Flat Aux battery - getting going again

[littlescrote]

Last week I had a road trip across France. I had a cool box plugged in to a socket that I'd previously fitted with a low voltage cutout device so as not to flatten the Aux battery overnight, but when I came out to the car in the cold morning the 12V Aux battery was obviously low voltage as the car wouldn't go into Ready mode and gave the dreaded "EV Sytstem Error" warning.

Somehow I'd managed not to have my USB starter pack with me, but a fellow hotel guest had one that he lent me, so I thought it would simply be a case of connecting it up to boost the 12V back again and off we go (which I've done before). However, that did not work. The car still would not go into Ready mode. Thinking that his pack may not be boosting enough voltage for boot up, we also tried jump leads from his running engine, but again no success.

I then disconnected the Aux battery briefly and tried again to turn it on with no boost but it didn't work, however I noticed that when I had been trying before disconnecting the battery, the green Ready light would come on very briefly before going off. I then disconnected the Aux battery again briefly before connecting the USB booster pack again and it worked. I guess it just needed a reset followed by a healthy voltage before booting up.

I hope someone else finds this useful in the event of a flat Aux battery. You'll get all sorts of scary EV System fault messages but they are not necessarily serious and can be reset with a simple battery disconnect. Most recovery firms would have just towed it to a Mitsubishi dealer. And always carry a booster pack.

 

[greendwarf]

Thanks for the tip - hope you enjoyed the rest of your trip - I'm jealous.

 

[JPD]

tanks for the tip of disconecting the neg post in order to reset the computer.. Here is what happened to me: I went 3 days of just driving short distances without ever charging the main battery. One cold morning ,I got in the car tried to start it would not start I and got a message of contact dealer but it never told me why. I found out it was the 12 volt battery had gone lower than critical voltage. the only solution by dealer service was : can you boost the battery? or call AAA and bring the car in for service. fortunately my son in law had a booster pack which when plugged to the red connector in fuse box open up all the system in the car. we then got in the back to have access to the battery itself disconnected the neg post and recharged the battery to 14 volts. And presto everything worked again. The problem is I still dont know why my 12 v battery went critically low. Since then I have installed a 12 v battery monitor purchased on amazon, on the battery and can check it with the App on my phone which reassure me of its condition .My outlander is a 2020 model with low mileage, the battery should not have done that, so im kind of insecure about this. The question is why my main battery system did not charge my 12 v battery everyday for 10 minutes? It has now been 2 weeks since this happened. when i charge the main battery my 12v battery charges .to a healty 12.9 v then trickel down to 12.4 what is draining the battery when parked. another thing I learned the B setting when in drive mode is at level 2 and as i understand the 12 v battery is also being charged by the B settings. I used to put my car in 0 setting all the time is it what caused my problem... but im not changing the b2 setting when in D mode anymore. I am going to ask the dealer if i have the correct software up date on my car and check if the main battery chrges my 12 v battery every day.

 

[ThudnBlundr]

The 'B' setting has no effect on the 12V battery - regen uses the motors as generators to charge the HV battery. The DC-DC converter powers the 12V systems and charges the battery as soon as the car is switched "On", and the car maintains the 12V battery whenever you are using it. AFAIK it will only charge the 12V when off as long as the car has WiFI and it is accessed; after a while it will turn off the daily charge.

 

[Stevepl11]

Last week I had a road trip across France. I had a cool box plugged in to a socket that I'd previously fitted with a low voltage cutout device so as not to flatten the Aux battery overnight, but when I came out to the car in the cold morning the 12V Aux battery was obviously low voltage as the car wouldn't go into Ready mode and gave the dreaded "EV Sytstem Error" warning.

Somehow I'd managed not to have my USB starter pack with me, but a fellow hotel guest had one that he lent me, so I thought it would simply be a case of connecting it up to boost the 12V back again and off we go (which I've done before). However, that did not work. The car still would not go into Ready mode. Thinking that his pack may not be boosting enough voltage for boot up, we also tried jump leads from his running engine, but again no success.

I then disconnected the Aux battery briefly and tried again to turn it on with no boost but it didn't work, however I noticed that when I had been trying before disconnecting the battery, the green Ready light would come on very briefly before going off. I then disconnected the Aux battery again briefly before connecting the USB booster pack again and it worked. I guess it just needed a reset followed by a healthy voltage before booting up.

I hope someone else finds this useful in the event of a flat Aux battery. You'll get all sorts of scary EV System fault messages but they are not necessarily serious and can be reset with a simple battery disconnect. Most recovery firms would have just towed it to a Mitsubishi dealer. And always carry a booster pack.

If you need to reset stuff because "reasons" try this instead of disconnecting the 12 battery negative cable, which requires a 10mm spanner and those little bastards always get lost when you need it most.
There is a fuse labelled IOD in the main fuse box. That's Ignition Off Draw. Pull that out foor a few seconds and put it back. On my 2018 model it has a big fuse puller already attached, like it's meant to be easy to do this.

 

[littlescrote]

If you need to reset stuff because "reasons" try this instead of disconnecting the 12 battery negative cable, which requires a 10mm spanner and those little bastards always get lost when you need it most.
There is a fuse labelled IOD in the main fuse box. That's Ignition Off Draw. Pull that out foor a few seconds and put it back. On my 2018 model it has a big fuse puller already attached, like it's meant to be easy to do this.

Good suggestion