Battery advice for low mileage driver

[rom007]

Having just had my completely dead LV battery replaced in my 4yo Mk4 Jazz, I'm looking for advice on battery care.

My Jazz is parked in the communal car park of my retirement block so no access to power. East Scotland so can be cold; surrounded by trees etc so little solar available in winter. 2000 miles per year, very unevenly spread; likely to decrease. I'd not driven at all for eight weeks so flat battery was perhaps not completely unexpected, but dead battery was a bit of a surprise.

I am interested in (a) not finding my LV battery is flat when I'm in a hurry (eg taking myself or a neighbour to a medical appointment); (b) not finding my LV battery is dead and needs replaced (ditto, as this week); and (c) taking care of my HV battery.

I have a voltage display thing plugged in to the lighter but the Honda/AA guy said that doesn't show the LV battery voltage, the HV takes over when you power the car on. Yes/no?

The manual says drive for 30 mins every 3mo to maintain the HV battery. Do y'all agree? And what kind of driving ? - must it be >50mph, for example ?

Is there anything I, a non-enthusiast, can do to detect the imminent failure of the LV battery ? Or should I simply plan to replace the LV battery pre-emptively in 4 years time ? (Honda/AA charged me £140 for supply and fit a Bosch).

I'm not keen on driving an extra 1000 miles a year just to maintain the new LV battery's warranty eligibility.

To keep the LV battery charged do I really just sit in the car, powered on, for an hour, once a fortnight, reading or whatever ?! Winter and summer ? Still, better than having to find somewhere around Edinburgh I can drive for 30 mins at >50mph in the winter !

I've seen mention of NOCO jump starters, charging packs, finding a local mechanic who will run a battery health test (Western Honda now levy a minimum £160 diagnostic charge for *anything*), or buying myself a battery health tester.

Any knowledge and experience which you can collectively bring to bear will be much appreciated !

Thanks in anticipation ...

Walter
PS my flat is too far from my car for the key to be draining the battery; and I have my dashcam's "smart parking" mode switched off

[RA273]

may I propose two suggestions :
1) just do the 30 minutes every 3 months, speed doesn't matter, the engine has to charge the HV battery, which in its turn charges the LV battery, and to be sure make it an hour.
The required distance will be a lot less than your stated 1000 miles and it saves you all the fuss of buying extra equipment, having worries and more.
And as we all know it is no punishment to drive around in a Jazz  .

2) trade in the Jazz for a petrol car, in all modern hybrid cars the 12V battery is the weak point.
In your situation there  seems to be no decent solution other than suggestion 1).
 

[Bristol_Crosstar]

Really with such a low mileage you would be better off with a small EV provided there is a charging point nearby. My wife has a Seat Mii electric, it also has a small 12v battery as well as the large one but the small battery gets charged at the same time as the large battery so it would work for you. Secondhand cars like my wife's can be picked up for under £10K.

Back to the Jazz, if you buy a battery tester from Amazon (eg https://www.amazon.co.uk/s?k=car+battery+tester&crid=7XCVHMIWMZI8&sprefix=car+battery+tester%2Caps%2C133&ref=nb_sb_noss_1) and attach the leads to the battery terminals you can get an accurate voltage. Regarding driving for a longer journey every 3 months it doesn't have to be at a particular speed although being stuck in city traffic probably doesn't count.

[Kremmen]

TBH I don't think every 3 months is often enough

I'd say every month

[Lord Voltermore]

Your driving pattern and low mileage are bad news for any car. Not just battery but rusted brakes  etc.etc   
Even a conventional petrol engine car , with a larger 12v battery needed to crank start its engine  typically now have  computer and other systems  running 24/7  even when parked,. Their  drain on the battery may be low but its relentless and  they can go flat much sooner than cars did a few years ago.  Maybe after only a few weeks. Less if the car only gets short infrequent journeys.

A fully electric car is not necessarily a solution. You  may still have the worry of  will it be charged enough to reach my appointment destination. And you still have the problem of maybe driving to a charging station, and waiting a long time while it charges.   

Hybrids have small 12v batteries, but it doesnt crank the engine.  So sitting on the drive with the engine running might indeed add some charge to the 12v battery ,because you dont also need to replace the charged used to start the engine.  .

But as others say   running it on the driveway is not sufficient  to refresh the High Voltage battery which needs to run through cycles of being charged, and discharge in ev mode. Only possible by driving  or  high tech expensive charging equipment beyond the scope and price for home users.  Every 3 months or less.

If you have a voltmeter that plugs into the lighter socket  it will show the resting voltage for about a second after you press the power button. Long enough to monitor it if you are waiting for it.  Once the engine starts the voltage will raise to about 14.4 volts or so charging voltage. But only a few seconds of this is enough to change the voltage reading once the engine stops. (at least temporarily. )  So the results can be deceptive. And how do you interpret them.       This morning my 2 year old mk4 read 12.0v before the engine started. A lower figure than I would like and less than is typically quoted on line for a charged lead acid battery.  After just a few seconds with the engine running I switched off.  The resting battery now read 12.4 volts.  Still  not great.      

I once left my 2021 car about 8 weeks unattended in January and february  with a  small solar charger attached.   This did give a very  small positive charge   despite the season. But it was in Kent which has longer  winter daylight hours than Scotland.   Mine plugged into the obdll diagnostic port in the drivers footwell. Not an easy stretch .A larger panel, wired for easier connect/disconnect  might partially solve your problem.   
 
Sorry to be blunt  but if you cant incorporate the occasional reasonably long drive  into your routine , (even if you need to schedule reminders on the calendar )   your car will suffer. And cost more in repairs and replacments than any petrol used.   

[Downsizer]

Obviously, I don’t know your circumstances, but with such a low mileage and reducing in future, it would make economic sense to sell the 4/year-old  Jazz and spend the money on taxis and if necessary the occasional car hire.

[ColinS]

Obviously, I don’t know your circumstances, but with such a low mileage and reducing in future, it would make economic sense to sell the 4/year-old  Jazz and spend the money on taxis and if necessary the occasional car hire.

My brother did just that and was quids in.

[Kremmen]

Just what I did

I was doing about 5 to 10 miles a month and on a regular CTEK so I sold up

Not missed it one bit

[rom007]

Thanks for your input, everyone !

I think for me the takeaways are :

a) every time I'm going to need my car, the day before, check it's alive

b) every month, on the way to one of my supermarket click & collects or similar, divert for half an hour at reasonable speed along the bypass (hahahaha) or M8 if necessary

c) if health issues repeatedly prevent this, as they have done for the past 8 weeks, then (1) £140 for the occasional replacement battery will be a minor cost of ill health and (2) it'll tip the balance towards ditching the car

d) don't spend money on battery gadgets (*); put the money towards replacing my new battery pre-emptively after four years

>> sell

But I like my Jazz 

More seriously, it's arguable that if I didn't have a car I'd see much less of my adult offsprogs, who steadfastly refuse to drive / learn even as they approach 40. Even if it's just a quick run to IKEA.

But your collective point is well taken. My Jazz is suboptimal and a luxury.

>> hire car

Before buying the Jazz I spent some months on a determined effort to make Enterprise Car Club work for me (along with my free bus pass). But it seemed every hire there was a new stressful time-wasting problem (EV not charging, damage not recorded in app, boot full of forgotten stuff so unusable, etc etc). Plus to be honest I'm not comfortable/confident in unfamiliar cars.

>> taxis

Taxis maybe, Ubers no. I've had Ubers cancel as they pulled up at my door, when I had booked them to get to medical appointments.

>> EV etc etc

No charging point anywhere near. Very wedded to automatic now. Not keen on second hand - last time I tried second hand it was less than a year old from a franchise dealer - and I returned it a month later for a full refund.

(*) one exception : a bluetooth battery monitor permanently installed seems on balance a good idea - but a quick web rummage yielded only models which were discontinued, or had serious privacy concerns, or were intended for boats and camper vans. Thoughts ?

Again, thanks everyone, for helping clarify my thinking !

Regards
W

[Bristol_Crosstar]

We've had our EV or five years now and one of the great advantages is they don't mind short journeys (my wife does less than 1000 miles annually). If you get a smaller model, with a small battery, it won't take long to charge at any charging station (probably 20 minutes for an 80% charge) and you will only need to do that every 2 or 3 weeks given your low mileage, also the lack of range isn't an issue if you're only travelling a few miles (our car has an official range of 160 miles and is good for 140 in summer, 120 in winter).

[Pine]

I had the flat 12v battery problem on my Toyota Corolla until I adopted this Procedure:
Put the car in Ready mode.
Switch off everything electrical. 
Remove the mechanical key from the fob. 
Leave the fob in the car, get out and lock the car with the mechanical key.
Leave the car for 30 - 60 mins.  The HV battery will charge the 12v battery. If the HV battery gets low the engine will start to charge the HV battery.  Depending on the charge in the HV battery the engine would start 2 or 3 times in an hour running for about 3 mins each time.
Never had a problem after doing this every couple of weeks.
I assume the same procedure would work on the Jazz.

I have had my Jazz since March and haven't had a battery problem yet.

[TonyTorque]

Your plan sounds sensible. One thing worth knowing on the hybrid Jazz is that the 12V battery only gets charged while the car is in Ready mode, so a monthly half hour drive does more good than a quick start in the car park. A cheap battery monitor that plugs into the 12V socket, or a simple multimeter check, will tell you if it drops below about 12.4V at rest before it becomes a problem. If you ever do get access to a socket, a small smart maintainer is the easiest fix, but with no power nearby the regular drive is the way to go.

[jonhd]

@rom007 - just checking you do the following when you park-up:

1) Double lock (i.e. press the lock button on the keyfob *twice*)
2) Hold the keyfob's lock & unlock buttons down, together, for 5 secs. (until the LED in the keyfob flashes rapidly)

1) Puts as much of the car's electronics to 'sleep' as possible.
2) Disables the keyfob <> car communications - be careful to not accidentally press one of the fob buttons, as that fully re-enables the comms. (Disabling the keyfob <> car comms also prolongs the life of the keyfob battery.)

[rom007]

Again, thanks everyone for your contributions

@jonhd, This is interesting - I can't find any reference to either of these tactics in the Owner's Guide - where do I look for other tricks and treats like this ?

[ColinB]

@rom007 - just checking you do the following when you park-up:

1) Double lock (i.e. press the lock button on the keyfob *twice*)
2) Hold the keyfob's lock & unlock buttons down, together, for 5 secs. (until the LED in the keyfob flashes rapidly)

1) Puts as much of the car's electronics to 'sleep' as possible.
2) Disables the keyfob <> car communications - be careful to not accidentally press one of the fob buttons, as that fully re-enables the comms. (Disabling the keyfob <> car comms also prolongs the life of the keyfob battery.)

Sorry, but this doesn't sound like it'll have any useful effect on the car battery (although admittedly I have no personal knowledge of the MK4 or indeed any contactless lock system).

I can understand that shutting down the key fob can be useful, eg in preventing relay theft and extending the life of the fob battery. But I don't see how it affects the car's 12v battery. Surely the car is constantly "listening" for nearby keys; if it wasn't, then reactivating the key wouldn't work because the car wouldn't "hear" it. And that "listening" will be one of the systems that stays live when the car is turned off, and will be contributing to the parasitic drain on the 12v battery.