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MG MGB Technical - MGB Battery Replacement

I have just taken ownership of a non-working 74 GT. I have been told that it just needs a new battery and that I can use a Mazda 12v battery to replace the 2 X 6v ones currently being used.

Can anyone advise on what model of Mazda battery I should get, or any other model? Also are there any other tips before I start the changeover?

Thanks,
Colin
C F Coles

Have a look in the archives. There is a wealth of info here on what batteries fit etc.
S Coulson

Colin

http://www.mgcars.org.uk/MG_Elec-Tech/conversion.html

http://www.mgb-stuff.org.uk/

Halfords have a selection 063?
another poss Varta Silver battery 43ah and 480 CCA.

Paul
Paul Wiley

In my 69 roadster I use a Sears Diehard WeatherHandler
group 26R part#30027.
Dana Wilson

Colin, use a group 26 or 26R battery. Dimensionally this will fit in the battery box. Be sure to get top mounted terminals. Also as a tip use the felt anti-corrosion washers before fitting connections.
Dan H.
Dan Hanson

The battery is an 063 as Puul says. Go to your local LS UK (Lucas) outlet for this. It will fit in the nearside battery bay tilting it at 45% to lower it in. You will either have to flatten the old locators for the 6v battery or make a support packer. You will also have to acquire a battery clamp and two suitable clamp rods.
Electrical copnnections are however vitally important. Remove the connection from the end of the cable from the starter. Acquire a length of starter cable from LS and join the two using a collar type joint (from LS. Durite I think) The collar joint comes complete with a length of heat shrink insulation which must be used. This is vitally important to avoid a fire risk.

Then lead the end of this through to the LH battery box next to the +ve terminal and cut off. Fit a new +ve battery connector to this wire.
Obtain a -ve battery post connector and bolt this to a new braid earth strap about 9" long bolting the other end of this to a hole suitably drilled in the battery box.

Job done.
Iain MacKintosh

Sorry Colin, Wasn't paying attention. Didn't realize you were in the UK. See Paul Wileys' response.
Dan H.
Dan Hanson

Paul,

Taking a measuring tape and measure the size of one of the battery bays. Take the measurements to Halfords and buy the biggest battery that will fit. Bare in mind clearences for the terminals under the metal plate.

This is ten times simpler than finding an 063 or 26 or 26R or whatever.

Andrew
Andrew H

Andrew,

You don't have to do all this. The 063 is the battery. All the work has been done for you. That's what this bulletin board is all about. There is always someone who has done this before.

Iain
Iain MacKintosh

Thanks to all for your speedy help.

Now, where's that cheque book?

COlin
Colin Coles

If it currently (sure there is a joke somewhere in there trying to get out) has twin 6v batteries you will need to move the ground strap from the left-hand box to the right. Make sure this has a good tight connection to shiny metal on the box, there may be a bolt-hole in a similar location to the other box. Make sure you know which way round to connect the battery i.e. +ve to the main cable running forwards and -ve to ground. If there are no batteries at present connect the main cable to the battery +ve and connect an analogue voltmeter on its 12v scale between the -ve post and ground. If this shows 12v there is some load on the battery, you need to determine what it is as it could be a big one which will create a large spark when you connect the ground strap. The normal reverse leakage of the alternator diodes will normally show as a few volts on the meter, with the alternator unplugged this should drop to zero. Make sure doors and boot are closed and hence courtesy lights off, and everything else switched off. With a non-runner or after a rewire I connect a high-wattage bulb in place of the ground strap, like an old headlamp bulb with both filaments connected in parallel, and turn on each circuit in turn. Most circuits will cause some glow from the bulb, full brightness indicates a big load which could be a short which might damage wiring. Attempting to spin the engine on the starter *will* generate a large load so can't be checked until you do it for real. Connect the battery ground strap last.
Paul Hunt

Thanks again ... job done in the way Paul Hunt suggested, using the box behind the driver so that the +ive lead did not need to be extended and indeed there was a hole already there for the -ive ground.

Of course it did not start first time. But once I had found that I had accidently disconnected the petrol pump leads, which are at the bottom of the battery well, then it fired second turn. Amazing after 10 months or so!

Colin Coles

As a matter of interest I too changed form twin 6v to single 12v battery. I used the Halfords 063 but I read on this BBS that Halfords where going to stop stocking this model.

Anyway the reason for my posting is to suggest an easy way to secure the battery. First of all place some plastic in the bottom of the tray you are going to use about 20mm thickness should do. But I would suggest you try the installation of the battery before purchasing the plastic you need, as your battery may be different to one I purchased some years ago.

Next step is to purchase two clip straps similar to the ones used on rucksacks, (you now the forked clipped ones). Thread these around the battery and the tray clip together and adjust so that they are tightened. No drilling or anything!
Cecil Kimber

According to an article in Road and Track last summer, the Miata (MX5) uses a specially designed battery which has proven to have an incredibly long life-span; some dealers were reporting that 10 year old Miatas were still driving around on the original battery. I assume that they are 1: Expensive, and 2: probably have a programmed charge. Yup and yup..... but a buck thirty is cheap if you only have to buy one....

I just read a San Diego Miata club newsletter on the subject and have pirated the first few paragraphs:
http://www.sandiegomiataclub.org/SDMC/Garage/Battery_Update.html

The Miata Battery - More Choices Than Ever Before
Every Miata manufactured and sent to the U.S. since 1989 has been factory equipped with a special battery. I (author) wrote an article for the SAN DIEGO MIATA CLUB NEWS in 1997 that detailed the stock Miata battery and an alternative aftermarket replacement (SDMC News, Volume 2, Number 6). This article is available on the SDMC Web site and on Miata.net in their respective Garage sections.

Since that article was written, changes have occurred in the area of batteries for the Miata. The OEM (original equipment) battery is a product of Panasonic. This battery caused confusion early in the sales of the Miata, since it did not require service like a standard car battery. In addition, mechanics who tried to "quick charge" it found out they quickly ruined it.

At the same time, Miata owners were finding out this is one great little battery. Usually a car battery will last, on average, 36 months. If you take good care of it, and live in a temperate climate, 48 months might be expected. The Panasonic has a demonstrated average life of 6 years (72 months) and there are continuing reports of original Miata batteries still going strong beyond the 10th year of service. Still, people complained when they had to shell out $130 for a replacement from Mazda...............

Mark Childers

I don't understand what makes some batteries last for years and years and some not. My Peugeot diesel needs a new battery every three years without fail. Actually just over three years, so you can't claim on the warranty. The twin 6 volters in my MGB were new in 1994 and are still going strong. Both cars get similar amounts of use. Both batteries are completely neglected - never cleaned, never topped up, 'cos I'm a lazy so-and-so.

Mike
Mike Howlett

Cecil makes an interesting point about the battery clamp.

My 12v battery is held down by a webbing strap - similar to what you get on the shoulder straps of a backpack. Im wondering if this is suggicient to pass the UK MOT test, or does the clamp need to be metal?

The car passed its last MOT like this, but Im betting that most MOT testers dont know where the battery is to check it anyway.
Richard

Mine didn't have any battery restraint when I bought it and passed an MOT. The battery isn't mentioned on either of two reference sites I use.
Paul Hunt

I have a 91 Miata with the original battery in it!! It uses 'gel mat' technology which is far superior to the 'wet' lead acid design of most batteries. I can't believe the battery is still good but it is.
Mike MaGee

Pual your right about the battery security, however I was under the impression it was part of the MOT at one time too.
Any battery should be secured for one's own safety in the lease case.
Here is a good MOT site for thoese who want to know more.

http://www.motuk.co.uk/mot_testing.htm

Just to show you the UK is not the only ones with silly motoring rules. Here in the Netherlands I am trying to register my B. I took it along to the RDW to obtain a Dutch registration. They inspeceted the car but it failed on one thing. I do not have a chassis number engraved on the body, the existing pop-rivited plate was not acceptable! Now I have to wait until Feb for the number to be engraved becasue only the RDW inpsector must do this. However a firend of mine who does APK (Dutch MOTs) says that it is not part of the inspection!
I wonder why I have to wait months for soemthing that know one will need to see?
Cecil Kimber

That's one I use, the other is http://www.bobmckay.co.uk/Frame2.html

I suppose your problem with the VIN is because this is its first registration in Holland. It seems that the UK MOT accepts either stamped numbers or plates, which surprises me, and they don't seem to be required at all for vehicles manufactured before 1st August 1980 which also surprises me.
Paul Hunt

Would a MOT tester know where the battery is?

Paul
Paul Wiley

Paul
In answer to your question is yes. Either because he/she is old enough/ keen enough to know about our cars or when he /she (?) gets underneath to look for rust and inspect the brake and petrol lines etc then they will see where the battery is located. But as it has been already established it does not matter.
Cecil Kimber

Colin
On my ´79 RB, I use a 62A Varta Silver Technology battery. It is infact the same type of battery that I use on my SAAB 9000 2.0t. The beauty of it, is that I can circulate it between the turbo and the MG. Therefore I can keep the MG battery in good shape for longer time. A battery needs to workout on regular bases to keep fit. Recognize this from elsewhere??:>

The Varta website in UK has all relevant battery information on their homepage. The battery recomendation table is a PDF-file.

By saying that
I wish you all a Merry Christmas and a Happy New Year.

Erik
Erik

So this Panasonic battery must be similar to the Optima and Exide batteries we get over here I suppose?

Jim
Jim Blackwood

Cecil,
When I was living in Hawaii I failed the safety inspection because my washer jets weren't working. Checking out the rules with the DMV (our version of the MOT) confirmed that this wasn't even a part of the inspection! I guess this happens all over. But at least now my jets work.
Adam Birnbaum

I bought a Moss battery box for a 66 thinking I'd save myself some trouble.
Took the box to NAPA, Walmart, Sears, Auto Zone, Advance Auto, and Pep Boys trying to find a battery that would fit - as Donnie Brasco would say, "Forget about it". Had to cut one end off and add to the box to make enough room.

Moss has since changed the wording in their description.

Glad I did it the easy way - glove box revisited.
Glenn Kendall

This thread was discussed between 17/12/2003 and 25/12/2003

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