Battery Selection advice required

[SimonH450P]

Just got a ‘77 XJ 4.2 Coupe and the battery is dead (I was aware up front on this).
Anyway, the manual seems to call for a 55. - 66 Ah battery. This seems a little low these days and there is no mention of any CCA requirement for this big ol lump to be turned over.

What are people using, getting good performance from these days?

[JimMann]

Hi Simon, battery technology has moved on quite substantially, but the good news is that your new car does not have the voltage sensitive electronics of the more modern machinery.

The advice is to ensure you select a battery with the dimensions to fit into the battery tray on the car and be secured perfectly. It is an MoT failure to have an unsecured battery. Then you can look at capacity and obviously you have the guide from the Owners Manual. Fitting a higher capacity battery such as a 90Ah with higher CCA might sound like a great idea, but you would need confirmation that your alternator and circuits can use that additional capacity - it may well just be wasted power / expense.

I like Yuasa batteries, but Tayna are also well thought of elsewhere on this Forum.

Jim Mann

[SimonH450P]

Thank you for the reply Jim.

So size is important, and getting 55 — 66 Ah might be about right for the old car.

I will dig at the tech specs for correct sizing.

I normally favour Varta or Yuasa, I will start there.

[ptjs1]

SimonH450P,

Tayna are an online supplier not a brand. They are extremely good, offering a huge range of different brands, I have very rarely ever found any other retailer to be cheaper than Tayna. They arrive very well packaged, usually the next day. I've been using them for years. Great service. Give them a look.

https://www.tayna.co.uk

Paul

[SimonH450P]

Further to this, it looks like a good size is a 072 format to fit well in the battery box dimensions, though when going online, Tayna etc, they all seem to recommend an 069 format. Which, to me appears to be a tad large.

[mike020150]

My series 2 XJ is currently fitted with a Varta 70Ah unit which the invoice lists as, "069 071 072". In practice, to fit the larger sizes, it may be necessary to file the top of the battery box opening to allow the box to sit fully down. Mike.