The MGF Register Forums

After buying my 1996 MGF in October I spent time driving it, enjoying it and keeping an eye out for things to put right. One of the things I noticed was the lack of bulbs in the mirror along with disconnected high level break and under bonnet lights.
I put bulbs in the mirror, re-connected the high level brake light and the under bonnet light. They all work now, but the footwell lights do not and I can't figure out why - but had decided to live without them. Thanks to those on here who helped with advice on that one.
After a few weeks of MG inactivity due to other commitments I come to start up the car and all I get is a click, click. Used jump leads and the car started, moved it out of garage and back in as I didn't have time to use it. A few days later (yesterday) decided to start up go out and give the battery a charge as the sun was shining - no chance. The car will not start with jump leads and the battery is now completely flat. I can borrow a battery charger and will do but I am wondering if there is any connection between the disconnected lights I inherited - my fixing them and the battery discharging. Anybody got any ideas if this is possible, or what can be causing the battery to discharge (it looks newish), and how I can sort it out.
Roger

Hi. It may just be a coincidence & you have a bad battery. If it doesn't start if you haven't used it for a while my first suspect would be a dodgy battery.

Jump starting the car & moving it around won't charge the battery, you'd need to go for a proper drive to get it charged.

If I suspect a battery I always replace it easy to do and relatively cheap then you know it's a good one you're using.

A good battery is a first essential.
In the late 60s, I took a new Austin 1300 Countryman to live in the then Jugoslavija. I needed to travel around from Belgrade to Sarajevo, Mostar and Zadar with minus double figures at night in the winter. The car was a pain to start so I fitted an immersion heater in the lower coolant pipe with a mains timer. Final decision was to buy a 2nd battery in Klagenfurt. The battery shop had some on cheap offer. Lucas removed from new UK cars imported. The best alternative was a "Varta". Yes please.
I still replace my car batteries with "Varta" . Fortunately we have 3 cars with the same size so it is a case of "hand me downs"
They may be more expensive but with a 5+ year life, they cost half a tank of petrol or a round of drinks a year , or a 1/4 and half if you are buying a cheaper one.
Geoff.F

If the battery is at all suspect, then this cold weather will find it out. Any garage worth its salt should have a tester that can tell whether the battery is delivering of its best. The only way to be sure that there isn't a background drain on the system is to connect a battery conditioner to the car when not in use, such as an "Accumate". That will keep it topped up without overcharging.

The location of the alternator on a non a/c MGF can often lead to the drive belt not being correctly tensioned. A slipping belt can lead to failure, which could also take out the cam belt. That will cost you dear, for the sake of a few minutes maintenance. Change the belt if it's at all suspect.

Thank you all.
Looks like a new battery is the best idea then. Might try and get this one tested by the friendly local garage and they can get me the replacement if needed.

Roger

I usually use http://www.tanya.co.uk quick delivery & good price I went for a Duracell for our TF think it has 600CCA still runs down after 2 weeks if I forget to connect it to the Ctek worth getting a cheap multimeter to check alternator output.

Eurocarparts regularly have sales making their prices good.

My TF will drain the battery over 3-4 weeks if I don't use it, to the extent that I fitted a battery isolator. I always use it when I park the car up for more than a couple of days and regardless of time left standing and temperature, it has then always fired up first turn when asked. (That's undoubtedly put the mockers on it this weather ).

Battery isolator sounds a good idea - after a new battery !

Thank you for that, will investigate further.

Roger

I've got what is known as a 'Richbrook' battery Isolator. Plenty of suppliers on the web or even, I see now, Halfrauds. Relatively inexpensive and a five minute job to fit.

If you go down this route get the green version - the black has a fuse link that will drain the battery , and find a supplier who will sell you a spare knob - you never know when you might lose the original!

It's the alarm draining the battery.

flyingbanana wrote:It's the alarm draining the battery.

Could you explain more? My own car hasn't been started in around 6 weeks, but I know I can go & turn the key now & it'll burst into life.

The alarm shouldn't drain the battery after a couple of weeks, if the battery is good of course.

There are a few items that are a constant draw on the battery - not normally enormous, but add up in time - clock, fuel gauge, radio (standby/memory), alarm/BCU as you'll see a number of items like interior lights operate without needing key in the ignition.

I don't think the fuel gauge draws current when the ignition is off, other wise it would move when you were filling up.

There is a relay in the ECU that remains live for 10 minutes after ignition off, it has been known to stay open, IIRC it draws about 2 amps.

RN558 wrote:Battery isolator sounds a good idea - after a new battery !

Thank you for that, will investigate further.

Roger

It would be better to find the cause, prevention is better than cure.

James

It might be a good idea to check the alternator output too!

You need a multi-meter of some sort and you are looking for around 14V at the battery with the engine running. Any lower, except after a good long run when the charge voltage will progressively lower, shows the alternator is not doing a good job and may need to be changed.

I had my TF 120 (auto...so no bump starting!) for over 10 years and it always flattened the battery if left for 14 days or so, quicker in the winter just 10 days! I ran a waterproof external socket out from the garage to near the car and just put it on charge if I knew I was going to leave it unused for more than a couple of days. I never found what was causing it either and just lived with it.
One year we went away for nearly 3 months during the winter and both my cars were left on charge for the whole period and both started first time upon our return.

As Neil mentions above, any play car that is not used daily needs the battery to be maintained. This maintenance is achieve by using a "Float Charger" viz., a charger that switches "Off" when fully charged but also switches back "On" as required.
All older chargers continue to charge (or overcharge) until switched off.
These were replaced by chargers that switched "Off" when fully charged and stayed "Off".
Modern better (more expensive) chargers are "Float Chargers". . These are available in a variety of higher rated normal trickle or boost rates or a small compact unit (much cheaper) with a low charge rate which only tops up a battery but will not charge a dead battery. viz. the Ctek.
Choose which satisfies your needs.
We keep a normal with Float and a Cetek.
The battery loss will depend on time, the capacity and the quality of the battery.
Geoff.F

My 97 F is definitely a "play" car and certainly between now & spring it will only venture out on fine days when there's no salting been done on the roads. As a result, if I don't use it for a fortnight or so, I can expect the battery to be pretty well depleted if I don't connect it up to the accumate the day before. Annual mileage is probably around 2000 miles. I accept that that's just how it is. The battery is about 4 years old, as is the alternator.

"Float Chargers" is more commonly known as a trickle charger.

Solar chargers are quite good at maintaining charge as well.

Battery charged - started first time ! Hurray.

Battery disconnected - need to purchase a cutout switch and fit that.

Still have not solved footwell light problem but that can wait until better weather.

Roger