1955 XK140 12V battery advice
Discussion
Just purchased a 1955 XK140, Battery is 12V and was on car when purchased this week and has recharge date of 2009 suggesting quite old. It's a Yuasa 1000 YBX1065 12V 54Ah 470A. It's 7x7x 9 inches and the access for installation is tight as is the tray as the car probably had two 6v originally. I believe the cranking ampage is woefully inadequate for a car with this engine 3.4litre. The car would not start this morning so battery removed as the Vitesse seemed to be taking all day to try and jump start it. The car is a keeper as is my Vitesse (10years and counting) and is going to be subject to sensitive restoration and lots of use. Has anyone any practical or first hand experience advice on an appropriate battery for the new member of the family?
As long as the car bodies don't touch the fact that it may be pos earth doesn't matter. Neither car nor battery will "know" the difference. If you let the cars touch during this process then you will have fireworks, and possibly damage to all sorts of things, including you.
If you connect a charger the wrong way you will kill the charger first, then maybe the battery. Maybe not. But earth polarity isn't a problem. Think it through, you are connecting a 12V DC supply the right way to a battery which is in an isolated system where ground happens to be +12V and positive zero.
I suspect that the battery has died because it's elderly and over the winter it wasn't on a trickle charger. They won't last for ever. My money says that if you get a new decent size battery like the one you are removing you will get more than enough cranking amps and more than enough starting capacity.
If you connect a charger the wrong way you will kill the charger first, then maybe the battery. Maybe not. But earth polarity isn't a problem. Think it through, you are connecting a 12V DC supply the right way to a battery which is in an isolated system where ground happens to be +12V and positive zero.
I suspect that the battery has died because it's elderly and over the winter it wasn't on a trickle charger. They won't last for ever. My money says that if you get a new decent size battery like the one you are removing you will get more than enough cranking amps and more than enough starting capacity.
Reply to all, new battery fitted with approx 30% more power. Car is 12 V now and positive earth so fitted correctly and fired up. I think I did fry the charger but never mind as I've had it years. Been reading up a lot since yesterday so think I get it now, but will to use another expression " measure twice, cut once" in future. Lots of jobs becoming apparent the deeper I dig with the car but it is very nice and they are all surmountable. 
My XK 120 had two 6 volt batteries, each one in a little box behind the seats. After a few years, one wouldn't charge at all and I bought an Odyssey battery - 12 volts- which sits neatly in just one box. It's been totally reliable for three years or so now, combined with a new starter since the original's Bendix gave up. Also means there is a box for sandwiches and a folding umbrella and so forth!
I just replaced the two six volt batteries on my XK120 with two 12volt wired in parallel
https://www.htsspares.com/buy/202e-battery these are 340 amp 40 amp/hour, I am not sure how this multiplies in parallel but I presume it
makes 680 amps and 80 amp/hour. They fit neatly in the battery boxes.
Anyway a good result and they have performed well for several years.
https://www.htsspares.com/buy/202e-battery these are 340 amp 40 amp/hour, I am not sure how this multiplies in parallel but I presume it
makes 680 amps and 80 amp/hour. They fit neatly in the battery boxes.
Anyway a good result and they have performed well for several years.
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