P38A Battery lifespan

1995 4.6 GEMS 206k

I have had the big MF3 1000cca battery for about 4 or 5 years and no problems
Since Covid mileage has been cut drastically but she always started fine
She was unused for two weeks and battery was flat. Only just enough to light dashboard.
Jumped her and no problems.
Drove her all week about 30 miles each way every day again no problems
Didnt drive all weekend and same no starting today
Then no start to come home tonight.

Question: Does a battery just die with no warning?
Previously there was no problems at all
Your thoughts would be much appreciated

My Hankook died suddenly after 1 yr
So did my Numax

They can just die, mine was fine in the morning, after work in the carpark she was dead!!

They can just die, but you need to fully charge with a proper charger to give it half a chance

Never realised they can just up die. Just like sheep then
After fitting it I had never had to charge it but let the alternator do its stuff

www.optimabatteries.com/experience/blog/fact-alternators-are-not-designed-to-charge-dead-batteries

Ignore the red top/yellow top ad at the bottom.

Very interesting thanks Ratae
I will stick charger on her as soon as possible but why did it die originally?

oakey said:

Very interesting thanks Ratae
I will stick charger on her as soon as possible but why did it die originally?

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2 words..

Charger on now

You could have battery drain somewhere

Over the years I have had many differant cars vans trucks etc and many makes of batterys.
If you can afford it fit an AGM they are more resilient to charging and can handle more of a deep cycle and recover from it better than LAC ones.
Go to tayna online 24 hour delivery and every battery make for less cost and the batteries are brand new not old...........when you buy fro say halfords the battery could have been sat for months and gone past its recharge dates and may only be 85 % capacity to start off with.
Why does a battery die ? well its normally a plate that dies in one of the end cells, this is due to a charge of 14.6 volts replacing heavy heavy drains at start up the colder the worse and all the modules that come to life doing so, diognostic readers cause all these modules to wake up and a huge discharge so begins.
Always monitor batterys bewars, look for any bulges in the outer plastic miss shaped forming etc.

I saw a video on facebook on a talbot express owner asking a question yesterday, he had one water fill open van running and smoke pouring out from the top looking down in to it ! I suggested he switch off and that acid in the cells may lead to harm being caused and the reply was "o ok thanks Ill get a new one in a few months it still starts"

LAC's are never "sealed for life" watch and keep an eye on water levels and top up when required as thats what keeps em going and may save a few quid through out the year.

If you can run an extension cable where you park and keep a small charger under the bonnet and just hook up, that way you will keep the battery 100% and it will last longer.

Luxuray 4x4 do a dual battery kit but the price of £99 is high for one relay and a few wires and as soon as I can find out what realy it is I am planning on making one and mounting a battery in the boot as so it gets 100% dual battery start.

oakey said:

1995 4.6 GEMS 206k

I have had the big MF3 1000cca battery for about 4 or 5 years and no problems
Since Covid mileage has been cut drastically but she always started fine
She was unused for two weeks and battery was flat. Only just enough to light dashboard.
Jumped her and no problems.
Drove her all week about 30 miles each way every day again no problems
Didnt drive all weekend and same no starting today
Then no start to come home tonight.

Question: Does a battery just die with no warning?
Previously there was no problems at all
Your thoughts would be much appreciated

Click to expand...

Lots of short journeys and/or leaving a P38 unused for periods leads to an under charged battery, lead Calcium batteries rapidly suffer from sulphating when under charged or flat and yes they can finally die without warning.
Kept fully charged batteries will last a decade or more. On the P38 under charging is often caused by the alternators having a set point of 13.8 volts, not enough to charge a Lead Calcium battery.
In your particular case, battery capacity my have been reduced by being kept under charged and there may also be a drain from the BECM.
My first MF31-1000 lasted 8 years and was taken out by alternator failure.
I keep the batteries on all my cars topped up with solar chargers.

Its the new type alternator cos last one had a crack in casing,
Dont do short journeys, normally about one trip of 30 miles each way once or twice a week and a couple of hundred each way every couple of weeks.
Never had any sign that battery was not fully charged
If there was battery drain then it would have shown earlier I would think.
The RF aerial was already disconnected and fob only worked when next to car.
Had charger on all last night and had to jump her this morning

oakey said:

Its the new type alternator cos last one had a crack in casing,
Dont do short journeys, normally about one trip of 30 miles each way once or twice a week and a couple of hundred each way every couple of weeks.
Never had any sign that battery was not fully charged
If there was battery drain then it would have shown earlier I would think.
The RF aerial was already disconnected and fob only worked when next to car.
Had charger on all last night and had to jump her this morning

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Fink its deddid

Though, are you sure there's no high amp drain? If it's bigger than the charger puts in then it's all downhill

My charger is only 5A, if the battery is flat because the car isn't going to sleep, its not enough to charge the battery

if was a hugh amp rdrain then the battery would have been totally really flat after teh two weeks but it wasnt totally dead just very dead lol

What was the guy you recommended for batterries Kermit?
And anyone know what the mf31 is called now?

oakey said:

What was the guy you recommended for batterries Kermit?
And anyone know what the mf31 is called now?

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I don't think i did but i got mine from battery megastore, hankook mf31

Thank you sorry my mistake thought was you got battery built special

oakey said:

What was the guy you recommended for batterries Kermit?
And anyone know what the mf31 is called now?

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HANKOOK MF-31 1000

Is the Victron charger they recommend any use?
Is 12 V 15 A

Victron have a good name but tend to be quite expensive from what I've seen. If it's a justified price i can't comment