Battery problems

For all electrical questions; Alternators including fitment; Light connections/wiring; Instruments; Gauges; MFA; Heater blower (not coolant related) issues etc etc.
Forum rules
Hints, tips and guides for repair and modification - the FAQ section on the main website is worth checking first for information relating to common faults and technical help. Useful posts and guides will be added to the FAQ http://www.sciroccoregister.co.uk/scirocco-faq
Post Reply
MK21800
Posts: 104
Joined: Wed Aug 03, 2011 1:41 am
fill in the right answer: 10
Location: Kingston, Surrey

Battery problems

Post by MK21800 »

Used to have a Bosch s001 battery in the rocco, started obviously going after a bit, checked it with voltmeter, only charged to 12.3v then got worse - eventually it wouldn't charge above 9v, was a dead cell according to local motor factors.

Replaced about a year ago with a nice Bosch S005 (?) - nice battery - car has been fine for about a year. Rarely driven though, probably once every week to two weeks. I haven't trickle charged the battery since I got it, relying on alternator instead.

Alternator is only a Motorola 45 amp. Replacement for old knackered alt. Fan belt is tight enough, I think.

I only have a standard stereo and nothing much to pull charge of the battery - no alarm or anything, everything standard.

Anyway, thought I'd trickle charge the battery today while in situ in the car - battery would only charge to 12.4V before charger says "maintaining".

Checked battery 10 mins later - down to 12.25 volts and holding round about there. Understand that this could be "Sulfation" after a bit of research.

Any thoughts? This battery is only a year old, is a nice S005 but already won't charge beyond 12.4V and then holds at 12.25 V?

Is this just to be expected on a car that isn't driven that often or does it sound like there's a problem? I didn't think I'd be having to get a new battery every year... do you lot find this?

Car is outside, not in a garage.


mark1gls
Posts: 3954
Joined: Thu Apr 02, 2009 9:28 pm
fill in the right answer: 10
Location: Somerset

Re: Battery problems

Post by mark1gls »

Check what the battery is getting from the alternator when the engine is running, you should see just above 14v at the battery terminals with a multi meter.

The last 2 Bosch batteries I’ve had don’t seem to be as good quality as they used to be, both only just lasted the time they are guaranteed for (S4 so 4 years)

I’m now trying a Ysasa battery as had one on the wife’s car for 14 years…


Mk1 78 Scirocco GLS 1.6 FR, weekend toy.
Mk1 88 Golf GTi cabriolet 1.8 DX. Daily drive.
Membership No. 323
mark1gls
Posts: 3954
Joined: Thu Apr 02, 2009 9:28 pm
fill in the right answer: 10
Location: Somerset

Re: Battery problems

Post by mark1gls »

I’ll have a check what my battery is sat at tomorrow, cars not moved for a couple of days and let you know what the results are…


Mk1 78 Scirocco GLS 1.6 FR, weekend toy.
Mk1 88 Golf GTi cabriolet 1.8 DX. Daily drive.
Membership No. 323
RussGLAuto
Posts: 357
Joined: Sat Jul 14, 2018 11:51 pm
fill in the right answer: 15
Location: Bourne

Re: Battery problems

Post by RussGLAuto »

Cold kills batteries. Fact. Feb is usually the coldest month of the year.

Mk21800 suggest running / charging your beloved more frequently...


Daily Driver - 2017 Volvo XC90 T8 Twin Engine - Polestar - Arctic White
Weekend Wagon - 51k 1982 Mk2 Scirocco 1.6 GL Auto - Diamond Silver
Other Half's Wagon - 2018 Mk7.5 Golf GT TSi Auto - White
Daughters Curb Scraper - 2016 Fiat 500 1.2 - White
User avatar
GT_II
Posts: 522
Joined: Thu Feb 23, 2017 11:18 pm
fill in the right answer: 15
Location: Warwickshire

Re: Battery problems

Post by GT_II »

Keeping your battery permanently connected to a maintainer like this one, designed specifically for classic cars, will keep your battery healthy:

https://accumate.co.uk/accumate.htm

Or if you select carefully from this long list, you may find a suitable one that will also de-sulphate your battery (De-sulphating uses higher voltage, so make sure your earth lead is disconnected from the battery if you need to de-sulphate, to avoid frying your car electrics):

https://accumate.co.uk/cg020001.htm


1992 VW Scirocco GT II 1.8 90PS Brilliant Black 30k
RussGLAuto
Posts: 357
Joined: Sat Jul 14, 2018 11:51 pm
fill in the right answer: 15
Location: Bourne

Re: Battery problems

Post by RussGLAuto »

:read:


Daily Driver - 2017 Volvo XC90 T8 Twin Engine - Polestar - Arctic White
Weekend Wagon - 51k 1982 Mk2 Scirocco 1.6 GL Auto - Diamond Silver
Other Half's Wagon - 2018 Mk7.5 Golf GT TSi Auto - White
Daughters Curb Scraper - 2016 Fiat 500 1.2 - White
WreckTangle
Posts: 124
Joined: Sat Dec 02, 2017 5:16 pm
fill in the right answer: 15

Re: Battery problems

Post by WreckTangle »

If it’s an S5 005 battery then that is a Silver-Calcium battery and the alternator is probably not putting out a high enough voltage to charge it properly. That means it will be perpetually running in a semi-discharged state and will sulphate quickly drastically reducing its useful life. Modern technology batteries and classic cars do not pair particularly well. A more basic battery is likely to last longer in such conditions.

Unfortunately, it is nigh on impossible these days to source a 12V lead-antimony battery which would live happily with a 14V alternator output. Modern batteries tend to need about 14.7V to start charging.

It may be possible to fit a replacement voltage regulator to the alternator to increase the output voltage but you’d need to be careful the rest of the vehicle electrics can handle it. This approach worked well for me recently on an old Volvo.

The safest approach is regularly to attach the battery to a smart charger. This will condition the battery by using the correct voltages at each stage of the charging process and then maintain it in good condition using the correct float voltage, like a trickle charger.


User avatar
GT_II
Posts: 522
Joined: Thu Feb 23, 2017 11:18 pm
fill in the right answer: 15
Location: Warwickshire

Re: Battery problems

Post by GT_II »

WreckTangle wrote: Sun Jan 30, 2022 12:47 am If it’s an S5 005 battery then that is a Silver-Calcium battery and the alternator is probably not putting out a high enough voltage to charge it properly. That means it will be perpetually running in a semi-discharged state and will sulphate quickly drastically reducing its useful life. Modern technology batteries and classic cars do not pair particularly well. A more basic battery is likely to last longer in such conditions.

Unfortunately, it is nigh on impossible these days to source a 12V lead-antimony battery which would live happily with a 14V alternator output. Modern batteries tend to need about 14.7V to start charging.

It may be possible to fit a replacement voltage regulator to the alternator to increase the output voltage but you’d need to be careful the rest of the vehicle electrics can handle it. This approach worked well for me recently on an old Volvo.

The safest approach is regularly to attach the battery to a smart charger. This will condition the battery by using the correct voltages at each stage of the charging process and then maintain it in good condition using the correct float voltage, like a trickle charger.
Very good to know - I can't find any battery seller that acknowledges and explains this issue. Some like Halfords seem honest in saying they don't sell any batteries suitable for my Scirocco Mk2. Others, including Euro Car Parts happily suggest the whole spectrum of Lead Calcium Batteries as ideal for the Scirocco Mk2.


1992 VW Scirocco GT II 1.8 90PS Brilliant Black 30k
User avatar
C 20 CCO
Posts: 258
Joined: Sat Jan 06, 2018 7:38 pm
fill in the right answer: 15
Location: Burnley, Lancashire.

Re: Battery problems

Post by C 20 CCO »

I have a Bosch s3 battery, I also swapped out my alternator for a GSF replacement about 10 years ago so it’s not original.
I don’t use my Rocco as a daily, it’s used mostly in good weather… make your own jokes 😁.

I have a Ctek 3.8 smart charger and use it to condition the battery, it copes fine. I have an alarm on the car and the battery does leech energy away if left for a period of time.
Like I say my s3 battery seems to be ok for the job.


kind regards,

Dave.

To be old and wise......
You must first be young and stupid!

Previously owned: 1984 1.6 CL in alpine white; 1986 1.6 GT in met light blue over black body kit; 1990 1.8 GT2 in silver.
Currently: 1991 GT2 in Pearl green metallic.
WreckTangle
Posts: 124
Joined: Sat Dec 02, 2017 5:16 pm
fill in the right answer: 15

Re: Battery problems

Post by WreckTangle »

I have found it very hard to find definitive information on the subject of car batteries. Manufacturers seem to obfuscate, especially in Europe and the UK. I have found better information from South African, Australian and North American websites but standards vary across the world. For example, the 063, 075, etc. size and capacity identifiers are published by the British Battery Manufacturers Society (BBMS) and are unique to the UK after-market. Also, try finding a consistent way to discover when your battery was manufactured.

As a consequence, one has to piece together the story from multiple sources and informed/misinformed debates across various car forums. I currently own five 1990s cars and just want to avoid expensive mistakes.

From the Tayna website “ Bosch's car batteries are split into 3 main groups; S3, S4 and S5. The S3 range is aimed at older cars with small engines. The S4 range is perfect for most modern vehicles with the S5 range being designed for high end, top of the range cars.” Helpful-ish, but doesn’t provide much technical information.

From the Wikipedia article on Silver-Calcium batteries “ Silver calcium batteries generally require more charging voltage (14.4 to 14.8 V) and deteriorate rapidly in vehicles which do not provide the required voltage range.”

I think virtually every 12V flooded car battery on sale in the UK will have plates doped with calcium. It is a feature of the low/zero maintenance claim. Silver-calcium (as opposed to straight calcium) does appear to be especially bad in older cars because of their lower alternator voltages.

There is virtually no benefit to a retailer to understand or inform their customers about this issue. It only really affects older cars which represent a small proportion of their trade. Modern batteries have a longer shelf-life and don’t require fiddly things like filling them with electrolyte before sale. The retailer’s liability will extend to replacing a battery once under warranty and perhaps telling the customer there is likely to be something wrong with their ancient car that’s draining the battery or not charging it properly.


User avatar
GT_II
Posts: 522
Joined: Thu Feb 23, 2017 11:18 pm
fill in the right answer: 15
Location: Warwickshire

Re: Battery problems

Post by GT_II »

WreckTangle wrote: Tue Feb 01, 2022 10:55 am I think virtually every 12V flooded car battery on sale in the UK will have plates doped with calcium. It is a feature of the low/zero maintenance claim.
This is the conclusion I have come to as well. Modern batteries seem to be very fussy about how they are charged. Apparently, on modern VW group cars, the exact part number, serial number and battery manufacturer code are supposed to be programmed into the ECU via the diagnostic system, so that the on-board battery management system provides the correct charge voltage and idle speed at any given time, tuned to the battery's technology, construction, capacity, etc. As far as I know, this only works for genuine VW batteries, which are of course not made by VW but manufactured to varying specifications by Exide, Varta, etc. This level of charge optimisation is probably why, in my experience, the OEM batteries on modern VW Group cars seem to be good for 10 years or more, although this may be partly down to the relatively easy life I give them.

This raises questions in my mind about battery optimisers on the market. They claim to be suitable for a range of different battery types, but I assume work to a standard charging algorithm, regardless of the type of battery fitted. I've asked Actimate, the brand of optimiser I use for my Scirocco battery, to confirm suitability for modern lead-calcium batteries, in terms of charging voltage, but so far no response.


1992 VW Scirocco GT II 1.8 90PS Brilliant Black 30k
Post Reply