Low Battery: Start Engine - Battery fine...Alternator working great

[gsxr]

14.75 volts with engine running seems a tad high, now I need to go check my LR4 with the engine running! This only indicates the ALTERNATOR is working.

The battery really needs a load test to determine if it's good, failing, or bad. Most FLAPS/McParts stores will load test for free, hoping the battery is bad so they can sell you a new one. Before testing the battery must be fully charged though. If you have a trickle charger, connect that for a couple days, then get the battery load tested. Some of the methods described above are a rough test that may pinpoint a definitely bad battery, but if it's that bad, you'd likely have obviously slow cranking speed or other symptoms.

If you do have to buy a new battery, I second the recommendation for an H8 (Group 49) AGM with the best warranty you can find. Some brands are only 3yr replacement, some are as much as 5 years.

Interestingly, the nEverStart brand at Wal-Mart appears to be a quality German-made battery with 5yr full replacement warranty, at a price well below any other vendor (~$150). Edit - photos on their website now show 4-yr warranty, hmm, I'll have to check what they have on the shelf, when it's safe to venture back out into the public. If no store in your area has them in stock, the website will show "not available". And, price seems to vary by region, I'm seeing $150 in CA but $170 now in ID? ?!!!!

https://www.walmart.com/ip/EverStart-Platinum-AGM-Battery-Group-h8/40647529

 

[ktm525]

This is not necessarily accurate. I've seen batteries that could hardly light the brake lights show 13+ volts with the engine off. Your alternator charging at 14.75 with the truck running seems to imply that it thinks the battery charge state is low. I would get the battery tested at your local auto parts store to be sure.

If you've replaced the battery, i think there is a setting that needs to be reset in the ecu to make it know the battery is new again.

Measurements have to either be taken after 1 min of load with engine off (ie. lights on) or a few hours after shutdown.

 

[Strizzo]

Measurements have to either be taken after 1 min of load with engine off (ie. lights on) or a few hours after shutdown.

I can tell you I’ve seen a battery read 13.2v, then not be able to turn the motor over, drop to 10v and climb back up to 13.2v again. Batteries have many different failure modes so saying xx.xV means the battery is good or bad is too simplistic, and a load test is the only way to know if the battery is good or bad.

 

[ktm525]

A proper load test is best but if a battery fails the simple at home multimeter test then there is no need to drive all over talking to slack jaw idiots at the auto parts store. Having just replaced my 5th battery (between my LR3 and 4) it is pretty evident when they get weak. This time the LR4 didn't give a low battery warning rather a random check engine warning with no corresponding code. You can almost set the clock on a H* though. 4 1/2 years. All have failed a few months either side of this.

 

[RoverRover01]

My Sport gives a “low battery” mode warning every time I shut down the engine, and stay in accessory mode, and have radio on, like when I shut down to talk on the phone or waiting to meet someone — volume on radio even decreases when the low battery mode kicks in —- I have a 4 month old top of the line battery, had electrical/charging system checked a few weeks ago - all is good.

Just drive it till it won’t start or it seems weak starting. My experience with my LR’s over the years is this — when the battery gets really weak, or at the edge of death, you’ll start getting lots is weird stuff happening. Maybe some never seen before odd warnings, lights coming on you never knew existed —- Drive on Garth!

 

[ktm525]

Good advice and carry a portable booster pack (my new one is like 6x4x1") in the back.

 

[ktm525]

My Energizer battery arrived through Costco today. Very impressed with the packaging and a 2/20 sticker. A few days straight to my door. $250 CAN ($170 US) is a good price for a AGM with 5 year replacement warranty and 50% for a few years after that. No idea who is making the Energizers.

 

[avslash]

My Energizer battery arrived through Costco today. Very impressed with the packaging and a 2/20 sticker. A few days straight to my door. $250 CAN ($170 US) is a good price for a AGM with 5 year replacement warranty and 50% for a few years after that. No idea who is making the Energizers.

View attachment 10795

Word on the street is that it is rabbits....

 

[ktm525]

lol. Says Clarios.

 

[Aretools]

Need a New battery, I had an interstate last only 1.5 years. my assumption is that the battery has a dead cell. The LR4 is very sensitive to voltage, I would recommend to getting an Iland diagnostic tool or something similar. The Iland tool from roverparts.com saved me thousands of dollars by removing faulty codes on other issues.