P400 Battery Replacement Questions
#11
Wow, 4 years and you're just replacing the battery! I am at two years and am almost to my 4th. There are apparently two manufacturers of batteries. The Exide and the Interstate. If I was to guess which one is better, I would say the Interstate. It is the Methuselah of my battery troop that has been installed. Lasting nearly a year! I hope , ever so hopeful, that this time, when they do the service bulletin, they have rightfully identified the vampiric module that is endlessly killing them. Really it is quite frustrating, as it makes me not really trust the vehicle for longer periods in the field unless I bring some kind of charger, battery box, solar panel or magic charm. Day before yesterday, 1 hour on the Interstate, coming back in from the field and already the battery is at 11.9 volts (I now keep a full time battery voltage monitor connected). Back on its IV drip from the CTEK. BTW, just for the battery or should I say batteries, the extended warranty is worth every penny.
Anyhow, yes it is under the passenger seat. The trapdoor has a loop to pull it up and detach it. There is a foam block on the backside that just lifts out, giving access to two bolts that hold down the battery. Then a matter of releasing the negative terminal first, then the positive and horsing it out of its well. It does have two installed handles. You computer will lose some of its adaptive engine running data, but it gets it back in 30 minutes of running.
Anyhow, yes it is under the passenger seat. The trapdoor has a loop to pull it up and detach it. There is a foam block on the backside that just lifts out, giving access to two bolts that hold down the battery. Then a matter of releasing the negative terminal first, then the positive and horsing it out of its well. It does have two installed handles. You computer will lose some of its adaptive engine running data, but it gets it back in 30 minutes of running.
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merrion13 (02-04-2024)
#12
We replaced our and it's fairly simple and straight forward. You will need to move the passenger seat forward, but there is no need to remove it. The access door offers sufficient room to get the old one out and the new one in, but it's a heavy battery and not the most convenient placement so it will take a little effort. I put a battery charger on the terminals under the hood just because I didn't want to risk losing any programming (that's probably not necessary, but years ago I lost my radio presets, and I've done it ever since)
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DonMitsu (02-05-2024)
#13
I'm almost at 41K miles and nearly 4 years of ownership and the Low Battery Warnings are becoming more frequent so it feels like it might be time to replace my battery.
For those who have done it, is it a simple swap, or is there programming that needs to be done at the dealer? Are you able to do the swap without removing the passenger seat, or does it require pulling that out to replace? Lastly, did you use the exact LR part, or did you replace with a non-LR solution?
I'm looking for more information on if this needs to be done by dealer or if I can simply do it, thank you!
For those who have done it, is it a simple swap, or is there programming that needs to be done at the dealer? Are you able to do the swap without removing the passenger seat, or does it require pulling that out to replace? Lastly, did you use the exact LR part, or did you replace with a non-LR solution?
I'm looking for more information on if this needs to be done by dealer or if I can simply do it, thank you!
I recommend you get the original LR battery.
The battery on our Defenders is constantly monitored by a control unit, the one you see on the negative pole, this control unit controls the efficiency of the battery and over time modifies the charging times and currents in relation to the absorption capacity, over time with used battery uses different values.
When you install a new battery, you have to "tell" the control unit that you have installed the new battery, and it resets to the original values.
to do this you have three options, Dealer, Pathfinder jlr, or Gap Tool.
Marco
The following 2 users liked this post by mmbanf:
Parukas (02-09-2024),
the continuum (02-22-2024)
#14
hi, you have to replace the battery with an equivalent battery, same type (agm), same amperage, same starting current.
I recommend you get the original LR battery.
The battery on our Defenders is constantly monitored by a control unit, the one you see on the negative pole, this control unit controls the efficiency of the battery and over time modifies the charging times and currents in relation to the absorption capacity, over time with used battery uses different values.
When you install a new battery, you have to "tell" the control unit that you have installed the new battery, and it resets to the original values.
to do this you have three options, Dealer, Pathfinder jlr, or Gap Tool.
Marco
I recommend you get the original LR battery.
The battery on our Defenders is constantly monitored by a control unit, the one you see on the negative pole, this control unit controls the efficiency of the battery and over time modifies the charging times and currents in relation to the absorption capacity, over time with used battery uses different values.
When you install a new battery, you have to "tell" the control unit that you have installed the new battery, and it resets to the original values.
to do this you have three options, Dealer, Pathfinder jlr, or Gap Tool.
Marco
#15
The following 2 users liked this post by mmbanf:
the continuum (02-22-2024),
WTFChuck (02-06-2024)
#16
Very interesting stuff.
It's amazing how even a battery change can be made more complicated by the modern systems. I'm guessing it's not unique to LR.
I've disconnected my battery a number of times to do stuff and reconnected without any issues. How does the CPU distinguish between a new AGM battery and the old one I've reconnected I wonder?
It's amazing how even a battery change can be made more complicated by the modern systems. I'm guessing it's not unique to LR.
I've disconnected my battery a number of times to do stuff and reconnected without any issues. How does the CPU distinguish between a new AGM battery and the old one I've reconnected I wonder?
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robn (02-06-2024)
#18
Only a few low battery warnings over about a one month period. At which point they ran 2-3 charging tests and it “failed”, so I got it replaced. The TMU being out also at the same time helped the cause apparently. They can be tied together in some way per my advisor, but I can’t recall. Cause I thought they were independent of each other. But hey, got about $1,000 worth of free batteries to last me another 3.5-4years.
#20
I did this replacement Sunday myself; I hooked my Ctek charger/tender to the terminals under the hood, then fully raised/moved seat to front to remove existing battery. I had to remove the black metal bracket shown in the photo below in order to fit the replacement battery back in (I then put the bracket back in after the battery was nestled in).
After two days of driving car seems OK. I have a trip tomorrow that will require 4 hours of driving which should help see if any issues.
After two days of driving car seems OK. I have a trip tomorrow that will require 4 hours of driving which should help see if any issues.