Battery preservation tips?

[Wino]

You only have to pop the bonnet up and listen to how long the process goes through even by just unlocking the car it can go on for a good 10 minutes.

[unofix]

26 minutes ago, TomsFocus said:

  I mentioned on another thread that I've considered a solar charger left in a South facing screen to keep the batteries topped up (I know they won't provide a high charge for a low battery) but wouldn't even know where to start with finding out which one would provide what I need at a reasonable initial cost.

This is about the minimum that would actually work and possibly keep an already charged battery in a good topped up condition.

https://www.amazon.co.uk/Powered-Battery-Charger-Caravan-Package/dp/B07P7C6QLD/ref=asc_df_B07P7C6QLD/?tag=googshopuk-21&linkCode=df0&hvadid=232037057466&hvpos=&hvnetw=g&hvrand=4501223981137824647&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1006688&hvtargid=pla-782175424793&psc=1

[alexp999]

I went camping for 2 nights over Easter, so you are in and out of the car without moving it. Everytime you unlock the car to get something you can hear the relays clicking, despite being at a good state of charge and a 40 min drive before parking up, by the second day, it had already shut off the keyless entry and was not booting the sync screen just a message about saving power. It's crazy how much power modern cars use just being unlocked as they boot up all their modules.

[TomsFocus]

1 hour ago, unofix said:

This is about the minimum that would actually work and possibly keep an already charged battery in a good topped up condition.

https://www.amazon.co.uk/Powered-Battery-Charger-Caravan-Package/dp/B07P7C6QLD/ref=asc_df_B07P7C6QLD/?tag=googshopuk-21&linkCode=df0&hvadid=232037057466&hvpos=&hvnetw=g&hvrand=4501223981137824647&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1006688&hvtargid=pla-782175424793&psc=1

Thanks Dave, seems like a reasonable price (can be had £25 elsewhere too) so I may get one of those.

Would you risk plugging it in via OBD rather than using the croc clips?

[Eric Bloodaxe]

I've been looking into one of those solar chargers too. I have similar issues to Alex when up at our caravan. Makes you wonder why modern cars which are hard on batteries don't have something like this built in (I know some EVs do), rather than some of the other electrical bits that many of us find less than useful.

[Wino]

2 hours ago, TomsFocus said:

Thanks Dave, seems like a reasonable price (can be had £25 elsewhere too) so I may get one of those.

Would you risk plugging it in via OBD rather than using the croc clips?

Don't bother with it Tom, had one last year and was very hit n miss.

Sold it on just before xmas.

[unofix]

32 minutes ago, Wino said:

Don't bother with it Tom, had one last year and was very hit n miss.

I agree that most are a total waste of time. You need at least a 20 watt but ideally something with a higher rate, 30 or even 40W would be good but then physical size starts to become an issue. They are of no use at charging a flat battery but in decent sunlight a 20 watt unit will produce a sufficient high enough voltage that it will provide around a 1 Amp charging current. They in no way come anywhere close to the claims all these panels make, but it will help slow down the discharge of a battery on a vehicle not used for weeks at a time.

In answer to Tom's question, I'd be happy to plug in to the OBD port. The solar panel plug only has two wires and they go directly to the supply pins. Not much to go wrong, just don't expect a miracle 😉

 

[StephenFord]

1 hour ago, unofix said:

I agree that most are a total waste of time. You need at least a 20 watt but ideally something with a higher rate, 30 or even 40W would be good but then physical size starts to become an issue. 

I have 2 x solar 'chargers' the most powerful, a 'Sealey' is 8w, it's pretty much useless. Bought it to keep my previous car on a trickle charge, would have been better off attaching my own hands to the battery and using my inbuilt electrical charge! It did light up the green charging LED, I reckon that's where all the power went!

[Tizer]

Just for info regarding the amount of power required to start. My 1.5 3 Cylinder petrol shows minus 127 Amps during cranking, but the scale in FORScan only goes to -127 so it will be more than that. I shudder to think what your car draws @unofix.

If I get a chance tomorrow I will do some Data Logging on a short run for anyone interested. It's easier for me because I have the phone app than some of the rest of you.

 

[Freddy42]

A fascinating thread; hope the OP benefited.

[NortonSS]

I have a maypole charger, I know the positive clip fits straight onto the positive terminal of the battery ,does the negative lead fit on the negative terminal (by-passing the state of charge gizmo) or attach onto to the earth bond inside the bonnet.

Many Thanks.

[StephenFord]

4 minutes ago, NortonSS said:

I have a maypole charger, I know the positive clip fits straight onto the positive terminal of the battery ,does the negative lead fit on the negative terminal (by-passing the state of charge gizmo) or attach onto to the earth bond inside the bonnet.

Many Thanks.

Attach it to the bodywork of the car - if you attach it directly to the battery -ve termnal, the BMS (battery monitoring sensor) will not realise the battery has been charged as you'll be bypassing it!

[Tizer]

For anyone interested here are the results of a 15 minute run I did this morning while logging the charging system. You can come to your own conclusions, I will put mine at the end, and it may dispel some of the myths that I keep seeing. 

This was on my Mk4 Focus and may be different on other cars, especially older ones, and may be specific to the conditions of my car at the time and maybe my charging system or FORScan were not working correctly so don't take it as gospel without doing your own checks. The battery SOC was a poor 57% which is nowhere near the 80% target and I'm sure the charging system would have behaved differently if it was above its target. 

If anyone has any Data that is different I would be happy to hear about it.

This was taken after a 10 minute run and a 15 minute rest while I was at the shops so the engine was quite warm and the battery would have shown quite a high Voltage from the run.

Before starting the engine and about 30 seconds after switching on the Ignition (time to set FORScan up), FORScan was showing a -9 Amp Current Draw, 11.7 Volts and 56% SOC, although this changed to 57% in less than a minute after starting.

During Cranking the Current went to -127 Amps, this is as far as the scale in FORScan goes so it would have been less and the Voltage at the BCM went to 8.7 Volts briefly. The Current went up quickly after starting and the Voltage more  lineally and after 11 seconds the Voltage was 14.8, where it more or less stayed throughout the journey (14.7 to 14.8). The current at 11 seconds was 16Amps although it peaked at 21 a few seconds before all as this Screenshot.

 

The Current then gradually went down to : after 1 Minute to 8A, 2 Minutes 6A then after 3 Minutes the Current settled to 2 Amps average. It was pulsing rhythmically between 0 and 4. The Voltage stayed the same throughout at 14.8, occasionally pulsing to 14.7. After 10 Minutes the Current was averaging 1 Amp and the SOC was 58%, up from its true 57%.

All these Current and Voltage readings did not change whether the car was moving or not. Just before the end of the journey I stopped with the Engine running and switched the Heated Windscreen on and, the following all happened within about 2 Seconds, the Current went to -12 then up to 11 Amps. The Voltage to 13.9 then back to 14.8 and both these  readings went back to where they were before after this 2 Second blip.

When I switched off after the journey the Current was -7 Amps and the Voltage 12.5 Volts.

My conclusions for my car are that as far as changing is concerned it does not  make any difference how fast you are travelling or whether you have any accessories on within reason except perhaps during the first few seconds or minutes and the Alternator is well up to the job and a 15 Minute run adds little to your battery.

As for your query @TomsFocus, the jury is still out. The Alternator does put back the initial charge quickly but then the charging rate is very low. If a Smart Charger gives a constant 4 Amps under the conditions I described then it should provide a quicker charge in the long term but I don't know where the cut off point is and don't know when the Smart Charger starts reducing its Current.

I would be interested to hear the results and conclusions if anyone has done something similar to their car.

  

[unofix]

Excellent report John @Tizer 👍

You have confirmed many points regarding the charging behavior, and despite your SOC being low at 56 - 57% the charging circuit made little attempt to recharge the battery quickly which in some ways is a little surprising but on the other-hand satisfies my concerns as to just how high the voltage would go and for how long.

As I mentioned earlier the only way to get the battery to draw more current and hence recharge quicker, is to increase the charging voltage. That's not too much of a problem when the battery is disconnected from the car and a charging voltage of say 20 volts could be used, automatically reducing as the battery SOC increases.

 

[Tizer]

3 minutes ago, unofix said:

despite your SOC being low at 56 - 57% the charging circuit made little attempt to recharge the battery quickly

Yes, I have always known that a 1/2 hour blast up the Motorway does not put much charge onto a battery.

Another thing I did not mention is that was all on the Conventional Charging Cycle, on these cars they sometimes switch to either Slow Regeneration, Fast Regeneration or battery Refresh cycles and the Current and Voltage are different, usually one is higher and the other is lower but I can't remember what way round it is for the different Charging Cycles.

[TomsFocus]

11 hours ago, Tizer said:

As for your query @TomsFocus, the jury is still out. The Alternator does put back the initial charge quickly but then the charging rate is very low. If a Smart Charger gives a constant 4 Amps under the conditions I described then it should provide a quicker charge in the long term but I don't know where the cut off point is and don't know when the Smart Charger starts reducing its Current.

Thanks John.  Very interesting results and I've certainly learnt a lot from this thread!  (Despite having trained as both a spark and a vehicle tech 10 years ago!)

 

The Smart charger works in reverse to the cars system.  It starts with a 1 amp charge, and only increases in 1amp increments if the charge rate isn't as high as it expects (checks roughly every 20 mins from memory). 

I have plugged the Mk4 into the powerbank this morning as it happens, expecting to fully drain it within 5 hours, then charge the powerbank on low rate electric at 2pm, and do the same tomorrow to finish off both the Mk4 & the Golf.  (On a mission to get both cars fully charged this weekend if I can.)  What is odd is that the Maypole registered 12.0v when plugged in.  But when I checked with the multimeter on Weds, the battery only showed 11.6v.  Any idea why that might be?  Didn't have a spare hand to take the multimeter down this morning, or the effort to go back down with it, but I am intrigued as to that difference.

Have you tried any free apps with your Forscan adapter at all?  I do have the adapter which I could easily chuck in my pocket this afternoon, but I grudge paying £6 for an app I'll rarely use with limited functionality, especially after 6+ years of using the free Forscan app on laptop!

[unofix]

1 hour ago, TomsFocus said:

What is odd is that the Maypole registered 12.0v when plugged in.  But when I checked with the multimeter on Weds, the battery only showed 11.6v.  Any idea why that might be? 

My thoughts would be calibration errors. I don't expect that the maypoles meter will be that precise and even your multimeter will have a slight error. You are only looking at a difference of 0.4V, and even how good a connect is when measuring can have an effect.

[Tizer]

1 hour ago, TomsFocus said:

  What is odd is that the Maypole registered 12.0v when plugged in.  But when I checked with the multimeter on Weds, the battery only showed 11.6v.  Any idea why that might be?

The only thing I can think of is that there was a lot more Current draw when you had the Meter on it. I have a Clamp Meter and if I was to open my car now and check the Current it would be high and take at about a long time to get to get even below 1 Amp so the Voltage would be showing low as well in these circumstances. The only times I have check my Voltage with a Meter is after the car has been opened for a long time and it is usually 12.4-12.5.

I've had my Lidl special Smart Charger for almost 3 years now but never had to use it yet but I did have another look at the instructions and it may be the same as your one. After some conditioning it slowly ramps up the charge to a maximum of 3.8 Amps until 80% SOC then drops it until full, so running the car may in fact be better quicker, who knows.

The only free App that I have tried is the free Torque one and it is very basic, I believe that you keep needing to buy addons to get any meaningful functionality. I cant see any of the other free or even paid for ones to be anything other than very basic.

The FORScan one does everything that the Laptop one does other than Configuration and Programming, Output Control Mode and a very few service Functions. The ABS service Bleed is greyed out on my phone App but not on the Laptop. You do need a good Adaptor though but I believe that you can use a Wired on with an OTG adaptor if your phone has that functionality and maybe not all Wired ones will work.

A note for anyone reading this about the Phone App, it has been removed from the IOS Play Store because Apple will not pay FORScan because of the sanctions, so it nay disappear from Google as well. 

[unofix]

2 hours ago, Tizer said:

A note for anyone reading this about the Phone App, it has been removed from the IOS Play Store because Apple will not pay FORScan because of the sanctions, so it nay disappear from Google as well. 

Hi @Tizer just bought and downloaded FORScan Lite form Google play store this morning.

What dongle are you using with yours ?

I've just looked at the WiFi unit from TunnelRat electronics but I see it is still using a switch. I was hoping to be able to get an auto switching dongle.

[Tizer]

I have the OBDLINK MX, bluetooth, the older one before the MX+. Mine is probably faster than a lot of wired ones but the downside is that it cost almost £100 at the time and is more expensive now but paid for itself many times over. I believe that the same people who make the vLinker do a WIFI one for a more reasonable price, it won't be a quick as mine but for diagnostics and simple service Procedures it does not matter. The OBDLINK WIFI one does not work very well and is now not recommended.

FORScan now gives a one time warning in the App as well if it thinks the Adaptor is not good enough.

If you can get hold of an OTG Adaptor try your wired one, your Sony phone should support OTG. If you have a look in the App settings under Connection Type it lists what type of Adaptors should work.

If you do get set up with the App you will be surprised by how convenient and good it is and a bonus is if you keep the Adaptor in the car you'll be glad the first time the check engine light comes on when you are away from home. The Dashboard is better than the Laptop version because the dials move in the App but the Graph is not as good because of the size of the phone screen.

[TomsFocus]

What's the best way to get the most accurate voltage reading on the Mk4?  Will be using the multimeter directly across the battery as the Maypole readings seem strange.  (12pm was at 15v with 4 bars...I unlocked it and it dropped to 13v with 2 bars!?  2pm, still locked, it's at 13.5v with 2 bars.  Hasn't taken much charge from the powerbank, only around half as much as the same amount of time yesterday.  )

I will have to unlock it again to open the bonnet.   Should I then leave it a while with the bonnet up and unlocked?  5 minutes?  15 minutes?  Should I cycle ignition or engine on at all?

[Wino]

18 minutes ago, TomsFocus said:

What's the best way to get the most accurate voltage reading on the Mk4?  Will be using the multimeter directly across the battery as the Maypole readings seem strange.  (12pm was at 15v with 4 bars...I unlocked it and it dropped to 13v with 2 bars!?  2pm, still locked, it's at 13.5v with 2 bars.  Hasn't taken much charge from the powerbank, only around half as much as the same amount of time yesterday.  )

I will have to unlock it again to open the bonnet.   Should I then leave it a while with the bonnet up and unlocked?  5 minutes?  15 minutes?  Should I cycle ignition or engine on at all?

I believe that's normal Tom.

The maypole seems to give the battery an initial charge the drops back to condition and trickle charge it. Well that's the way I've understood it.

Maypole man himself ( @StephenFord ) will probably have a better answer.

[TomsFocus]

Yeah, but it does mean you can't get an accurate reading from it.  And the bars don't make any sense at all...they don't seem to bear any relation to the amount of charge.  It's alright if you can leave it plugged in overnight until it's completely done and on green, but not much use if you can only give it a few hours here and there.  So I will have to test with the he multimeter to see what the actual charge is now.  But that needs to be done when it's not munching through current just because the door's been unlocked.

Must admit, the Golf voltage works exactly as I'd expect...  Minor 'blip' of a few tenths of a volt as the car unlocks, then back to the original voltage within seconds.  

[StephenFord]

3 minutes ago, TomsFocus said:

Yeah, but it does mean you can't get an accurate reading from it.  And the bars don't make any sense at all...

 

I've tested the Maypole voltage reading with my multimeter, and with me, they are entirely in sync. I do admit though that your observation on the 'bouncing bars' are hard to decipher, though I'm fortunate in having a driveway so can just leave it as long as it takes. I'm in the habit now of doing my mums car and mine on a monthly basis, and it never takes more than an hour, though initially when I started my charging regime, 8 to10 hours wasn't uncommon.

[Tizer]

1 hour ago, TomsFocus said:

What's the best way to get the most accurate voltage reading on the Mk4?  Will be using the multimeter directly across the battery as the Maypole readings seem strange.  (12pm was at 15v with 4 bars...I unlocked it and it dropped to 13v with 2 bars!?  2pm, still locked, it's at 13.5v with 2 bars.  Hasn't taken much charge from the powerbank, only around half as much as the same amount of time yesterday.  )

I will have to unlock it again to open the bonnet.   Should I then leave it a while with the bonnet up and unlocked?  5 minutes?  15 minutes?  Should I cycle ignition or engine on at all?

With  these cars, unless there is something wrong with mine, then I would say it would be at least 1/2 hour before the current draw settles down to its sleeping state whether it is locked or open and in that time frame it should not matter if the Ignition has been on or off before the time as long as nothing is opened or switched on during the wait. Not very convenient if not in a garage or driveway. 

A purist might say that if the Engine has been run or charged before the time wait then you should maybe switch the lights or something on for a short time for Lab conditions accurate reading but I think that is overkill.