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total volts loss

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taschereau Tony Austin
eccleshall, staffordshire, UK   GBR
Hi, I would very much appreciate for other peoples view, ideas or opinions over the following: -

My car has been garaged now since October with the battery on a trickle charger to maintain it and allow the car to be periodically started until the spring as I would normally carry out.

Everything has been OK, however, in case this incident is connected when I started the car as usual a couple of weeks ago, the starter system laboured as though the battery was low in charge. After a short time it did start and I ran it for a while as usual. Assuming the battery was suffering I gave it a boost charge over night and then attached the trickle charge unit. (could this have been the start of a loose earth)

Now to last Thursday evening when I went to the garage as usual - key in ignition - wait while pump fills the carbs - then turn the key, a few clicks and then dead. I assumed the it was the battery, but checking, it was well over 13 volts, however there was no life in the car, no ignition light, no horn etc. and at this point disappointedly closed the garage door not even replacing the trickle charge.

I've had other things to do since and have grand children here the early part of the week so will not get back into the garage until probably next week. I have some ideas to process but I thought I would post the events on here and see if you can offer your thoughts or ideas which might reinforce my own or maybe provide an option I hadn't considered.

Many thanks in advance.

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JMA Avatar
JMA Silver Member John Anderson
Donvale, Victoria, Australia   AUS
Tony,

It sounds like a dead cell, the best way to test the battery is to do a load test.

The 13 volts you're seeing is fine at rest but when the battery is under load, like when cranking the engine, you will find that it will drop considerably.

John

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Billm Avatar
Billm Bill Masquelier
Santee, CA, USA   USA
I would remove,clean and reattach the battery connections before I did anything else!
Billm

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Steve B Avatar
Steve B Silver Member Steve Brannan
Weeki Wachee, FL, USA   USA
I will just add that if you have an ammeter wired in the car, or a cut-off switch, make sure they are both still corrected. I had an early MGB that lost power at midnight on a dark corner. Very scary when all of the lights went out. One side of the ammeter connection had come off....
Steve

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mgcbrian Brian Hutchison
Hampshire, UK   GBR
1968 MG MGC
1969 MG MGC
1969 MG MGC ~ For Sale ! ~
Sounds to me like a bad earth either on the battery or the attachment to the battery box or both.

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lgorg Avatar
lgorg Larry Gorg
Renton, WA, USA   USA
1966 MG MGB "Robbie"
I am with John, it may be a dead cell. Do not know if your batteries are like the ones here in NA, with caps over each cell, but check the water level in all cells. Many years ago, I owned a Studebaker Commander which also had the same symptoms. Lots of juice when sitting, but turn the key, and you have a precipitous drop to almost nothing. The dead cell serves as a sink of power from the other two cells, so you get nothing coming out.

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kirks-auto Platinum Member Robert Kirk
Davenport, IA, USA   USA
All reasonable answers posted, battery connections, dead cell.



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Snowberry C Chris A
Havant, Hampshire, UK   GBR
1969 MG MGC
Hi,
Could be where the lead from the battery connects to the solenoid on the starter motor. That was the issue with a friend's MGB. 50 years of corrosion on the terminals. Unbolted, cleaned, re-attached and all was fine.
Regards
Chris

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chormy Avatar
chormy Gold Member Shaun Holmes
Norwich, Norfolk, UK   GBR
1963 MG MGB MkI "3330 PE"
1964 MG MGB MkI
1967 MG MGB GT "BABE"
1967 MG MGC    & more
Check the old link between chassis and engine , this braided link suffered


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flyingjohn Avatar
flyingjohn John L
Kent, Maidstone, UK   GBR
1969 MG MGC GT "RTE 935G"
Tony - is it possible you connected the trickle charger round the wrong way and have knackered the battery and reversed its polarity. I have seen it before where + and minus look reversed to a voltmeter but it will not sustain any current.

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PFT-000 Bruce Ibbotson
Brisbane, Australia   AUS
1968 MG MGC GT "The Truck"
1968 MG MGC GT "The Truck"
Tony,

All the above apply but it looks like the battery has finally cried "Enough".

In my MGB, long ago. I drove home from a long day out, rolled the car out to wash it next day and then nothing no start, not even the Radio would work. The battery was not old in this car as it was my daily driver at the time, but one of the cells must have gone open circuit internally after switch off from the day before. This is not common but has happened to me.

Down here in OZ I have used Century Yuasa Batteries with great results but they can still die without any warning, my current DIN44LMF 12 Volt battery is almost 8 years old and I got the first warning last Sunday that it's time to replace this excellent battery, too many months over the last 3 years on the trickle charger with little use due to full major engine /transmission rebuild then strip and full repaint of the the external body. I don't think modern batteries are intended to sit on trickle chargers for extended periods.

I assume you have a 12 Volt battery if not consider replacing the obsolete 6 volt designs with a modern 12 Volt battery which will supply much greater CCA's than the old 6's in Series and get rid of 2 connectors and 2 feet of cable [8 ft back to 6 feet total] for much better starter performance.
I have been advised that modern batteries can die with no warning at all, good today nothing next day.

For Aussie readers:

Century-Yuasa have a better battery than the 370 CCA DIN44LMF, (same size) available which here retails for AUD189-00 (10% Seniors discount available at Battery World a Century-Yuasa Franchise) that has 410 CCA [Cold Cranking Amps] with a 40 month warranty. For OZ owners this is battery type.NS40ZLSX MF.

Bruce.

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tab a Thon Basom
central, KS, USA   USA
With "well over 13v" how can you have a bad cell?

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taschereau Tony Austin
eccleshall, staffordshire, UK   GBR
Half term is now over and the kids have gone back to their parents, so I can get back into the garage and consider all of the above.

Many thanks to all of you for your contribution, whereby I find it necessary to say that receiving comments from everyone has made it feel like a very close community.

If possible I will let you know the outcome.


Tony

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PETE W Sussex Peter H
Ansty, West Sussex, UK   GBR
In reply to # 3896923 by tab a With "well over 13v" how can you have a bad cell?


The explanation I had is that it is because under load and the intense heat this creates, there is a separation of the connection(s) between the cells. When not under load the connections make contact. I think a good battery should be able to maintain c9.5/10.5v for about 30 secs under load but I have never tested that.

Good luck Tony!

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tab a Thon Basom
central, KS, USA   USA
Might be theoretically possible but I'd guess it's pretty rare. I'd also think 'all that heat' would probably sever that wonky connection quickly.

In my experience an open cell gives you basically 0 volts, and one shorted cell close to 10v.

Most commonly though, all the cells are knackered and voltage can be anywhere between 0 and 12.

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