2 batteries 13.3v

[PuZo 10+ year member]

I just moved my old yellowtop the to trunk and put in a new starting battery.

When the car starts it shows 14v but after a while it drops to 13.3v. Would this mean my yellowtop is drained? I've had it for probably a good 5 years. I had a xs power d675 before but I figured the yellowtop would be better even though it is older.

This is with no load other than normal car functions.

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[vibe]

Mine does too. When your alt heats up it tends to start losing power. Mine starts at 14.4 n when hott charges at 13.9ish. I know thats one reason why your voltage drops.

 

[mylows10 5,000+ posts]

Disconnect the batteries from each other and check all of them individually. Sounds like ones bad

 

[PuZo 10+ year member]

Well considering one is new it's probably the yellowtop?

 

[SounDrive Pro Seller]

Well considering one is new it's probably the yellowtop?

Test them all. Don't assume.

 

[PuZo 10+ year member]

Just with a voltmeter? Will it cause damage to the good battery if I wait a week or so to change it?

 

[PuZo 10+ year member]

I don't have a voltmeter but I managed to separate the batteries so the new one is connected to the alternator and the second one in the trunk is only connected to the amp. I have a voltmeter on my splitter and it's showing 12.4v(on the yellowtop). Is that normal for "resting"?

 

[MrFoca]

Bad battery will drag a good battery down man.

 

[PuZo 10+ year member]

This is the battery I have for starting:

MotoMaster Eliminator Ultra Flat Plate AGM Automotive Battery | Canadian Tire

What is the best way to test my yellowtop and D975 to see which has more life?

 

[Side Show 10+ year member]

test the battery resting voltage, then but a decent draw on it and test it again.... I had one batt that tested fine until it was put under load then it dropped to around 7/8v and started ******* the pwr from my other batt.

 

[PuZo 10+ year member]

So it is deffinetly the new battery. Drove with it with nothing on and it dropped to 13.2/13.3

What type of battery should I get? Looking to combine it with my yellowtop or xs power d975

 

[jrdnhsnbrg 10+ year member]

So it is deffinetly the new battery. Drove with it with nothing on and it dropped to 13.2/13.3
What type of battery should I get? Looking to combine it with my yellowtop or xs power d975

Your alternator will charge at a higher voltage right after you start the vehicle (especially in the cold) in order to charge up the power that was lost during starting. My car will charge around 14.3V right after starting and die down to 13.4-13.6, it's totally normal. Go get that battery load tested before you do anything else.

 

[PuZo 10+ year member]

Any links for how to do a load test at home?

Will it be okay though with a starting only battery in the front with a yellowtop in the back? Before I had 2 deep cycle and now I'll only have 1 so just a bit concerned.

I'd really like this one for the front.

http://Http://www.saskbattery.com/ecommerce_308.htm

 

[michaellane 5,000+ posts]

So it is deffinetly the new battery. Drove with it with nothing on and it dropped to 13.2/13.3
What type of battery should I get? Looking to combine it with my yellowtop or xs power d975

take it to your local auto store they will check it for free man go today

 

[jrdnhsnbrg 10+ year member]

Any links for how to do a load test at home?
Will it be okay though with a starting only battery in the front with a yellowtop in the back? Before I had 2 deep cycle and now I'll only have 1 so just a bit concerned.

I'd really like this one for the front.

http://Http://www.saskbattery.com/ecommerce_308.htm

You need a specialized tool as far as I know. A shop or parts store should be able to do it for free