Flat Aux battery

[Richardc]

My 2014 Outlander has now suffered 4 incidents of failing to start due to a flat AUX battery.
Has anybody else experienced similar and if so what was the fix.
My local garage has now spent 4 hours looking at it to no avail. They've been on the phone to Mitubushi but they just claim I must have left it on.

It's possible it happened the first time but I've been extremely careful since and definitely know that is not the cause.

What I've observed.

• The AUX battery won't recharge if the drive battery is full. The cable just turns off. I've had to recharge the AUX battery with a conventional battery charge or use a jump box, both connected to the big tag in the fuse box. I consider this a design flaw,
  My AUX battery seems to go flat if the car is left parked up for several days. So far no cause has been found. The Battery has been tested a couple of times and passed both times.

I really like my outlander so it would be a real shame to have to get rid of it for such a trivial problem .

 

[greendwarf]

Surely there are only 3 possible faults causing this :- faulty battery not holding charge; battery not being re-charged during normal use; something not switching off and draining it. All of these the dealer should be able to identify in a matters of a few hours of testing/monitoring. If they can't, then it must be something you are doing!

 

[Richardc]

If I drive daily and then recharge overnight, everything is fine.

It's only when left for a few days, that the problem occurs. It even happened when we were away for a week even though I had left it plugged in. As the drive battery was full, it did not keep the aux battery topped up.

The courtesy lights work, It seems in a to try to start, there is a noise from the engine and then all the lights go out.

 

[anko]

IIRC, it makes a difference what spec you have. Versions with WiFi recharge the aux battery from the EV battery every day at 14:00 hrs. Other versions may not do that.

 

[Richardc]

It's a 2014 and does not have WiFi recharge. Have you seen this work. I know my charge lead turns off if the drive battery is full.

 

[jaapv]

Local garage on the phone to Mitsubishi? What is it doing there? This is a car that can only be serviced properly by an authorized dealer. It does not surprise me that you have problems. A real Mitsubishi dealer will hook it up to the service computer, read out the logbooks and if they cannot diagnose the fault they'll link through to the service center of Mitsubishi in Japan. They did that when my car developed a weird fault.

Anyway, it appears that the daily recharge from the main battery does not take place. As it does seem to recharge when used, the most logical conclusion is corrupted software.
@ Anko: Are there versions without WiFi then? That is news to me.

 

[anko]

It's a 2014 and does not have WiFi recharge. Have you seen this work. I know my charge lead turns off if the drive battery is full.

So does mine. But it turns back on at 14:00 for a brief moment.

As a matter of fact, the car signals the charge station when is done charging and as a response the charge station disconnects the main leads. As soon as the car signals it wants to charge again (for example because you turn on the heater or when the aux battery needs recharging, the charge station will reconnect the main leads.

 

[anko]

@ Anko: Are there versions without WiFi then? That is news to me.

I thought the ones without electric heater didn't have WiFi? Maybe I am confused and what I said applies to when WiFi is not active because there are no connected phones?

 

[HHL]

@ Anko: Are there versions without WiFi then? That is news to me.

I thought the ones without electric heater didn't have WiFi? Maybe I am confused and what I said applies to when WiFi is not active because there are no connected phones?

The base model that was sold here in Australia does have an electric heater, but no wi-fi........

 

[Richardc]

By local garage, I meant the franchised Mitsubishi dealer. They could not find anything so appear to have a support line back into Mitsubishi which makes sense. These cars are more computer than mechanical.

My car does not have the electric heater. When I asked the garage to enable wifi they said it did not have the heater and gave the impression that it also did not have wifi.

As a result, I fitted a time clock to my recharger. I only recharges between 1am - 8 am unless I override it. Otherwise it will recharge when I get home from work, right during peak demand. If it does turn on at 2pm, then it would fail. That could explain why the aux battery failed to recharge when plugged in. Still a nuisance, since if you have a full drive battery, you may to wait 24 hours before it recharges the aux battery.

Its pointing towards something discharging the aux battery or something intermittently having a big power demand at startup. There is a lot of noise from the engine when this occurs. I'm guessing this is the various clutches moving.

 

[Richardc]

Garage has been told by Mitsubishi that other PHEVS have experienced similar problem even though AUX battery tested ok. They are replacing the battery on Friday. I'll let everyone know whether this solves the problem.

 

[Ianr]

Quite a long history with Nissans and the same issue. They do replace under warranty or had a nistory of. I suspect as part of the group a lot of suppliers are the same

 

[Richardc]

Well, despite have a brand spanking new AUX battery it let me down again so back to the dealer today.
I'm suspicious there is a relationship with opening the tail gate. This time I was camping so had to return to my car a couple of times, get stuff out out and lock up again. When you open the tail gate, the interior and dash board lights up. It was only two days later, went back to my car to leave. Loaded up. Car tried to start but then gave up and died. A brand new AUX battery should NOT fully discharge in 48 hours!
I had to resort to my emergency jump start battery to get her going. This works but we ended up leaving early and ruining our holiday because I did not want to risk it happening again later in the dark and probable rain. It's ridiculous that with a car packed full of batteries like the PHEV I have to carry a third and regularly fumble around under the bonnet to start her.
Purchased a handy little Lithium Ion jump start battery. Sees to work okay and just slides under the drivers seat.

 

[HHL]

. A brand new AUX battery should NOT fully discharge in 48 hours!

If an interior light stays on, it could certainly fully discharge the aux battery in 48 hours. It is not very big, can't remember exact capacity but pretty sure it is no more than 50Ah.

The noises you hear when you press start are mainly the vacuum pump for the brakes and the pump for the rear motor coolant.
There are no clutches to make noises.......

I have left mine parked for 3 weeks while we were away, it wasn't connected to the charger (I don't have the wi-fi module) and it was fine when we got back.

 

[anko]

The noises you hear when you press start are mainly the vacuum pump for the brakes and the pump for the rear motor coolant.

Don't forget power steering ;-)

 

[elm70]

Well, despite have a brand spanking new AUX battery it let me down again so back to the dealer today.
I'm suspicious there is a relationship with opening the tail gate. This time I was camping so had to return to my car a couple of times, get stuff out out and lock up again. When you open the tail gate, the interior and dash board lights up. It was only two days later, went back to my car to leave. Loaded up. Car tried to start but then gave up and died. A brand new AUX battery should NOT fully discharge in 48 hours!
I had to resort to my emergency jump start battery to get her going. This works but we ended up leaving early and ruining our holiday because I did not want to risk it happening again later in the dark and probable rain. It's ridiculous that with a car packed full of batteries like the PHEV I have to carry a third and regularly fumble around under the bonnet to start her.
Purchased a handy little Lithium Ion jump start battery. Sees to work okay and just slides under the drivers seat.

Very strange indeed ... definitely some fault around the battery, not a battery problem

What does surprise me is your "start"

My PHEV does not start the engine when I switch on the car ... instead as first thing my PHEV uses the 12kwh battery for top up the 12v battery .. so I don't get which type of failure you have

Assuming the 12v battery will be almost dead on my car .. I just need to do the first 10min without starting the ICE .. and I expect by the time my 12v battery should have enough juice for start the ICE

Additionally ... In my case ... I have a cheap Chinese 12v Car USB + Temperature + Voltage meter ... so I always know the status of the battery and as well the internal temperature .. plus and extra USB charger that never hurt .... got it for 6USD shipped .. and I'm using since ages also in my previous and other cars I own ... knowing the 12v battery state is quite a good info to have all the time available

Since I see all the time the voltage of my PHEV.. actually for me it is odd to see most (95%) of the time while I'm driving that the 12v battery is "sitting" under charge at 14.7v ..

 

[elm70]

. A brand new AUX battery should NOT fully discharge in 48 hours!

If an interior light stays on, it could certainly fully discharge the aux battery in 48 hours. It is not very big, can't remember exact capacity but pretty sure it is no more than 50Ah.

The noises you hear when you press start are mainly the vacuum pump for the brakes and the pump for the rear motor coolant.
There are no clutches to make noises.......

I have left mine parked for 3 weeks while we were away, it wasn't connected to the charger (I don't have the wi-fi module) and it was fine when we got back.

So .. the start.. is not ICE starting ...

Actually I never even notice any noise when I switch on my PHEV ... so my "pumps" and servo steering should be quite silence ... instead .. if I have AC on ... yes, this is quite loud, especially from outside the car. Anyhow .. I would expect the charge from the 12kwh battery to the AUX battery should be stronger then the power consumption for these "pumps" .. so if the car has enough juice for "start" it should not die unless ICE start is requested (which require quite some power surge)

As you ... I have left my car unused for a while .. and no issue at all ... I think somebody in the forum did left his PHEV unused for months and he did not had any issue as well ...

And yes ... the 12v AUX battery in the PHEV is quite small .. I guess is just 40Ah or less

 

[HHL]

Actually, the aux battery does not start the engine, ever!
The generator does... via the traction battery.

 

[anko]

Indeed. Very little power is needed to start the car. I have been in a situation where I had to jump 'start' my PHEV, several times (self inflicted pain). Hook up another 12v source and hit the Start button. As soon as the Ready indicator comes on (the ECUs are booted), you can unhook the other battery and your car will be fully operational.

 

[jthspace]

Where do you "hook-up" the other 12v source - under the bonnet onto the little red covered connector or in the boot onto the aux battery?

When I had to get mine "jump started" (for want of a better expression) trying to put portable battery jump leads onto the connection under the bonnet failed, the mechanic had to put ones on from the breakdown truck generator instead.

Jeff