VW Tiguan battery charging

G;day all - Tiguan battery flat and first attempt at charging ('standard' fixed rate charger ) showed no improvement. (Direct connection to Pos and Neg terminals (NOT via power socket)) Any owners with relevant experience and/or advice, please ?

TIA

Bill

Is it clicking starter solenoid flat or no dash lights flat?

Hi Bill

I assume that the battery is ordinary - ie usual for a car (not Lithium or Edison, etc). The answer really depends on what has been happening to the battery in the last six months. If it was last charged, and worked OK, two months ago or less, then I would look for faults in your wiring, and the 'standard' charger you are using. If it has been - dare I say it ? - neglected, and has been standing in the flat (discharged) condition for weeks then it is likely to be scrap. The plates will have become coated in lead sulphate, which unfortunately does not play the games we rely on for charging and providing power. If you had a modern, more expensive (clever) charger, you might regain some charge-ability by connecting ther charger and leaving it on for 24 hours or so. This might put some (not much) life back in. If so - if it will light a headlamp bulb for a few minutes - then allow it to discharge until the bulb shows a red glimmer only, and charge up again with the clever charger for another 24 hours. Do this repeatedly for a week (or longer if you can), and you might restore the battery - at least enough to start the car - assuming that everything else is in bang-on condition - clean connections, thick wires, good earths, fresh petrol - and the first thing you should do is run down to the battery shop and buy a new battery. And get a modern charger while you are there, and use it daily.

Hope this helps - Tim

Did you disconnect the battery before attempting to charge it ? If there is something on the car that has discharged the battery & the fixed rate charger is low capacity maybe a drain could absorb the output of the charger rather than charge the battery ?

Most likely, though, is that the battery has just died (you didn't mention how old it was). I have had experience of a number of modern car batteries that just died - OK when parked up one day & dead the next morning. A replacement battery sorted the situation. A 12V lead acid starter battery allowed to discharge below around 10V is probably not going to last long even if it did manage to accept a charge - they are not designed for deep discharging.

If you do replace the battery, fully charge the new one before fitting it.

Nigel B.

Thank you all - and, yes, it is 'long in the tooth !!!

However, having, eventually, looked in the right place, I found a set of jump leads ... great joy! ... until they proved to be too short and couldn't manoeuvre close enough

So off to Wilko, new 6 metre jobs and Hey Presto, satisfactory noises. New battery on order (mega-pricey it seems)

Fingers crossed and thank you all again

Bill

These days most cars have a charging module in the battery earth lead between post and body. If you connect directly to the battery earth post, the module is by-passed, which may have some unwanted effects. So the general rule is to connect the earth lead of your charger/ jump lead to an earth point on the engine or body - a specific marked point is typically provided. Live can go directly to the battery post.

Smart chargers are not expensive any more, its worth getting one. I have never had problems leaving the battery connected while charging, either with card or bikes. I have an AGM battery in the bike and with the proper smart charger it keeps on going year after year, and that charger is also used on the car just to top up if necessary.

Leave the charger on for a very long time. My little 35 year old charger needs 20 hours to recharge the monster that lurks in my SMAX diesel.

During that time the voltage rises to 13.5 volts, less than the alternator gives, but close enough, and the current drops to 2A, which reflects the resistance in the circuit. Go by the current as the voltage doesn't vary so much. Be sure it has stabilised.

Being disconnected helps to be sure about this. A trick an AA mechanic used was to pull off the connector and put a rubber glove under it, that way he didn't have to wrestle the thick wires to ensure it was isolated from the car.

Then it will start and run OK. If the current stabilises quickly you had charge in the battery. If you have plenty of volts but low starting current then its probably the lead sulphate thing.

John H - Thank you for that ... I noted (and complied with) the restriction but hadn't realised why it was necessary !

old mart - Good point - I vaguely looked into it a year or so back but confused myself with 'float chargers' and which was best for two low mileage, intermittent use cars ... so gave up ! Time to look again, methinks

Smart chargers are not expensive any more, its worth getting one.

Indeed - and they do put in more charge than a simple charger.

But their big failing - in this case particularly - is that most won't start to charge a 12V battery that is below around 10V at the terminals. With a dead flat battery, the "smart" chargers I have come across don't recognise that a battery is connected & they won't start charging. I have resorted to connecting another good battery across one requiring charging to get a "smart" charger to see enough voltage to start it up.

The cheapy smart chargers from Aldi and Lidl are very good - while they are working. Had more than one fail on me - one in warranrty replaced without quibble, two just out of warranty that were "recycled".

Nigel B.

Thank you Nigel - I've just ordered a 10 amp unit with (apparently) selectable charge functions to deal with varying charge states - would this be a 'smart' charger, or is that something quite different ?

rgds

Bill

Before disconnecting the battery check the manual to see what in addition to the radio will lose its settings if there is no battery. It is now 'normal' to connect a small maintainer to the terminals when changing battery. Saves reprogramming the radio if nothing else,

would this be a 'smart' charger

Do you have a make/model or link for the unit you have ordered Bill ?

Smart chargers typically have the ability to select different charge profiles to suit different battery types - flooded, Gel, AGM etc. and operate 3 or 5 stage charging regimes. Some have pulse charging & maintenance functions to help with sulphated batteries & allow the charger to be left connected without risk of damage respectively. They usually have some form of digital display & mode selection buttons. A charger with an analogue meter & just a high/low charge switch would probably not be a Smart charger.

Nigel B.

Nigel - thank you, I used my deeply ingrained technical skill to select a model from the hordes available i.e. the one with 'flashy lights' and pretty colours !!

It duly arrived and plugged in. The 'flashy lights' bit generated a sequence of leds illuminating in a part circle, the little screen at the top indicating voltages etc and the lower mode annunciators indicating LiFePO4 !!! In the centre of the circle of leds is a small circular area marked 'mode' Pressing this or, indeed, pressing any of the surface 'indicators' produces nothing. The accompanying 'destruction' booklet seems to indicate that these 'functions' should be selectable ... but they aren't !

I stopped the process and 'messaged' the seller suggesting that all was not well. His reply, this morning, reads

"our charger can match the charging mode intelligently, please don't worry"

My aged logic says that seeming selection indicators which select nothing, apparent function selectors which do nothing and battery type indicator indicating the wrong battery type are signs of malfunction. Seller, apparently thinks not ... any thoughts, please ?

rgds

Bill

You usually have to have it hooked up to a battery before you can get any sense out of it at all. And if the battery is kaput, it may not recognise it and do nothing at all anyway. The only way to tell if the battery is kaput is to put it on a load tester. Standing voltage is not a reliable indicator with today's batteries. Most battery shops will do a free load test for you (and then happily sell you a replacement!)

A pic of the charger or a link to one one the net would be helpful to know what we are talking about.

LiFePO4 usually denotes a Lithium Iron Phosphate charger/battery and may not be compatible with ordinary batteries, including Lithium Ion. You would need to check what kind of battery you have in the vehicle and what the charger's destructions say about that.

Edited By Hopper on 12/11/2022 12:14:31

Thank you, Hopper. I should have mentioned that I have 'moved on' a little - the Tiguan is sorted - new battery ! and i'm now trying to charge a Berlingo. It only does very low mileage and needs an occasional boost. The battery is the original (2014) lead-acid suitable for stop/start diesels.

The charger is as below ...

When operated, the top screen shows various values, the circle of leds sequence continuously, missing out the last one and the LiFePO4 charge mode indicator remains illuminated. None of the function selectors, (including the central 'mode' point) have any effect.

The 'destructions', in common with many nowadays, are useless !

rgds

Bill

Bill

This is a Ctek brand smart charger

**LINK**

I bought one last year after the battery in my wife’s car died. The battery was only a couple of years old but the car has very little use and the battery had been left partially discharged for some time.

This charger has a few functions to try to restore a battery and can also be left connected for a car that isn’t used much. I bought after looking for recommendations on line. It seems popular with owners of classic and expensive cars.

Stuart

Thank you Stuart - the one I have is obviously similar in intended function. My concern at the moment is whether it is working properly - i.e. should the mode/function/regime indicators on the fascia be active or just decorative ?

rgds

Bill

Some newer smart chargers don't handle very flat batteries well ... I recently experienced a totally flat battery (left the car door ajar ... my newer "smart" battery charger wouldn't touch it (too dead!), but my older "dumb" charger (which just pumps 13-whatever volts into it without thinking) worked and brought it back to life.

I have the same one. Bought to perk up the battery on my Forester e-boxer.

I have 2 Yuasa 12V 10Ah batteries in the shed, long time ( 2-3 years ) since used or charged.

One was showing a terminal voltage of ( IIRC ) some 4-ish volts and the other about 5-ish.

The CTEK seems to have resurrected both after a fairly long performance both went into "7".

Just put one on about 2 hours ago and it's back up. ( in some time < 2 hours, didn't watch over it ).

The other is now hooked up. Charging. See what transpires.

D.

Edited By Dave Daniels on 12/11/2022 16:01:42