Battery life on Discovery 4

Your information on how our alternators is completely wrong. If you ever watched the voltage fluctuation while the engine is running you would retract the reply you made.

Hi Mike,

Based on the words that you have used, I have offended you...this was not my intention.

But I will go on further based on information that I have read and from those in the industry....without any intention to offend.

1. My agm exide factory battery fitted to my D4 needs a boost voltage of 14.4 and a float voltage of 13.6. Info supplied by exide technologies in the US.
2. My alternator only ever reaches 13.7 and as low as 12.8. Float voltage is only a guide but irrelevant in battery life. Sat NAV only shows surface voltage.....not state of battery condition.
3. Topix confirms how the alternator works, and explains how the alternator, when the surface charge reaches 13.7 from memory, will reduce power input and cut back in at around 12.8. Not a recipe to look after AGM batteries.
4. My uncle is an auto sparky, and as a person in the business, he has told me that the modern alternators never truly charges a battery to the full amount needed to prolong battery life. He has checked my charge output and confirmed its works within factory spec....but it will never full charge my battery.
5. I have a client that works for exide technologies in Perth Western Australia. He constantly sees issues with modern alternators not providing a true deep charge for batteries, and hence premature battery failure.
6. Southern LR (where I purchased my D4) also recommended a battery charger to look after the batteries. I told them that I have always done this and will continue to do so. They see failed batteries regularly due to the function of the alternator.
7. My neice works for Toyota. The Landcruiser also has a "smart" alternator, and they are constantly replacing batteries.
8. And just based on my own personal experience, a smart charger looks after batteries better than any alternator ever will.

I personally don't expect to need to replace my battery in my D4 in 5 years....I have never actually had a battery replaced on any vehicle to this date. Maybe I am doing something right by using a smart charger each month and not relying on factory alternators ?

I am no alternator/battery expert, but always listen to others who are experienced in their chosen field as their advice is invaluable.

Brett.....

discotwinturbo said:

Vehicle alternators have never "properly" charged batteries from what I understand, and with newer ones like the Disco the alternators only switch on when needed, thereby never giving modern batteries what they need.
I have always put my vehicle batteries on a smart charger once a month and have never had a battery last anything less than 5 years.
My previous 4wd battery was 7 years old before I sold the car, and my Touareg battery is now 5 years (on a diesel). My D4 diesel is 18 months old and never experience low battery issues.
Smart charging once a month seems to work for me...preventive maintenance.
Brett....

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I knew that was true on my bikes and always used a battery tender on the weekends. Never done it on my cars though. Good advice.

discotwinturbo said:

2. My alternator only ever reaches 13.7 and as low as 12.8...

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This morning was chilly (some 5 deg below freezing) and my 2011 LR4 sounded like the starter was struggling. That prompted my to pull out a voltmeter and poke around. An adapter in the cigarette lighter makes for an easy place to connect a voltmeter to monitor actual system voltage. Battery water was a little low...hopefully topping off the water plus overnight charge will restore the battery (~2 yrs old, 45K mi).

With the vehicle off the voltage as ~11 V (indication of dying battery). With the vehicle running, voltage was 14.3 to 14.5 V. I put a trickle charger on the battery, and also checked the open circuit (unloaded) voltage for the charger...it is 14.4V (basically the same as the alternator produces).

Maybe the "smart" alternators are different for other markets, but at least with my USA spec'd LR4 the alternator is producing the same charge voltage as an trickle charger.

umbertob said:

Unless there is an electrical issue, in my experience the stock Varta battery is engineered to fail a split second after your factory warranty is up... (4 years or 50K miles, whichever occurs first.) The Interstates they use as replacements in North America - there are no Vartas available here - seem to have a longer life. I read Land Rover is starting to use AGM batteries on certain models, but the battery on my 2013 LR4 is still the flooded type.

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Funny post. My 2010 Range Rover HSE is 2k out of warrentty and battery seems be failing. They do seem to engineer them perfectly to fail once the warranty expires.

Canvasback13 said:

Funny post. My 2010 Range Rover HSE is 2k out of warrentty and battery seems be failing. They do seem to engineer them perfectly to fail once the warranty expires.

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I had to get mine replaced at 48k miles.

I am still under warranty, but still went to Sears to buy a Die Hard AGM for $200. Before I did that, wasn't able to watch an entire movie at a Drive-in where you are not allowed to keep the car running. Was kind of annoyed that the system cut out before the movie ended. Haven't gone back to try with the new battery but my guess is that it might last now that it's new and not the factory one. Also I have the upgraded HK Logic7 system so I take it that the larger amp probably draws more power than the standard one.

jpjp said:

I am still under warranty, but still went to Sears to buy a Die Hard AGM for $200. Before I did that, wasn't able to watch an entire movie at a Drive-in where you are not allowed to keep the car running. Was kind of annoyed that the system cut out before the movie ended. Haven't gone back to try with the new battery but my guess is that it might last now that it's new and not the factory one. Also I have the upgraded HK Logic7 system so I take it that the larger amp probably draws more power than the standard one.

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Was this the battery you bought?

http://www.sears.com/diehard-advanc...p-02850793000P?prdNo=1&blockNo=1&blockType=G1

I only have 20,000 miles and my battery seems fine, but since I have a few off-road lights and a winch connected, I wanted to change out my battery before I get any issues.

Thanks for confirming! I really don't mind spending the money, but would rather get the best possible battery I can for my 2013 LR4 HSE Lux. Thanks!

That's the one!

On a previous thread people have mentioned that you can place a slightly larger battery in the casing without modifying, but I sent my wife to Sears because I was out of town and didn't want to deal with figuring all that out while not physically being there. I would have liked to have had the largest battery possible. Right now my needs don't call for a 2nd battery, but I do think I would consider that in the future. My wife is 6 months pregnant and I don't think I'm going on any extended camping trips in the next year or so.

My 2015 just ate its first battery at 5500 miles. Dealer replaced it under warranty with an Interstate. Service tech says its a "much better" battery.

I had quite the unusual experience when mine died. For a week or so it was a periodic "labored start". It then went completely dead one morning, no clicks just dash lights with a bunch of faults. I waited a minute, turned all the power items off, AC, lights, radio, etc. Tried it again. This time the starter solenoid fired a few times. Again, waited a minute, now it rolled over, but no start. Waited another few minutes, what do you know? It started. Never had that experience before.

Next morning it was dead again. I jumped it and drove it in.