It's been a while ............

 

Has anyone tried any other option for a new battery than the original (096) AGM type?

 

Guess who's got a flat battery ............🙄

Have you tried charging it with an external charger???

 

Cannot comment on the AGM battery but I have had a Bosch S5 008 on my Mk2 for ten years now........

 

I use a solar charger on it if it is stood doing nowt tho. And give it a proper charge every now and then if very cold / freezing weather.

29 minutes ago, Tilt said:

Have you tried charging it with an external charger???

 

Cannot comment on the AGM battery but I have had a Bosch S5 008 on my Mk2 for ten years now........

 

I use a solar charger on it if it is stood doing nowt tho. And give it a proper charge every now and then if very cold / freezing weather.

Yep, external smart charger was connected - but something was not right - I suspect a 'Pike' issue, in that it's been left for 3 months with the plug not properly connected.

 

Is your Mk ll 'Start-Stop' equipped - as per my Mk lll ?

 

I am not a fan of AGM batteries, having had problems with them, a short life and just not performing as advertised.  I understand some manufacturers are not fitting AGMs to Start-Stop vehicles any longer - because of the problems.  I was looking for an alternative, eg:  an EFB variety which are more than capable of 'Start-Stop' loadings. 

 

The other thing I don't know the answer to is if the charging system is properly configured for anything other than AGM - or even correctly set up for AGMs.  There is a difference but it's possible both options could be covered.

2 minutes ago, CityScout said:

 

Is your Mk ll 'Start-Stop' equipped - as per my Mk lll ?

 

Thankfully, no.

I think it would be disabled / turned off if it was, anyway.

 

Yes, I do believe (note I say believe) the battery type requires coding, or possibly just re-coding, if a different type is used.

 

It is usually fairly quiet on here at weekends so you may get more replies in the week............ 

You may find that a good full charge followed by long (I would say a minimum of 3 days) maintenance/float charge will restore your battery to reasonable condition, AGM batteries withstand being deeply discharged far more than other types.

 

If fully discharged, you may have to restart the charge a few times before the battery finally starts to accept the charge. Depends on how smart your smart charger is and what it can do.

 

Changing a battery even with the same type on a car with stop/start requires recoding, to reset parameters in the battery management system. Otherwise it may think you still have the same tired or end of life battery and will manage charge appropriately.

 

https://www.yuasa.co.uk/info/technical/automotive-battery-operating-states-lifespan-replacement-conditions/

 

Presumably you are aware of how to connect a charger, the negative lead must be connected to the chassis tab and NOT the battery terminal. To stop the battery management getting confused.

 

 

Thanks for the link.  That looks awfully like the underbonnet of my car ........

 

3 hours on the smart charger has done nothing.  Time to dig out the big charger and if that doesn't work, it's jump leads and spare battery.

It looks likely it's going to need a new battery, so my quest is to try and avoid AGMs if possible and reasonable.  Resetting the battery management system is the next issue, ie, who can do it?

I could with my scan tool - but that is in Spain at the moment .........🙄

Under 7.5 volts and the smart chargers will not start the charge, above 7.5v but below 11v (or so) they go into a pulse mode to try and regenerate the battery.

 

If you battery is under 7.5v it will have suffered damage and will never be 100% but you will be able to start the charge on the smart charger if you charge it in parallel with another battery as long as it is not equally discharged.

Well under 7.5 volts.  It was 2.96 volts - no I didn't miss the figure '1' off the front.  🙄

 

It's now on the bench, first with a big old fully charged battery paralled to it, and a bespoke de-sulphating pulse generator - plus a very basic 12 volt, unregulated charger across it as well.  It came up to 9 volts in an hour, so the big battery was taken off and so far the voltage is up to 10 volts off charge, 13.9 on charge.  Nothing ventured, nothing gained.  I'll see what it's like in the morning - but it will be replaced.  It has its MOT on Tuesday, so as long as I can get the warning lights out on the dash and it passes, I'll be happy.

Hindsight is a wonderful thing.  It had sounded a bit reluctant to start before it was laid up, despite being on a smart charger.  I think the 3 months neglect has finished off what was already a fairly terminal battery.

I recently bought a caravan with a 12v PSU problem, it had a brand new huge capacity leisure battery but it was only showing a couple of millivolts, none of the chargers could put anything into it including a huge trolley mounted charger/starter unit. No long slow low charges were going to cut it with this baby no matter how many times the phrase is repeated.

 

So as a last resort I did a do not try this at home attempt, I connected it to the starter/charger pack and held down the "Start" button, normally this should only be done with a cranking engine, I held it until I judged it was just shy of blowing the thermal overload trip, let it cool for one minute and repeated, I did this maybe 5 or 6 times.

 

Then I found that the battery was showing 1 volt but dropping quickly so using that charger on its maximum setting of I think 25 or maybe 40 amps I charged it and left it on overnight, the next day my electronic tetser showed it had 50% life.

 

I powered the caravan with it without the PSU, I was living in the van, and did 3 or more discharge to 11v then full current recharges, I think this charger was putting in 16.9v initially.

 

After that it was showing 85% life on the tester. Then I fitted a universal 30 amp PSU and adjusted it to the 13.89v level of the old one which kept the battery float charged.

 

It was disconnected a couple of weeks ago still showing 85% life, the proof of the pudding will be how it is when I get back there in another couple of weeks.

 

So even a completely dead battery can regain a good amount of its capacity, granted the demand on a leisure battery is different to that of cranking for a car battery but you might be in luck.

Just a thought:  Have you tried one of the pulse chargers?  I've had considerable success with one, albeit made by an electronics wizard 15 years ago, rather than a £15 Chinese built clone.  They do work - but must NOT be left connected too long.

I've just checked it and by coincidence, it was showing 13.89 volts.  Upon disconnecting the charger it settled spot on 12 volts after 10 minutes, although I suspect it would drop lower if left.  The acid test (no pun intended) will come tomorrow morning when I put it back on the car and try and start it.  If it's stuffed, the voltage will drop too far to be of any use when the key is turned and it sees the starter motor load.

I think the same will apply to your caravan battery.  As soon as it sees a serious load, it might object.

Caravan battery was fine, I ran on that alone for the first week before I chose and recieved a universal PSU, the lighting alone (20 amp halogen spotlights) were drawing most of the 30 amps, then there is the pressurised water system pump, the fan that pushes circulates the hot air from the gas fire around the heating ducts etc etc.

 

I have a really good electronic battery tester where you program in the batterys CCA, whether its EN or another measure and it calculates the remaining CCA and then expresses that as a percentage of battery life remaining (its not a proportional measure) it was showing 85% after having given it the good news with the boost starter and the autonomy using the battery validated it.

 

I have a pulse charger but they need a minimum voltage of 7.5v or they shut down.

 

20 Halogen downlight/spotlight bulbs have now all been changed for LEDs.

Now up to 12.2 volts after being left off charge for 3 hours.  Back on again, with the pulse unit.  Here's hoping ...........

The weather is really foul right now, so I'll leave it going until tomorrow morning and see what it gets up to, then try refitting it.

 

Slightly off-topic and not to teach Granny to suck eggs:

I've used and owned motorhomes for over 40 years and thought I knew a bit about batteries.  We got a very unpleasant surprise recently when the habitation battery on our (relatively recently acquired) motorhome exploded - with a bang like a bomb had gone off.  Fortunately it didn't catch fire but there was acid everywhere.  It was a good quality, Varta proper leisure battery.  I didn't know it's history, other than there had been electrical problems with the charging system that I cured.  It appears that abuse in a previous life had damaged the battery and eventually it suffered an internal short.  Hydrogen and oxygen, even in a fully sealed battery, make a good bomb!

The only clue I ever got (hindsight is a wonderful thing) is that it dropped its voltage to 10+ volts for no real reason a couple of days before and it gave almost subliminal flashes of a high charge rate the next morning - so quick you said to yourself "Did I really see that?"

I sourced a new battery intending to collect and fit it when we moved at the end of the week.

It exploded the next day and blew the top clean off:

 

 

even though it was strapped over the top and onto the floor with two 1" wide webbing straps - which it snapped.  The photo doesn't do the carnage justice.

I had to lift a 37Kg bucket of acid out from under a seat and get it outside without spilling any more.

Same desire about sucking eggs....................

 

It looks to me from the photo that the red transportation bungs have not been removed from the battery breather vents.

 

Harder to see from the camera angle but the casing looks bowed between the internal supports, that is a sure sign of overheating from too high a charging voltage and if the vents are blocked the resultant pressure will fracture the top joint as yours has, its a designed in safety feature.

 

Mind you the snapped straps does sound more like an explosion.

 

Have you checked the charging current  have you carefully inspected the casing for signs of bulging? My neighbours caravan had the same PSU and when his failed it was putting 69 volts into the battery which was fortunately vented.

 

I would hate to see your new battery go the same way, did you remove the transportation plugs?

 

They were still in the new but dead battery on my caravan.

No probs.  The red bit is a snapped off one of two vent adapters that attached pipes that went out to atmosphere.  It was the battery that was fitted when we bought the motorhome.  The charger is OK and has been watched like a hawk ever since.  There is a comprehensive display for battery capacity, voltage and charge/discharge current.  The casing was fine before the bang and the casing of the new one is OK too.  It was quite literally like a shotgun going off next to you when it exploded.

I'm fairly certain it was an internal short igniting the gas.  The new battery, a Yuasa, is fully sealed.  No vents.  Both the mains and solar chargers are IUoU profile.

 

Edited 20 February, 20224 yr by CityScout
mistake

Well, by some miracle it seems to have achieved an at rest voltage (after two hours off charge) of 12.8 volts.  I'm thinking it was the bespoke pulse charger that has helped it.  The guy who built it was/is(?) an electronics wizard who built stuff for solar charging systems and aircraft batteries - but I can't find any reference to his business now.

Apart from the usual alarm screeching at me 'til I cycled the locks, it started immediately.

TPMS, ASR/ABS and one other (memory fail) lights stayed on, plus it warned Start/Stop was disabled.  25 metres down the drive twice put them all out, the TPMS was the last to go.

MOT in the morning, so the charger is staying on there 'til it goes for that, then back on again until the new battery arrives - a Start/Stop capable Varta EFB.

Just got to get it coded at some stage, sooner rather than later, if the rumours are correct.

All MQB platform cars with the eco stop start (auto engine shut off) require recoding....& AGMs are fine, not had any problems with mine (so far) since I installed it in Jan 2015...

 

All relevant info in the first post in my thread here:-

 

How to retro-fit a bigger capacity battery to a Mk7 Golf | GOLFMK7 - VW GTI MKVII Forum / VW Golf R Forum / VW Golf MKVII Forum

Thanks very much for the link.  Excellent.  Just the answers I needed. 👍

 

To be perfectly candid, I have had more than my fair share of AGM problems, they are never as good as claimed and very vulnerable to deep discharge damage.  That and heat damage from either an external source, or internally from heavy loading is their Achilles heel ........ as well as the price.  They all seem to base the reason for fitting them on an AGM being capable of 30% more cycles - but they cost on average 30% more (like-for-like by manufacturer).  Given that, my unfortunate experience and their well documented shortcomings, I'll stick with EFB, I think.

Age will get my battery long before Start/Stop cycles.  I do very little town driving.  😀

Do you use the start/stop system, or habitually switch it off?

I tend to use it.

On 20/02/2022 at 15:52, CityScout said:

Now up to 12.2 volts after being left off charge for 3 hours.  Back on again, with the pulse unit.  Here's hoping ...........

The weather is really foul right now, so I'll leave it going until tomorrow morning and see what it gets up to, then try refitting it.

 

Slightly off-topic and not to teach Granny to suck eggs:

I've used and owned motorhomes for over 40 years and thought I knew a bit about batteries.  We got a very unpleasant surprise recently when the habitation battery on our (relatively recently acquired) motorhome exploded - with a bang like a bomb had gone off.  Fortunately it didn't catch fire but there was acid everywhere.  It was a good quality, Varta proper leisure battery.  I didn't know it's history, other than there had been electrical problems with the charging system that I cured.  It appears that abuse in a previous life had damaged the battery and eventually it suffered an internal short.  Hydrogen and oxygen, even in a fully sealed battery, make a good bomb!

The only clue I ever got (hindsight is a wonderful thing) is that it dropped its voltage to 10+ volts for no real reason a couple of days before and it gave almost subliminal flashes of a high charge rate the next morning - so quick you said to yourself "Did I really see that?"

I sourced a new battery intending to collect and fit it when we moved at the end of the week.

It exploded the next day and blew the top clean off:

 

 

even though it was strapped over the top and onto the floor with two 1" wide webbing straps - which it snapped.  The photo doesn't do the carnage justice.

I had to lift a 37Kg bucket of acid out from under a seat and get it outside without spilling any more.

Wet filled batteries detonate after a lot of deep cyclic discharging/recharging. They lose water on frequent aggressive recharge phase through splitting it into hydrogen/ oxygen gas and venting some of it instead of recombining back to water on a more gentle charge. There will be tide lines inside the casing above the plates indicating this has taken place. 

 

Once the acid level drops below the top of the plate packs, a spark can jump in the air space between adjacent plates usually when an electrical load is applied lifting the lid off.

 

Frequently seen this on industrial generators with acid sprayed everywhere inside the shipping containers. 

@BigEjit, detonation doesn't sound like a common thing in passenger cars?

Edited 5 March, 20224 yr by Pete_Ex-Wino

It isn't common but by no means unknown, especially on older vehicles.  Modern vehicles tend to have better control of the charging systems, the older systems just whacked 14.4 volts and varying amounts of current into the battery without much control.  The result was boiled off electrolyte, causing the above mentioned catastrophe.

Sealed batteries (as was the one that went bang) are not immune to gross overcharging and don't allow the electrolyte to be checked, so the problem is still there - but hidden.

In my case the whole charging and distribution system (a Schaudt unit in a motorhome) was eventually found to have been butchered by the 'repair' done for the previous owner, after a fault, probably in the 3-way fridge, damaged some wiring and the internals of the Schaudt unit.  It looks like his 'workaround' cooked the battery over a couple of years and the rest is history - plus a lot of extra laundry.😰

 

Anyhow!  Back to the original question ..................

 

By some miracle, the pulse-charge 'repair' I did on the battery has held up for now, probably because it's being driven regularly - but it is staggering that a battery that showed under 3 volts has come back to that extent.  I've got to lay the credit at the feet of the very clever guy who designed my pulse generator.  Sadly, I can't find any reference to his business, so maybe folded, or given up.

I have a new EFB battery to fit  but I'm uncertain that the current charging regime it has for an AGM will not harm the new battery, so unless someone knows otherwise, I'll wait until I can recode it before I fit it.

 

1 hour ago, Pete_Ex-Wino said:

@BigEjit, detonation doesn't sound like a common thing in passenger cars?

Generally it isn't but the same battery tech is used in other non automotive applications with far less regulated maintenance available from vehicle use leading to consequential damage if not controlled manually.

 

16 minutes ago, CityScout said:

Anyhow!  Back to the original question ..................

 

By some miracle, the pulse-charge 'repair' I did on the battery has held up for now, probably because it's being driven regularly - but it is staggering that a battery that showed under 3 volts has come back to that extent.  I've got to lay the credit at the feet of the very clever guy who designed my pulse generator.  Sadly, I can't find any reference to his business, so maybe folded, or given up.

I have a new EFB battery to fit  but I'm uncertain that the current charging regime it has for an AGM will not harm the new battery, so unless someone knows otherwise, I'll wait until I can recode it before I fit it.

 

 

Its interesting you have picked an EFB instead of sticking with AGM but understandable if you have experienced issues on batteries you have had from new and know the history of.

 

From the lab testing i have seen, AGM do stand up to cycling and deep discharge events far better than any other tech type except Optima spirals. Optima Deep Cycle spiral batteries are built to take more abuse and use essentially the same materials as AGM, only the construction method is different. EFB is midway between SLI flooded and AGM with performance to match its position.

 

AGM allow for a more agressive charging/discharge strategy than EFB or flooded so the EFB will be worked harder on AGM charging profiles. By how much is it different..? Don't know with out comparing software mapping profiles side by side.

45 minutes ago, CityScout said:

It isn't common but by no means unknown, especially on older vehicles.  Modern vehicles tend to have better control of the charging systems, the older systems just whacked 14.4 volts and varying amounts of current into the battery without much control.  The result was boiled off electrolyte, causing the above mentioned catastrophe.

Sealed batteries (as was the one that went bang) are not immune to gross overcharging and don't allow the electrolyte to be checked, so the problem is still there - but hidden.

In my case the whole charging and distribution system (a Schaudt unit in a motorhome) was eventually found to have been butchered by the 'repair' done for the previous owner, after a fault, probably in the 3-way fridge, damaged some wiring and the internals of the Schaudt unit.  It looks like his 'workaround' cooked the battery over a couple of years and the rest is history - plus a lot of extra laundry.😰

 

Anyhow!  Back to the original question ..................

 

By some miracle, the pulse-charge 'repair' I did on the battery has held up for now, probably because it's being driven regularly - but it is staggering that a battery that showed under 3 volts has come back to that extent.  I've got to lay the credit at the feet of the very clever guy who designed my pulse generator.  Sadly, I can't find any reference to his business, so maybe folded, or given up.

I have a new EFB battery to fit  but I'm uncertain that the current charging regime it has for an AGM will not harm the new battery, so unless someone knows otherwise, I'll wait until I can recode it before I fit it.

 

When you get it recoded you can change it to EFB from Fleece. 

14 minutes ago, BigEjit said:

From the lab testing i have seen, AGM do stand up to cycling and deep discharge events far better than any other tech type except Optima spirals. Optima Deep Cycle spiral batteries are built to take more abuse and use essentially the same materials as AGM, only the construction method is different. EFB is midway between SLI flooded and AGM with performance to match its position.

 

AGM allow for a more agressive charging/discharge strategy than EFB or flooded so the EFB will be worked harder on AGM charging profiles. By how much is it different..? Don't know with out comparing software mapping profiles side by side.

I'm afraid that has NOT been my experience with AGMs.  Apart from my less than wonderful encounters with them, if you look at the cost-benefit based on manufacturer's predicted Start-Stop cycles, £-for-£ compared to something like an EFB of the same quality, AGMs don't add up.

The Scout is a basic Start-Stop system, so for now I'll stick with EFBs  😀

It's more the Law of Sod than anything else that my kit is not here to help recode it when the battery decides to quit.