MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG Midget and Sprite Technical - Jump starting a postive earth car

The battery on my Midget has died,and I need to jump start it so I can drive it to a garage to replace the battery. I have a jump starter; the instructions seem to be written assuming it will be used with a negative-earthed car, but my Midget is positive-earthed. The jump starter instructions state to connect the positive clamp of the jump starter to the positive terminal of the battery, but then states the negative clamp of the jump starter must NOT be connected to the negative terminal of the battery due to a risk of explosion. Instead, it should be attached to some bare metal of the chassis. For my car, should I reverse these instructions, connecting the negative clamp to the negative terminal of the battery, then connect the positive clamp to some bare metal of the chassis??
Adrian Jones

You are correct. The reason you don't connect both jumper terminals to the battery is because even a dead battery can have explosive gases venting from it. A spark can set them off. For positive earth vehicles the negative jumper lead goes to the battery negative post / terminal & the positive jumper lead goes to a good ground on the engine somewhere away from the battery. If you are jumping it from another vehicle (particularly if the jumper vehicle is negative ground) make sure their is no contact between the 2 vehicles other than the jumper cables.
s1

Years ago when I asked this question, somebody gave me the safe order of attachment and detachment of the four clamps, which I found very reassuring. I think it was Will Munns - not heard of for many years.

Can't find it now, unfortunately.
Nick and Cherry Scoop

Jump-started the car successfully this morning.
I chose a bad location for the positive clamp first of all, which was a poor earth and the engine wouldn't turn over. Chose to connect the clamp to the positive terminal of the battery (!) and the car started first time.
Now my car has a new battery has anyone got any recommendations for one of those small
maintenance/trickle chargers that can be connected to the
car for long periods whilst the car is not being used??

Adrian Jones

Adrian

I use an Optimiate 5 battery charger/recycler (the ''5' model suits the capacity of car batteries, unlike the lower numbered models for motorbike batteries).

You can buy these as Opimate branded direct from Optiimate, or via Honda motorcycle dealers as Honda Optimate 5.

www.accumate.co.uk/optimate%205.htm

http://www.ebay.co.uk/itm/New-Genuine-Honda-Optimate-5-Battery-Charger-Optimiser-Conditioner-Car-Bike-/170929598023?hash=item27cc32ae47:m:mcv-MfM-97mgwdCMfejeVrw

Cheers
Mike

PS It works well, but with confusing lights and over complex explanatory Info leaflet.
M Wood

How many different ways can you spell optimate ? 😀
Dave O'Neill 2

Reminds me of the Lewis and Clark expedition in 1804-1805 to explore the Louisiana Purchase. The one who wrote their journal (don't remember which one) spelled Sioux 27 different ways but not once did he write SIOUX. Go figure. ;-)
Martin

Apologies for my sub-optimal spelling. One of the three is correct!

My lame excuses are sausage finger typing on an iPad when tired and possible mild dys... (not gonna attempt that one). Plus silly name for a bit of kit.

Anyway, any more charger recommendations for the OP?

Whatever the Optiwotsitdoodah 5 is called it works, albeit with too many odd flashing indicator lights to over-inform you of progress through every automatic operating step, combined with a rather overblown info sheet describing how it works - just read how to connect it and wait for two non-flashing green lights to appear to indicate a fully charged battery.

Prop - got any recommendations?

Cheers
Mike

PS Martin - did anyone try to sue over the Lewis and Clark case you mention?
M Wood

Mike,

Were you trying to write lysdexia (learned that word from someone who was dyslexic).

And no one sued since Lewis and Clark were long gone by the time the Sioux got lawyers.
Martin

Mike

My iPad didn't want me to write optimate at all. It made it into two different words, neither of which made any sense.

Don't you just love technology?!
Dave O'Neill 2

I use a Ring smart charger that seems to work well enough. On my frogeye, I fitted a cigarette lighter socket to the permanent live feed, and put the appropriate plug on the charger, so I can just plug it straight in there, which makes life nice and easy.
But I am still positive earth, so it was important to source a plastic cigarette lighter socket for obvious reasons.

Ps. Your banter reminds me of the story of the dislexic, agnostic, insomniac who stayed awake all night wondering if there really was a dog.

Graham
Graham V

Adrian,
my neighbour got a combined charger/conditioner that looked like a CTEK but wasn't from Aldi for about £15 has worked well for a couple of years so that type is available but probably not at £15, I think it was reduced from about £30+.

I've used a basic Optimate for at least 15 years, mainly to recover my neighbours' batteries, it may take up to a couple of days if the battery seemed beyond saving but it's always got there. It didn't like being in the shed at -10c so I did once have to bring it inside (8c) for a while to warm up the electronics but again it worked fine after his.

My Midget is standard and battery new(-ish) and it sits outside 365 days a year but I'd still expect the car to start even in the coldest part of winter even if it hadn't been started for a month or more so I do wonder what caused your battery to go so flat and if you really need a battery conditioner.
Nigel Atkins

Thanks for your suggestions - the Optimate 5 looks very interesting. It's possible it may have been able to 'rescue' my old battery.
Nigel - the battery was ten years old, and the car was last driven back in mid-November.
Adrian Jones

Hi Adrian,
oh, I see.

I think a 10 year old battery usually can be saved, by coincidence the last one I done for my neigbour was 11 years old and I've done older. Slow and steady is the way, I've got a cheap 20 year old charger with needle dial so I can usually tell within 5 minutes if the battery is picking up and if it's going to be a long job. Modern chargers with the lights are yes or no, red or green (though some have amber lights too) so they don't give as much info plus I think some require the battery to have 6v or the charger (like a lot of computers) says "no".

I use my old battery charger to get the battery nearly full then swap to my Accumate (I've just remembered that's what mine's called, sorry I've got very serve man-flu) to get the battery fully topped up but again my Accumate only has amber and green lights for charging so it could literally change from amber to green as I turn my back and walk away.

As John Twist says the battery is possibly the most oversold part on a car - but I change them as soon as they become unreliable as I can't stand a car that won't start, if the car starts at least you limp to where you're going, or to trace a fault on the car or make repairs or adjustment.

Nigel Atkins

This thread was discussed between 12/04/2017 and 14/04/2017

MG Midget and Sprite Technical index

This thread is from the archives. Join the live MG Midget and Sprite Technical BBS now