Hybrid Forester - Battery Problems

[John Horner]

I bought the new Hybrid Forester mid November 2019, I’ve had the AA out 4 times to start the car, the electronics Battery goes flat after 4 days.  I bought this car as I had a diesel & didn’t use it  as much as I used to, so decided on a petrol vehicle with a larger engine, the Subaru fitted the bill, but then I started having problems with this car the dealership said that I need to drive it more, the salesman knew why I was sell my previous car. The first time I called out the AA I hadn’t driven it for about 7 days, the electronics Battery was flat, most of February the AA was called even though I managed to drive it more often, but that doesn’t seem to make any difference, , I’ve since had the AA engineer out to check it over, on his last visit, I had not used the car for 4 days on purpose so that the engineer could see if there was a problem & there was it had lost its charge, he recommended a stronger Battery which I’ve said to the garage but they just say I’ve got to drive it more, I’ve since had the AA out again & drove it to charge up the Battery, that was last Thursday, I went this morning to move it & the battery is totally flat, it doesn’t matter now until we are allowed to drive it. Your help Inn sololving this is problem would be very helpful.

[Andy831]

Probably not much help for your specific issue John but your not alone, I have a petrol 2018 model (68 plate) that I also often leave for 4 or 5 days without running, particularly at the moment given the situation with the virus, and I find that my Battery is losing charge over a period of 5 or 6 days so that the starter motor will not turn.

I am contemplating buying a portable Battery booster that I can carry around with me as a " just in case" solution.

It seems to me that there is so much electrical activity still going on while the car is switched off and I guess that just takes the edge off the Battery, compound that with 5 or 6 days of inactivity and soon that Battery is under 12v and unable to turn the engine.  

 

[Mr B]

measure the parasitic draw with vehicle locked and modules asleep .

Ideally want a logging ability meter so can see instances where a module maybe waking up and pulling power .

Anything over 60mA is too much, 35mA +- 10mA is more average .

Even if drive it more or retains just enough charge to start your Battery lifespan going be short due to discharge levels caused while inactive .

It certainly a fault, no car would ever be designed have stationary parked current draw flatten a Battery in 4 to 5 months let alone days .

Your dealers response is ignorant at best, excuse not to get involved in a known difficult to resolve issue at worst  ...

[Bozzybear]

My new Forester e-Boxer was totally flat this morning after standing for 7 days. As we can't go out, I have been running the engine for 20 minutes once a week but this morning I just got an array of flashing lights on the dash and no starter action. I put the Battery on charge for 2 hours and it then then started, so I ran it for 20 minutes on a fast idle. It's a bit of a worry as we often go on cruises (well we used to) and the car would stand for 18 days at the cruise port, this is my 7th new Subaru and I've never in 16 years had a breakdown or failure not start! 

[Mr B]

^
Welcome to the new eco era .If it inherent issue on new range it needs a recall as Battery drain in a week simply not fit for purpose, most manufacturers engineers design capacity and stationary current usage to last months, 7 days is a serious issue and I hearing many owners having drained Battery issues ...
If you want reliability and do your bit for environment older model vehicles do far better if review it in full spectrum not just tail pipe numbers .
New car from pretty much any manufacturer a waste of time and money these days unfortunately .

[Gillian]

I have the same problem with my brand new Forester Hybrid.  Bought at the end of February 2020, the problems with flat Battery started almost immediately. My mileage is low at best of times but just now with lockdown, even lower.  Had 2 failed attempts to start.  Dealer has said that if it continues he would fit a bigger Battery but he did say that after the first occassion.  He also suggested that I dont lock the car as the alarm takes power from the Battery.  Guess my insurance would love me doing that!  Only 500 miles and getting disappointed.

[DanS]

This is a common fault across the new Forester range. My new Forester (Dec 19) flattened the Battery after two weeks idle and the vehicle locked. Leaving the car unlocked has prevented Battery drain though bug I am lucky and have a secure area to park the car.  Dealer said I have to use it more often, difficult under lockdown though. A few isdues starting to emerge on these cars, in North America there is a class action over windscreens breaking easily. Watch this space!

[DanS]

New larger Battery has been applied to my hybrid Forester thanks to Stan Palmer at Carlisle. Parasitic drain believed to be caused by aftermarket security system common to all Subaru’s fitted at port of entry by the importer. So Battery drain is so common as to be considered a standard feature!

[Siluro]

23 hours ago, DanS said:

New larger battery has been applied to my hybrid Forester thanks to Stan Palmer at Carlisle. Parasitic drain believed to be caused by aftermarket security system common to all Subaru’s fitted at port of entry by the importer. So battery drain is so common as to be considered a standard feature!

But a larger Battery does not solve the issue. Just slightly allows the Battery to last another day or two. That is not a solution.

My WRX draws 0.05 amp once asleep. Quick Calulation (60/0.05)/24 = 50 Days or around 7 weeks to a flat Battery. That is for a 60aH Battery. So if you have gone to a 70aH bigger battery for example (70/0.05)/24 = 58 Days or around 8 weeks to a flat battery. The larger battery will only buy you week. Not a fix in my book.

I am trying a solar panel to reduce the drain (damage to battery as not been used for 8 weeks now) but if you have tinted windows you can forget that. You really need a 20w panel to be able to charge it effectively and that is getting on the large size and is capable of causing a fire, so needs to be regulated somehow. My 7.5w panel plugged directly to the battery has an effect but only if the sun is out, then it can keep the battery at a level. Good luck with that in the UK. AA sell 4.8w (and lower) panels which I cannot see doing much at all.

[Bozzybear]

I was under the impression that the original Battery had failed completely and not that a parasitic drain was to blame. My reasoning for this is as follows: I started the engine every week and ran it for 20 minutes, after doing this for 4 weeks, the next week the car had no charge in the Battery at all - as if the Battery had been removed! I think this indicates a faulty Battery to me?

[Siluro]

Agreed. I skimmed and was replying to DanS reply.

[DanS]

I raised the issue of a faulty Battery, the AA had suggested to me that this was the case however the dealership said that it was fine. Agreed the bigger Battery buys time and is not a ‘cure’. The dealer also suggested trying the solar panel route but it comes down to this I think, Battery drain is a common feature across the Subaru range. Could be the aftermarket alarms as suggested but Subaru UK deny anything is wrong.

[Siluro]

I would get Battery tested independantly and do as Mr B suggests and measure the draw when parked and modules have gone to sleep. Once you have approx draw you can use my calculation to work out how much time you have. 8 days is either one or both are the problem. The drain could also have caused the Battery to be damaged, so the draw is the real problem.

 

4.8 watt solar panel at best will maybe overcome normal draw as per MrB numbers. And that is if the car is in good sunlight and the windows are not tinted.

[Bozzybear]

In reply to Dan S, my dealer here in Leeds took ownership of the problem immediately and after testing the original  battery and finding it faulty, they replaced it with an upgraded Battery. I'm not convinced that the e-Boxer version that I have is more likely to flatten the Battery over time but I guess time will tell.

[SebP10]

It does sound like Bozzybear had a duff Battery...

However, it's becoming clear that new Subarus have a Battery drain issue. (Interesting to hear that a dealer believes it is the alarm / immobiliser that is fitted when imported.) From some rudimentary checks the alarm only seems to draw 4 mA (locked with key so alarm off) so the rest (above unlocked state) must be the immobiliser?

Both our cars draw 71 mA when parked and locked, For the standard 62 A Battery this will drain it in only 35 days, so it probably won't have enough "umph" to start it after only a couple of weeks.  I have bought a 4.8 W AA solar panel which does ok for us as one car can get 9 hours of sunlight at the moment (clouds permitting.)

Did anyone else get the Subaru email at the start of lockdown recommending that the Battery be disconnected if the car was to idle for a length of time? Seemed interesting to me that they would recommend that (albeit with a caveat that your insurance should be checked / informed.)

[DanS]

The immobiliser is fitted in Japan I believe. I will see how I get on with this new uprated Battery fingers crossed!

[Siluro]

A Battery in daily use and discharged by no more than 40% of its capacity should last for more than 3000 cycles and may not need replacing for up to 12 years. A Battery that is frequently heavily discharged may last no longer than 2 years.

https://www.itacanet.org/eng/elec/battery/battery.pdf

So if you are constantly draining it below 12v your damaging it and it will eventually leave you stranded. The panel will help but in winter maybe not so much,  i have yet to find out. You also got to take into account any short AtoB BtoA journeys that don't manage to put back what it took out starting both times.

 

[Jasper2447]

Our 19 plate Forester XT just let us down again. Third time in three months.  
only stood idle for two days. RAC tested Battery and found one dead cell. 
This on a car with only 8,000 miles on the clock. 
RAC test showed parasitic drain minimal, within acceptable range. 0.4 A was with door open and therefore interior light on  

Due to the bad cell, they replaced Battery (at cost to me of £130).  I’ll certainly be pursuing the dealership for this to be refunded, when they deign to pick up the phone. 
It seems that Subaru have had a very poor batch of batteries. 

[Bozzybear]

Hi Jasper2447,  This happened to our 19 plate E Boxer Forester last April after being stood for only 7 days during the first lockdown. The dealer here in Leeds fitted a new and much uprated Varta Battery the very next day, at no cost to us. So far this Battery has performed well - being stood for 2 weeks when I was in hospital in November without any problems. The dealer said this was a known problem with a batch of bad batteries. Hope this helps.

[Subarubloke]

I have a Dec 2019 registered Forester e-Boxer - already had the auxiliary Battery replaced due to going flat. - but was a prereg so been standing a few months.....

BUT - since that have had numerous other issues - randomly - stop start not working unless driven 20 miles, heated seats not coming on automatically below 10deg

AVH not working sometimes, closing drivers door can sometimes switch off heating etc.

Im picking it up tomorrow - and service manager seems confident the re-boot of all systems they have done at subarus instruction has fixed the issues.

Dealer has been very good about the whole issue with a loan car etc.

[Mr B]

^
I wouldn't be so confident, is a reason it needs reboot and that either buggy software or hardware bugging the software .
I would expect issue be back and if it is you better getting vehicle swapped or your money back unless they good enough diagnose root cause .

[jimboy]

Hi all,

Newby here.

Picking up my new E-Boxer 1st of March. Read this thread with a tad of concern naturally 🤔

Called the dealer and he confirmed me that his dealership is aware of the Battery problem. He confirmed that Subaru are aware of the problem. The dealership, he assured me, have been automatically ordering a warranty replacement uprated Battery for all new E's they sell. So mine will have it installed before I collect it.

🤞all will be well when I park it up.

Jim

 

[Bozzybear]

We had an uprated Varta Battery fitted in April and even though we've only done 2000 miles since new in Dec 2019 the problem seems to be solved.

[Jimday]

I also have had problems with a 1 year old e-boxer Forester with 4 incidents of a flat Battery in the last year, culminating in a warramty Battery replacement earlier this week. The most recent incident happened as we were on our way to have our Covid injections. Out Volkswagon van, which had not been out for 3 weeks, came to the rescue. No problem with its Battery. So Subaru have a design problem either related to Battery drainage as suggested, charging sequencing/prioritising or an underpowered battery.

J

[Bozzybear]

Hi Jimday

           I trained as a motor mechanic in the early 1970s when alternators were replacing dynamos on cars. Our E Boxer Forester has done 2800miles since new in December 2019. The problem is relatively simple, we are taking more out of the Battery than the pitifully small mileage and thus the alternator can replace. I've had heated front seats on, heated steering wheel on and on two recent occasions I sat in hospital carparks waiting for my partner to haves treatment coz I'm not allowed in under Covid rules, on these occasions I have sat listening to Amazon Music via Apple CarPlay for about an hour each time. There comes a point where the Battery does not contain enough energy to start the vehicle. The solution is to purchase a so-called "Smart Charger" As our our car is currently only used twice per week for short runs to the local  hospital I leave the smart charger connected 24/7. The problem will be solved when we can use our cars without restrictions. .Hope this helps.