the relevance of testing batteries with a cheese grater, you will hear silence, then a chuckle.

This is as silly as saying one of those "Five Floating Balls" hydrometer thingees can substitute for a Francis Freas hydrometer, or a Stewart Warner dash gauge voltmeter will suffice for battery monitoring. Yeah 28 dollars when I purchased 30 of them. Ooooo what a surprise. 12.00 volt power supply, readings from 11.5 to 13 volts. The official reply from Stewart Warner? "Well, they're meant to give an acceptably approximate reading".

Chesse graters. Better than nothing, but not by much.

[Pauljdav]

Also check the breakaway switch for the brakes.

[RJsfishin]

Quote:
Hospitals have cardiac patients on a TREADMILL not sitting in an easy chair. The 100 amp load tester is near useless. Except if you plan on using a 200 amp hour battery. A perfectly bad battery can pull the wool over the eyes of a 100 amp load tester so fast it'd make your head spin
-------------------------------------------------------

Yeah, that's why every auto parts in the US sells them,cuz they are useless.
And they accuse me of snoddish sarcastic remarks !

Maybe try getting out in the real world someday, and forget the books.
I said it before, I may not always know whats right, but I know what works !

[MEXICOWANDERER]

The 100 amp tester is like getting a cardiac stress test...

"OK all the electrodes are connected. Now grab a book and start reading".

Hospitals have cardiac patients on a TREADMILL not sitting in an easy chair. The 100 amp load tester is near useless. Except if you plan on using a 200 amp hour battery. A perfectly bad battery can pull the wool over the eyes of a 100 amp load tester so fast it'd make your head spin.

The BCI developed the 50% of CCA, 9.6 volts minimum after 15 seconds of loading for a reason.

"I want to test drive your car before I buy it. Say to the end of the block?"

The 500-amp load tester is the way to go. Way to go Bobbo.

[Bobbo]

After reading your post, I ordered this.

500 amp load tester