GT86 - Flat Battery after 2 weeks...

Soldato
Joined
28 Dec 2007
Posts
11,553
Location
Sheffield
Toyota GT86 had a completely flat battery after just 2 weeks of standing (Not enough power to even operate the central locking), Toyota claim that they've done a diagnostics check and can't see anything immediately wrong with the car.

Does this sound normal at all or worth chasing? We've left cars for much longer than this before and never had any such problems, one thing to note is that when we test drove the car they had to start it with a booster pack then as it wouldn't start in the dealership so not the first time it's gone flat...
 
Dodgy battery discharging quicker than it should? Slightly different situation but I hired a brand new Mercedes Luton van. Parked it overnight on my drive, went to start it next morning and nothing, battery was flat. Enterprise told me it was fairly common due to poor battery conditioning on cars being left unused on forecourts for extended periods of time. New battery was the fix.
 
Do you have the 48ah grey panasonic or the 64ah black toyota battery?

The panasonic ones are prone to failures and as you have seen barely last 2 weeks. The alarms on the car are known to take a lot of power and can sometimes completely drain the battery if they don't arm properly. I had mine replaced in it's second winter as it wasn't getting enough charge to start after 8 miles. 2 years on the new battery can do over 3 weeks without any issues.

It is a known fault and well documented on the forums, but a lot of dealers are frustrating to work with and to be honest don't have a clue. Others will swap out parts no issues.
 
Probably a knackered battery if it has gone flat once already. Plate Sulphation kills a dead battery very quickly, then it wont hold a charge properly.
 
Probably a knackered battery if it has gone flat once already. Plate Sulphation kills a dead battery very quickly, then it wont hold a charge properly.

Modern batteries are shocking.

I have seen Yausa (Generally a pretty decent brand) dead after a single hard discharge from new.

where did it all go wrong?

:(
 
Do you have the 48ah grey panasonic or the 64ah black toyota battery?

The panasonic ones are prone to failures and as you have seen barely last 2 weeks. The alarms on the car are known to take a lot of power and can sometimes completely drain the battery if they don't arm properly. I had mine replaced in it's second winter as it wasn't getting enough charge to start after 8 miles. 2 years on the new battery can do over 3 weeks without any issues.

It is a known fault and well documented on the forums, but a lot of dealers are frustrating to work with and to be honest don't have a clue. Others will swap out parts no issues.

I'll take a look tomorrow morning and see which one's in it, if the's the Panasonic battery do you know if dealers are replacing them under warranty?

Probably a knackered battery if it has gone flat once already. Plate Sulphation kills a dead battery very quickly, then it wont hold a charge properly.

Heard a few people say that if they go flat once the batteries can be stuffed :(
 
As Steep said, a common problem with a specific battery supplied with the GT86. Many owners have replaced theirs with a more powerful one and had no issues. Some dealers will swap out for the newer, larger one under warranty.
 
Mine was under warranty and I know at least a dozen others that were. If your dealer has already tested it and not swapped it out then you might have a struggle to get it done under warranty, even if you try another more capable dealer. If you are often not driving the car for 2 weeks then keep calling them saying it's failing and not suitable. The battery needs its own diagnostic which should have a print out with the result.
 
Had a look the other day and the car has the grey Panasonic battery. Plan is to just wait for the car to have a flat again as the car has since been accepted back from the dealer, next time it goes flat we'll push for it to be replaced before accepting the car back, still have 4yrs on the warranty so plenty of time :)
 
48 Ah is not a lot. I have an RX8 and that has a 75 Ah battery and it is probably easier to turn over than a piston engine.
 
But an RX8 needs an high AH battery to keep the starter spinning fast as possible...

Ah is the capacity and CCA is the punch it gives to turn the starter. They turn over at the same speed as a piston engine. I can not detect any difference in speed. I had a Civic before and that had a very similar battery to the RX8 with only slightly higher CCA for the Civic.
 
Modern batteries are shocking.

I have seen Yausa (Generally a pretty decent brand) dead after a single hard discharge from new.

where did it all go wrong?

:(

When the EU said everything has to be recyclable and not contain harmful stuff. It's also why cars now all have paper thin panels and flimsy interior plastics :/
 
When the EU said everything has to be recyclable and not contain harmful stuff. It's also why cars now all have paper thin panels and flimsy interior plastics :/

Save the planet or nice car interior.

Tough choice.
 
Do you have the 48ah grey panasonic or the 64ah black toyota battery?

The panasonic ones are prone to failures and as you have seen barely last 2 weeks. The alarms on the car are known to take a lot of power and can sometimes completely drain the battery if they don't arm properly. I had mine replaced in it's second winter as it wasn't getting enough charge to start after 8 miles. 2 years on the new battery can do over 3 weeks without any issues.

It is a known fault and well documented on the forums, but a lot of dealers are frustrating to work with and to be honest don't have a clue. Others will swap out parts no issues.

Steep, I've posted on GT86 forums too, but is replacing the battery as simple as swapping one for the other? No prep to do beforehand, etc?
 
When the EU said everything has to be recyclable and not contain harmful stuff. It's also why cars now all have paper thin panels and flimsy interior plastics :/

Yep of course its the Eu as always, sigh

Most people wanting mainstream cars are now pretty fixated on MPG and running costs
So things like panels, interiors etc are obvious places to save weight, look at BMW efficient dynamics from 10-15 years ago
They started on things like panels for those cars specifically, things like swapping bonnet.

They don't all have flimsy interior plastics either. There are like with everything various degrees

I mean compared to my first car (Mk3 escort) the panels rusted like hell, the interior was heavy and thick, but things like the dash cracked in the sun, it was also hard plastic, it had some (limited) exposed metal in the cabin
I would take a modern focus over that any day with its paper thin panels, with its flimsy interior (well its not). I mean who cares about the panels really, they maybe dent slightly less, but they are easier to repair if they do get a dent.

Yet with all that, they are far more recyclable than they used to be. Its called progress ;)
 
As said this is normal for the 86. Some dealers can be funny, but push it if needs be. Mine was replaced under warranty.
 
Steep, I've posted on GT86 forums too, but is replacing the battery as simple as swapping one for the other? No prep to do beforehand, etc?

Cutting the power to the ECU means it might run a it oddly for a while after the battery change, and will have a bit of an erratic idle. Don't worry about it too much, it will settle down after a few hundred miles. One thing you will notice though is the throttle pedal feeling a bit laggy - this is because the ECU needs to relearn the pedal voltage for it's full range of motion. You can force it to do so by following these steps after the battery change:

1. Turn on the ignition, but not the engine (Press engine start button twice without the clutch down).
2. Gently pump the accelerator pedal a minimum of 5 times, ensuring you got through it's full range of motion each time.
3. Start the engine and let it idle for 1-2 minutes until the idle settles.

Best done with the engine warm apparently.
 
Cutting the power to the ECU means it might run a it oddly for a while after the battery change, and will have a bit of an erratic idle. Don't worry about it too much, it will settle down after a few hundred miles. One thing you will notice though is the throttle pedal feeling a bit laggy - this is because the ECU needs to relearn the pedal voltage for it's full range of motion. You can force it to do so by following these steps after the battery change:

1. Turn on the ignition, but not the engine (Press engine start button twice without the clutch down).
2. Gently pump the accelerator pedal a minimum of 5 times, ensuring you got through it's full range of motion each time.
3. Start the engine and let it idle for 1-2 minutes until the idle settles.

Best done with the engine warm apparently.

If the batter has lost its charge already, I'd imagine i will already be running like this.
 
I honestly don't know how cars are even allowed to leave the factory with defects like this. It's 2018 ffs :confused:
 
Back
Top Bottom