EFB or AGM Battery ?

[gregoir]

The "intelligent" charger is cycling away. Applying an indicated 15.2V and 1.1A, last time that I looked. Then switches itself OFF and then repeats. Plug in voltmeter indicated 14.5 v when the charger was off.

I'm not sure how long to let it charge for.

[gregoir]

On 15/12/2023 at 10:15, gregoir said:

I already have the jump start pack. I bought a smart? charger a few years ago but using it on my wife's Kia just sets off the alarm. I used my Optimate battery maintainer on the Skoda via the power socket, but I note it's only intended for batteries up to 50Ah.

I have read both the Skoda Octavia manual and the Kia Picanto manual for details of battery charging. For the Skoda it is , naturally as the advice here.

The Kia manual insists that the battery must be removed first. Impractical and onerous. I'll stick with the battery jump pack when necessary. As I said before, connection of a charger sets off the alarm.

[nta16]

Doesn't the "intelligent" charger switch to maintenance mode after it has finished charging?

 

If you have or can borrow a multimeter to check the battery reading on the actual battery posts the next day after the charging has finished this will check any other digital reading from the plug-in device and give you an idea of how much the battery retains its charge with just the car parked and locked up.

 

I take a battery posts reading from unlocking the car, open the bonnet and leave the car unlocked and bonnet up for about half a hour hoping that's long enough for all the systems to go back to rest and take a reading then, or if you want straight from unlocking the car and opening the bonnet then perhaps allow for up to about or around 0.2v being used by the car.  On my wife's Fabia she has no added devices like camera(s) or other plug-ins using the electric on the car.

 

If you don't use the car I'd suggest you take another reading in two or three or more days from the last to see if there is any difference, as long as you are consistent in how you take the readings they should offer reasonable information on the battery and a bit of advanced warning of when you want/need to replace it.

 

Below VW figures for the battery state of charge -

12.7v – 100%

12.5v – 80%

12.3v – 60%

12.1v – 40%

11.9v – 20%

11.7v – 0%

 

[Warrior193]

5 hours ago, gregoir said:

The "intelligent" charger is cycling away. Applying an indicated 15.2V and 1.1A, last time that I looked. Then switches itself OFF and then repeats. Plug in voltmeter indicated 14.5 v when the charger was off.

I'm not sure how long to let it charge for.

The fact that the charger is cycling in the way you say suggests 1 of 3 things to me -

1 - The self-discharge rate is high - I.e. battery has an internal fault. or

2- There is some connected load that is triggering the cycling. or

3 - Something you are doing when you check the charger is waking up control modules on the vehicle

With a good battery and no electrical load, I'd expect the charge rate to go to zero once the battery reached full charge, then perhaps up to 100 milliamps maintenance charge. 

[nta16]

Looking back to the start of the thread (2019 fitted EFB replacement battery) and gregoir's posts I can see and agree that sorting the battery when you're not fully well is even more of a hassle than when fully well.

 

By what is put in the posts it seems like the alternator is doing its job and if the plug-in volts readings are correct or there about and the battery charger readings are correct or there about and having looked at the instruction manual - assuming (not always a good idea) the model is the ZXY - J30,  then.

 

@gregoir don't be offended as I'm just checking, could you you have perhaps set the charger to "REPAIR" "Repair Mode (18 hours)" or "CAR/TRUCK" "For big batteries (Fast Charge)" ["max. 8A"] ?

 

At +10c and below  temperature it should also be showing "Win. *" in LCD display. - https://nzgrab.com/scan/2513-1.pdf

 

[J.R.]

Are you charging it on the vehicle Gregoir?

 

As said once charged it will sit with a maintenance charge of (on my smart charger) 0.1 ampere, if the voltage drops below 12.8v it will then switch to a 0.8 amp charge, if the battery is on the car or has self discharge it will cycle between the two charge levels.

 

I had to recharge the batteries on my tractor and tipping trailer this week, I have loaned out my faster 8 amp charger so had to use the 5 amp Lidl smart charger and it was frickin slow despite the figures showing on the display initially looking optimistic.

 

The battery for the tipper hydraulic pump is the old one off my vehicle an 096 77ah 780 amp CCA, it had discharged to 11.5v trying to tip double what it should, within 30-45 minutes the display was showing 13.6v and 2 bars out of 4 (might be 5) but then it dropped to 12.4v and one bar, what was happening is that the charging current had dropped off to the 2nd stage and later would drop even further to the 3rd stage, it had got nowhere after a few hours and took overnight to fully charge, probably more than 12 hours (I slept in because of the cold!)

 

It has a good graph showing the stages once you can sort out the weird scales, there are 7 in all

 

1 - diagnostic and protection against reverse connection, can be ignored as it takes about 1 second!

 

2 - if battery is between 7.5 and 10.5 volts it does a pulsed desulphation stage, not with mine at 10.5v which is as flat as you could make a battery cranking.

 

3 - Between 10.5 and 12.8 volts it charges at the full 5 amps and from the display it is putting out 13.6v, this only lasted 1/2 and hour or so on my fully discharged battery and was a lot less in the past on partially discharged ones.

 

4 - 12.8 - 14.1 volts it drops to 3 amps and it says this takes the battery to 80% charge, this is when I saw the 2 bars drop to 1 bar and the voltage drop to 12.4v, I dont know how long it remained in this state but it showed very little progression over 3 hours before I went to bed.

 

5 - at 14.1 volts it drops to a 0.8v charge which they call absorbtion.

 

6 - at 14.4v it drops to a 0.1 amp maintenance charge.

 

7 - If despite the maintenance charge the voltage drops to 12.8v (could only be through a parasitic discharge or starting, ignition on with radio etc) then it will revert to stage 5 and cycle between that and stage 6.

 

So in reality there are only 5 distinct charging states.

 

What I have learned is that my 5 amp charger spends most of its time putting out far less than that, it does not get hot like any of my other chargers, its a good piece of kit for slow charging and hopefully recovering completely dead batteries but you will need to put another in parallel with the dead one initially if it is below 7.5v. Its ideally suited to keeping a battery on charge for long periods over winter etc or to connect permanently to a battery used to power a caravan or Chinese diesel heater.

 

It is pretty useless if you car wont start and you want to get a quick charge in it just enough to get the vehicle running.

 

The graph I found on the packaging is much more explanatory than any of the user instructions I have read for various smart chargers.

[J.R.]

To summarise the above in as few words as possible:

 

The 5 amp charger will only charge at 5 amps for maybe 30 minutes or less on anything other than a totally discharged battery

 

80% of the charging is done at only 3 amps.

 

20% of the charging is done at a piffling 0.8 amps which probably takes more time than the previous 80%

 

Someone cleverer than me could probably calculate how many hours it would take to recharge a flat 096 battery, I just know that it was a fecking long time!

 

At 80% charge it would be a lot quicker to put it on the car, start the car and get on your way to work allowing the alternator to do the rest.

Edited 18 December, 2023 by J.R.

[nta16]

Only posted as one example graph 7 stage from one example of an instruction leaflet - from a Lidl  (ULGD 5.0 C1) charger instruction leaflet. - 

 

[fabdavrav]

12 hours ago, J.R. said:

To summarise the above in as few words as possible:

 

The 5 amp charger will only charge at 5 amps for maybe 30 minutes or less on anything other than a totally discharged battery

 

80% of the charging is done at only 3 amps.

 

20% of the charging is done at a piffling 0.8 amps which probably takes more time than the previous 80%

 

Someone cleverer than me could probably calculate how many hours it would take to recharge a flat 096 battery, I just know that it was a fecking long time!

 

At 80% charge it would be a lot quicker to put it on the car, start the car and get on your way to work allowing the alternator to do the rest.

 

Easy ....if as you say 80% of the charging is done at 3A....& you have a 096 case size battery, which are usually 70Ah.....therefore 80% of 70Ah = 56Ah, divided by 3A =18.66hrs....

 

My Ctek MXS10 (which has 8 separate charging "steps") does the "bulk" charging at 14.7V at 10A..therfore it takes 5.6 hours to get it to 80%...this is why my battery, & the charger cables & the charger get warm....way more current is being applied...

Edited 19 December, 2023 by fabdavrav
Calculation corrected

[Breezy_Pete]

Unwise to let it get to such a low state of charge in the first place.

[J.R.]

12 hours ago, nta16 said:

Only posted as one example graph 7 stage from one example of an instruction leaflet - from a Lidl  (ULGD 5.0 C1) charger instruction leaflet. - 

 

 

Yes that is the graph that was printed on the cardboard case, the manual went walkies a very long time ago, I think that is my charger, it remains the only example that I have seen.

 

The manuals are normally tiny concertina folded bits of paper, tiny text mostly taken up with safety warnings and translations, the graph on the box is probably larger as I can read it but not as large as this on the computer screen, it also has contrasting colours which help.

 

The other great thing is a graph is understandable even with a dual horizontal axis and conveys simply the info that would take a long description like mine above and many of the descriptions have errors of translation or are Chinglese.

 

I knew that you would have a complete library of every battery charger manual at your fingertips 😄

[nta16]

The simple maths gives you an idea of time but doesn't allow for the variables so it takes as long as it takes and as gregoir doesn't use his car much he has the time for very long charges, if he wanted to, the car is just sitting there and it's not difficult work.

 

@fabdavravI didn't even blink at the pre-edit as I've had a few 48+ hour recharges of neighbours or friends batteries.  😄

[J.R.]

1 hour ago, Breezy_Pete said:

Unwise to let it get to such a low state of charge in the first place.

 

Absolutely but when you have struggled to achieve a 45° erection but need 60° to get satisfaction then you go all the way and to hell with the consequences 🤣

 

The voltage probably would have recovered a little but I put it on charge straight away, I was dissapointed that I had abused it too far, I should have used the hand pump at that stage but it would have taken a very long time, the motor was still turning but not with vigour, the higher it tips the less load on the ram and hydraulic pump.

 

It did however make me reflect on just how much abuse you would have to give a battery to get it low enough for the desulphation stage, the safest way would be to use the vehicles sidelights but as I have pondered before are you doing more damage by the deep discharge than the process could hope to recover?

 

I recovered my caravan battery, it was only a few months old but with zero volts (previous owner did not resolve the 13.4V power supply problem) but needed to fry it with a jumpstarter set to 24v then charge it with the same in parallel to a charged battery up to 7.5v, something did the job because after a couple of days it showed 5 bars and my electronic tester said 100% and 3 years later it still has good autonomy when the power is cut, but that was a leisure battery which are supposed to cope better with deep discharge.

 

💡💡💡I can swop the tipper trailer battery with the caravan one when I sell the caravan in the spring after spending 3 winters in it.

[Breezy_Pete]

I was referring to fabdav, but never mind. 😁

[nta16]

I generally only keep manuals of stuff I or friends and neighbours have so it took me a few minutes to remember where to look on t'net but below is a pdf of the Lidl ULGD 5.0 C1 (IAN 383685_2110 only) charger.

IAN 383685_2110.pdf

 

ETA: you have to fool it if the 12v battery is at or below 7.5v but as these things aren't that smart it's easy to do.

 

Edited 19 December, 2023 by nta16

[J.R.]

2 hours ago, fabdavrav said:

Easy ....if as you say 80% of the charging is done at 3A....& you have a 096 case size battery, which are usually 70Ah.....therefore 80% of 70Ah = 56Ah, divided by 3A =18.66hrs....

 

As I say I dont know the actual formula but yours cannot be right because using that method in addition to the 80% there would be a further 26.25 hours for the remaining 21 ampere hours (mine is 77ah). It probably would take 40 hours if the battery had zero volts but the charger will not function beneath 7.5v unless you do some bodgery, the leisure battery took several days in total.

 

I think the problem is that VAG and others say that a battery has zero SOC (state of charge) at 11.7v but they are speaking of useable charge for cranking and starting the engine at 12V.

 

There is no question that your 10 amp smart charger would be more suited to me but does it really do 80% at 10 amps or drop to a lower setting after an initial 10 amp (say 7 amp) like the above graph?

[fabdavrav]

3 hours ago, Breezy_Pete said:

Unwise to let it get to such a low state of charge in the first place.

 Mine doesn't get that low.....maybe 50%....but never flat....

 

Let me put it this way.... My battery has never been low enough to throw up fault codes or dash warning re the stop/start systems, power steering or the ABS & other systems which usually happens when you let the battery get really low...

 

I know how to look after my cars!...

Edited 19 December, 2023 by fabdavrav

[fabdavrav]

1 hour ago, J.R. said:

 

As I say I dont know the actual formula but yours cannot be right because using that method in addition to the 80% there would be a further 26.25 hours for the remaining 21 ampere hours (mine is 77ah). It probably would take 40 hours if the battery had zero volts but the charger will not function beneath 7.5v unless you do some bodgery, the leisure battery took several days in total.

 

I think the problem is that VAG and others say that a battery has zero SOC (state of charge) at 11.7v but they are speaking of useable charge for cranking and starting the engine at 12V.

 

There is no question that your 10 amp smart charger would be more suited to me but does it really do 80% at 10 amps or drop to a lower setting after an initial 10 amp (say 7 amp) like the above graph?

 

 

The calculation is correct....simple electronics calculations.....but its just hypothetical 

 

 

& yes my Ctek battery charger in its "bulk" stage (3) does charge the battery up to 80% capacity at a fixed 10A with a max voltage of 14.7........then the next stage is "absorption" (stage 4) which is at 14.7V fixed, but with a declining current.....& this gets the battery up to 100% capacity...there are 3 other stages after this of "analyse", "float" & then the long term connected "pulse" option

Edited 19 December, 2023 by fabdavrav

[nta16]

Done this for ease of reference. -

 

[gregoir]

My battery has never been low enough to prevent first time starting.

The intelligent charger has stimulated the Stop/Start system. Worked at each halt over the past two days around town. Even once with the headlights on. Looks like a success.

Thanks folks for all your "inputs".

[nta16]

56 minutes ago, gregoir said:

My battery has never been low enough to prevent first time starting.

Try never to get near this stage as then the battery is far too low and could have caused other issues and warning on your VW start/stop car, not to mention it won't be doing the battery any good - prevention is better than cure.  My advise is as much as you can when required fully charge the battery in your circumstances then you will better better and extended life out of your existing battery and its replacement.

 

Good luck.

 

[gregoir]

1 hour ago, nta16 said:

Try never to get near this stage as then the battery is far too low and could have caused other issues and warning on your VW start/stop car, not to mention it won't be doing the battery any good - prevention is better than cure.  My advise is as much as you can when required fully charge the battery in your circumstances then you will better better and extended life out of your existing battery and its replacement.

 

Good luck.

 

I've never "tried". In the past batteries have failed pretty suddenly. The worst case was my Mini 850cc. The battery was so weak it wouldn't crank the engine over. I removed one spark plug and it started. Screwed the plug back in with a running engine. It went well enough to get to the local battery store. A mark III Golf battery went from hero to zero suddenly when away from home. I called the AA out and a new battery was fitted. Other cars needed coaxing along with battery chargers. The good old days, mostly involving cold and snowy weather.

[Warrior193]

4 hours ago, gregoir said:

I've never "tried". In the past batteries have failed pretty suddenly. The worst case was my Mini 850cc. The battery was so weak it wouldn't crank the engine over. I removed one spark plug and it started. Screwed the plug back in with a running engine. It went well enough to get to the local battery store. A mark III Golf battery went from hero to zero suddenly when away from home. I called the AA out and a new battery was fitted. Other cars needed coaxing along with battery chargers. The good old days, mostly involving cold and snowy weather.

Wow, I bet that was fun getting the plug screwed back in while the engine was running!

I had to do something similar (but in reverse) when I blew the side out a piston in my Mk2 Cooper S - the engine wouldn't turn over (hydro-locked) until I removed no. 3 plug, relieving the pressure to allow a start and for me to limp the car to the next town.  

[nta16]

16 hours ago, gregoir said:

mostly involving cold and snowy weather.

Yeap, Sod's Law usually applies and it's rarely sunny or better still as you pull in to a pub car park.  But that happened to me with my 1973 Midget about seven years ago.  End of a nice few days runaround of Wales with friends in their Toyota Supra.  We were going for a light lunch and then part ways, A bit before we arrive there was a slight misfire so I said to the boss we'd have lunch and worry about it after.  Sod's Law it was the rotor arm needed a brush up and I'd decided the dissy didn't need attention at the recent service I'd done.

 

Same cars but in France a number of years earlier and jump leads were out because the ultra reliable Supra (still is at 25+ years old) wouldn't start but who'd believe it was the Midget jump starting the Supra and not the other way round.  My mate blamed the Italian battery fitted to the car when he bought it and very begrudgingly had to buy a high priced mediocre battery at the end of that day as we had to get the leads out again at the start of the car display and run.  He had to leave the engine running after going round a few times as we sat at a pavement table having lunch and then me and others going round the town, car sat running for a couple of hours in about mid twenty's heat with only the occasional blip of the accelerator, it didn't miss a beat or get warm.  If it'd been the Midget I'd have just found a slight slope to park it on and switched it off.  

Edited 20 December, 2023 by nta16

[J.R.]

I drove 500 miles on 3 cylinders after having removed a conrod and piston in an aire d'autoroute after running a big end bearing, I used a jubilee clip and plastic shim to block the oil hole in the damaged crankshaft journal.

 

It was amazing how smoothly it ran on 3 cylinders without a piston opposing compression on the 4th cylinder, someone could even sell a car like that saying it was slightly down on power, possible misfire 😄

Edited 20 December, 2023 by J.R.