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Old Oct 11th, 2021, 19:56   #13
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Last Online: May 23rd, 2022 17:19
Join Date: Dec 2013
Location: Wiltshire

Originally Posted by Laird Scooby View Post
If you try a new battery, ensure it is NOT a calcium/silver-calcium variety. Your alternator is NOT capable of charging this type, try a Halfords HB096, it's a traditional lead-acid battery that uses lead-antimony as a coating on the plates to help prevent sulphation. Newer batteries use silver-calcium which increases the necessary charging voltage to 14.7V MINIMUM just to start the charging process!

In fact, if your current battery is a calcium variety, this may be your problem.......

Have a read of that, you'll see what i mean. Also do some more research as you will find that 14.4-14.8V is a conservative estimate, it's normally 15.1-14.7V for a calcium battery but the point it does make in that Wiki page is that calcium batteries do deteriorate rapidly if they're not being fully charged at the correct voltage.
Well, I didn't know that so thanks for enlightening me.

I will check current (electricity pun) battery to see if it is silvery.

Originally Posted by TonyS9 View Post
Sounds more like you either have a short or a bad connection, if the battery is good.

You cannot discharge the battery in 1min, something would go on fire, there would be smoke.

You need a better test for the battery than measuring the voltage, you need a load test like a high wattage bulb ideally..try not to blind yourself. Sparking the battery terminals can also work with a short piece of wire, but needs to be done carefully as if you allow it to contact for any length of time it will weld, overheat, go on fire, explode the battery etc,,.. thats a bad day.

A problem that has been reported before is the starter cable chaffing on the bulkheak, but I think that is more of a 740 problem than 940.

Try measuring the battery voltage at, say the cigarette lighter socket after measuring at the battery (with the ignition on).
Please could you tell me where all the earth leads are? As I see it, there is an earthing point just behind the battery on the chassis rail (left hand side, front of engine bay as you stand in front of car). There are a pair of plaited or braided earth cables from bulkhead to block (middle of engine bay and closest to the scuttle/windscreen). I assume there is something meaty hanging from the gearbox or something?


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