Thread: NISSAN PATROL BATTERYS

To any auto sparkys on here,yr info greatfully received.My old patrol getting harder to start,batterys been in about 7 yrs,12 volts batterys running parallel.I have a third battery i carry as a spare for in the back blocks in case something goes wrong or somebody else needs some power.
I took out one battery and fully charged it to 13.2 volts,over 5hrs it dropped to 12.6 where it should stay a lot longer.Over the next 60hrs it only dropped .24 volts=1/4 of a volt.Do you think this battery still ok,or one cell dying out?Il take out other battery and see if it drops about the same time as 1st battery.I did a crank test,batterys dropped to about 9volts for a couple of seconds then went back up to 12.6 at idle.
When truck is running over 800rpm,alternator charging around 14.5 volts, all good.
Truck only gets a short run once a week or so,till i go hunting once or twice a month.
Thanks for yr time in reading this.

At 7 years old I would think they could be on the way out. got my Paj oct 2016 and it has twin batteries as well. It is at the point you know it isnt starting quite as snappy as it used to. Only 12v system
Disconnected one for a couple of days it it was sitting at 12.9.
You could have dodgy cells which have voltage but not amperage.

you can voltage check with a meter as much as you want, you need to load test it. with engine off measure the voltage then throw everything on. lights, heater fan, anything.that drags power. then see what it drps too.
7 years is pushing it though

The patrol nz new,factory 12 volt parallel.Iv had the truck nearlly 16 yrs,this is the second set il have to buy.So guess she s done well.1st set lasted about 7yrs.Thore 750cca batterys turn the old 4.2tdi over 1st pop.

12.6v is a fully charged battery voltage but as it charges at 14v they can take a while to drop down. I suggest checking the voltage in the morning it should be at 12.6v
You say it's at 12.6 at idle but also say it's charging at 14v? 14v is normal if at 12.6 that points to the alternator not charging. As above the only way to test is to load it up but it needs to fully charged as all flat batteries fail. At 7years one cell will be down dragging the whole battery down.
P.S. 12.5v is considered flat and 12.4v is considered fully discharged.

If you need new batteries try "battery cell".
Online shopabout 1/3 less than the shop

Originally Posted by widerange

If you need new batteries try "battery cell".
Online shopabout 1/3 less than the shop

battery cell is awesome for unusual stuff, as for normal sizes lead acid etc its just ok

Originally Posted by mimms2

Are batteries permanently parallel?? Could have a situ with one cell gone, so always acting as parasitic draw from the good battery. would also pay to wire in an isolator if it doesn't already, though I have a feeling some of these were 24v starting? but 12v for everything else.

. Or fault with low internal resistance.
But yeah, might be time to shell out for a new pair and retire these to camp batteries.
Even "maintenance free" ones you can often pry/smash off the tops to get to the cells/plates which will allow you to top up and/or measure electrolyte gravity (which will show a parasitic cell)

After making sure there's enough water in em, an "equalise" charge (about 16v) will help to desulphate plates and destratify the acid and might just give em a new lease on life.

The 12V Run/24V Start is an odd Landcruiser thing. The Nissan Patrols are 12V and the Nissan Safaris are 24V (NATO spec).

When patrol doing 800rpm or more she s charging 14.5volts.Idling around 500rpm,not charging and batterys sitting on 12.5-6 volts.Patrol had brand new alternator about 4yrs ago.

Originally Posted by Trout

When patrol doing 800rpm or more she s charging 14.5volts.Idling around 500rpm,not charging and batterys sitting on 12.5-6 volts.Patrol had brand new alternator about 4yrs ago.

Hmmm, sounds dodgy. Battery condition is just the tip of the iceberg. Reckon the whole trucks on the way out.
Tell ya what, I'll save you the hassle and take it off your hands for 5K

Judging by age and the fact is taking some time to start you are right , its on the way out, Similar in my truck put on one of these testers a group of us got a couple years ago, ( https://www.amazon.com/BA9-40-1200-D.../dp/B00IZFNJ6Y) truck was 800CCA had 450CCA only and S tate of health osf48% from memory, looks good voltage wise but most of cells defective took 2 to 3 seonds minimum to start, put in the New Varta H3 , one click and instant start, was advised that a weak battery is hard on car starters but I am not an expert, I beat winter will find you out!!

Alos cheaper and good tester is this one https://www.aliexpress.com/i/3284803...71223306Nc51iK

Good luck

This will tell you everything you need to know.
https://www.supercheapauto.co.nz/p/s...er/214445.html

Originally Posted by 2post

This will tell you everything you need to know.
https://www.supercheapauto.co.nz/p/s...er/214445.html

Only problem is no holes in batterys to put it in.Little green indicator down viewing circular window instead.Showing green.

Originally Posted by mimms2

Are batteries permanently parallel?? Could have a situ with one cell gone, so always acting as parasitic draw from the good battery. would also pay to wire in an isolator if it doesn't already, though I have a feeling some of these were 24v starting? but 12v for everything else.

. Or fault with low internal resistance.
But yeah, might be time to shell out for a new pair and retire these to camp batteries.
Even "maintenance free" ones you can often pry/smash off the tops to get to the cells/plates which will allow you to top up and/or measure electrolyte gravity (which will show a parasitic cell)

After making sure there's enough water in em, an "equalise" charge (about 16v) will help to desulphate plates and destratify the acid and might just give em a new lease on life.

just as a sideline (though battery related) if you have a micron brand alarm system there is a 2nd battery in the outside siren. always change both !

sorry to hijack the thread but might save a few people some $$$

Originally Posted by XR500

Hmmm, sounds dodgy. Battery condition is just the tip of the iceberg. Reckon the whole trucks on the way out.
Tell ya what, I'll save you the hassle and take it off your hands for 5K

Sorry mate 5k just wont cut,lols.Lot of ks left in the 4.2tdi.