Battery Drain.

[Olazz]

If two yellow tops that run the car are squeezed in on one battery tray as is often done you may find one is aging much faster than the other due to being exposed to more heat and is constantly discharging the good one.

John, batteries are at each side as stock, third YT in in rear in Luna PAC.
May have solved the issues with some judicious re-wiring done to get truck through its MOT today. Will wait and report tomorrow morning if battery has run down.

 

[MuckyPup]

2. Yes all 3 are Yellow tops. I wanted batteries that could handle the possibility of regular deep discharge and still be useable.

If two yellow tops that run the car are squeezed in on one battery tray as is often done you may find one is aging much faster than the other due to being exposed to more heat and is constantly discharging the good one.

While heat is certainly a factor in battery life that is not the real reason "twinned" batteries die at different rates like your example.
They die because the more simplistic charging systems simply link the two batteries together whenever charge is available, i.e. the alternator "sees" one big battery and charges it up by sticking 14.2v in it.
What the alternator doesn't know is that one battery started off with or became less charged than the other and what it's actually doing is constantly undercharging one or overcharging the other.
The sum you see is the same as far as the alternator is concerned..........
In an ideal world we would have an intelligent DUAL (not split) charging system or we'd charge them individually on a regular basis to maintain their match, that or swap them around once a month
This is also the sort of thing where "mate a" does it one way for years without problems yet "mate b" wrecks batteries the day his warranty runs out.

 

[Jon Wildsmith]

While heat is certainly a factor in battery life that is not the real reason "twinned" batteries die at different rates like your example.

You've got the wrong end of the stick, I wasn't describing a split charge system but the standard OEM cold climate configuration relocated to a single OEM tray, but that's not what Olazz has anyway.

 

[MuckyPup]

I'm fairly sure the OEM cold climate is actually a basic twinned system as far as charging is concerned.
I've yet to see one with balanced batteries that's for sure !!
But hey, i've been wrong loads of times...........

 

[Jon Wildsmith]

I'm fairly sure the OEM cold climate is actually a basic twinned system as far as charging is concerned.

It is, that's why it would cause a discharge problem if one battery is failing

 

[Olazz]

Well after the rewiring exercise of the lights & spots in particular and the installation of new earths etc to switching side (so I was told by the sparky), the truck has sat for 2 days with zero drain on batteries !!!

So how could the faulty spot light/headlight wiring have been the cause of this?

 

[Julian Voelcker]

So how could the faulty spot light/headlight wiring have been the cause of this?

The headlights and spots would have been wired to the batteries via relays with the intension of drawing power from the batteries to power the spot light/headlight when switched.

The only way this sort of circuit can draw power is if the relays get damaged, most likely through salty water, shorting out the circuit.

 

[Olazz]

The only way this sort of circuit can draw power is if the relays get damaged, most likely through salty water, shorting out the circuit.

Not sure how salt water would get into and up to the battery area to cause a short

 

[Andrew Prince]

Have you driven your 80 in winter at all? In the UK? When it's been raining? (Ok ignore the last question!)
The Highways Agency and their friends kindly applied salt, purchased with your tax contribution, to the road and the UK weather did the rest - salty water flung up as spray while driving in winter

 

[Olazz]

Thanks Andy,

I'd buy that if I was using the truck on a regular basis during the winter and driving in all conditions. The truth is the Truck's been sitting in my garage for most of the winter and probably been out 4 times since July 2011. In any event the relays are pretty well protected inside the battery box/cover; I also use dielectric grease on all terminals and posts. I think that explanation is highly improbable.

 

[Julian Voelcker]

Not sure how salt water would get into and up to the battery area to cause a short

That was what I was thinking, but only explanation I could think off. With the wiring in place it would have been easier to pin down the exact cause.

The HID relays were all up at the back of the battery box, where were the relays for the spots? Were they some sort of PIAA arrangement?

 

[Gary Stockton]

Lollie ( )

Can't find your post on wanting headlights - but found an old link I had. Not OEM lights, but seem to be pretty good nonetheless.

80 Series Headlights

 

[Andrew Prince]

I'd buy that if I was using the truck on a regular basis during the winter and driving in all conditions. The truth is the Truck's been sitting in my garage for most of the winter and probably been out 4 times since July 2011. In any event the relays are pretty well protected inside the battery box/cover; I also use dielectric grease on all terminals and posts. I think that explanation is highly improbable.

I take your point - if the salt spray was THAT big an issue, then we'd all be suffering from it presumably. Who knows - it could just be the luck of the draw. (pun unintended )

 

[Olazz]

Lollie ( )

Can't find your post on wanting headlights - but found an old link I had. Not OEM lights, but seem to be pretty good nonetheless.

80 Series Headlights

Now I've been called many names in the past, but never, ever, has anyone called me Lollie!!
I might get CP to change my moniker from Olazz !

Thanks for the link, you're my china!

 

[Gary Stockton]

We could start with the 'Orance!! Orance!!' but I don't know where to find the 1000's of Arab horsemen and camel cavalry!!

Sorry - sad reference to the 'of Arabia' fame