Message Forums

My car battery is the sealed type that has a little spy hole with a green light in it. Until yesterday the green light was clearly visible but today it seems to have gone out

Does this mean the battery is dying? The car still starts and everything seems to work ok but I don't want to be dumped powerless on the motorway one day.

no green dot means it needs charging if its yellow its flat

Thanks...there's no dot at all at the moment. The window is just black. I took the car for a drive today and checked it again when I got back to see if it had come back on but it is still black. The car starts and runs fine with no warning lights anywhere so a bit of a mystery.

I have a good raport with my local main dealer so I will pop it in there on Monday and hopefully they will check it out for me.

Thanks for the advice.

Quote: Originally posted by trottster on 15/3/2014

---

The green is for when they are in storage from New not when they are in service

---

Thanks for that. The car is coming up for 5 years old but I have only had it for a year. I don't know how old the battery is but the green light has been showing all year until today. I don't drive a lot so the car sits around doing nothing for 2-3 days at a time sometimes which might cause some drain on the battery.

I have looked online and some people say the battery needs changing and some say they have run batteries for 10 years after the green light went out so it's a bit confusing.

I think there was a comment about it being there to give an indication of the state of the battery while in storage so hopefully the battery is fine.

I suppose if it was an ordinary battery without a light I wouldn't know any difference and wouldn't be worrying about it, would I - lol

The official line...

The Magic Eye® (originally designed by motorcraft) that is used in batteries provides 4 stages of indication, they are:
1. Green: battery is charged and the acid level is good.
2. Yellow: Battery is partially dis-charged and the acid level is good. Re-charge the battery or drive the vehicle.
3. Red: Battery is dis-charged and the acid level is good. Charge the battery.
4. Clear and bright: Acid level is low!!! Add distilled water if possible. If not, change out the battery. Do not charge or jump start the battery!!!

While the Magic Eye® is only located in one cell, it is still quite accurate for indicating the state of charge of all cells as they are within 95% of the same condition. If there is a catastrophic failure such as an internal short circuit, the battery would be bad, but the eye would still show green as the density of the acid is still technically correct.

Thanks rabb_uk,

If I have understood that correctly...if there is no colour showing in the window (just looks black) and the battery is sealed and cannot be refilled, I need a new battery?

Quote: Originally posted by Hacksaw Bob on 15/3/2014

---

Think it means your battery needs a new LED (or whatever that Magic Eye® thingy is)!     

---

That could well be the case - lol - but I will get it properly checked out on Monday. Although my car is only a micra it is a top of the range and has electric everything so needs a good battery.

I have done more research online and there are so many different opinions that I am coming to the conclusion that unless the electrics start playing up or the car gets difficult to start then the battery is probably fine...after all, not all batteries have magic eyes.

I have just remembered that I have a voltmeter somewhere so I can check the battery charge later today although that won't tell me the state of the cells of course.

It probably doesn't help that my micra is the type which has sloping back headlights and water drips down between the headlights and the bonnet straight onto the negative terminal of the battery. Water also runs off the bulkhead below the windscreen directly into the cups where the shock absorber nuts are. These cups are usually full of water but surprisingly aren't showing any signs of rust yet.

This model is no longer produced and it doesn't surprise me...really bad design faults around the engine compartment area.

I contacted the garage this morning and they said not to worry too much about the green light as they are not reliable. They said if I took the car in they would test the battery for me. This they did and apparently the battery is holding a good charge of 12.4v but could do with charging up. The reason is that the car isn't usually driven enough to keep the battery fully charged.

I was told that if I drove the car for about two hours with the headlights on, that would cause the battery to be charged up. Doesn't sound right to me but I have no plans to drive for two hours anyway...probably cheaper to buy a new battery than use two hours of fuel

So...result is to forget the green light and keep driving but check the voltage now and then and if it starts getting too low charge it up...the garage said they would do that for free. However, the battery is probably 5 years old so may need replacing soon anyway.