Testing batteries

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Feb 17, 2023 | 04:33 PM

Rob89

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Joined: Jun 2016

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From: South Florida

Testing batteries

2021 6.7. I threw the battery tester on the driver side battery. 12.6v and 1225 amps. I know because the batteries are in parallel that the amps is the total across both batteries but curious if the volts is also the combined number across both batteries?

Feb 17, 2023 | 04:46 PM

chadstickpoindexter

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From: Uh oh, CA

You know... I didn't think about this when the dealership tested my batteries recently and told me that they "over performed" at just over 1000A... But being wired in parallel, the voltage remains the same, the amps stack. I think that my batteries aren't doing as well as they could be in my 22 and am thinking about replacing them later this year. The best way to test these are probably disconnected though.

Feb 17, 2023 | 05:09 PM

scraprat

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From: Itinerant

The proper way to test them is disconnected and seperate.

Feb 17, 2023 | 05:15 PM

Ltngdrvr

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Parallel wired batteries doubles the amps, but voltage remains the same.
A test like this tells you nothing about battery health, a bad battery can still show proper voltage but not stand up to a load.
Only proper battery test is to test them individually(one disconnected) and use a proper LOAD tester.

Feb 18, 2023 | 09:55 AM

HRTKD

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Joined: Oct 2015

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From: Wyoming

6+ years on one of my OEM batteries. The other one was replaced ~4 years ago. They're both OK. I put a CTEK smart charger on the truck when it sits in the garage. The truck is not my daily driver, so it sits in the garage for weeks at a time, months at a time in the winter.

Feb 18, 2023 | 12:47 PM

Rick Cargo

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From: Green Acres, Ca.

I only got 26 months on the original batteries and only 13 months on the warranty replacements. Put me in a set of nice AGM batteries and called it a day. Complained to Ford about only getting 13 months out of the replacement batteries even though they were out of my original warranty. I ended up getting a $376 check from Ford.

Feb 20, 2023 | 08:17 AM

rufushusky

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Joined: Jul 2011

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From: Walpole, MA

Quote:

Originally Posted by Ltngdrvr

^^^ Ditto, need to isolate them to determine if one is stronger than the other. Since they are in parallel a weak battery will wear down a stronger battery over time. Also your testing (in theory) 1500 to 1700 CCA's, you need a heavier load tester. A 100 amp load tester won't make these batteries sweat enough. A high amp carbon pile is the preferred way to test these batteries.