www.jec.org.uk

A friend of mine has a XKR-S and fitted a new Bosch battery in 2024. The battery is dead and is reading 2.94V. He has got in touch with the seller and his response is as follows;
I am just emailing regarding the outcome of your warranty claim. The warranty on your battery covers all faults caused by manufacturing workmanship or material. The warranty however does not cover the following Non-Manufacturing Defects like sulphation, Wear and Tear, Deep or Over Cycling, Overcharging, or undercharging, Case damage, Terminal damage, Incorrect Application, Fault Diagnosis / Installation. As the voltage is below 10.4V, a process of sulphation occurs. Sulphation is a build-up of lead sulphate crystals and this can cause loss of cranking power, longer charging times and premature battery life. Crystals can build naturally in a battery, but with regular use and charging of the battery the crystals are small enough to be broken down. However, at the point of sulphation these crystals are so big that they cannot be broken down by the battery’s natural process. This reduces the conductive area on the metal plates inside of the battery, which means there is less usable capacity.
As your battery’s voltage is reading 2.94V, the battery is fully discharged, however as the battery has not been recharged sufficiently it has led the voltage to drop further to the point of sulphation. This then prevents the battery from working to its full capacity again. Unfortunately, based on these details which are stated in our terms, we are unable to replace this battery under the warranty and it is now void.

I would welcome any comments with regards to this explanation. As you can imagine my friend is not best pleased as it was also sold with a four year warranty.

That's very annoying for your friend but how did he let the battery voltage get so low? If he did not use the car very often surely he should have used a maintenance charger to keep it in good condition?
I must say my experience with Bosch Silver Star batteries has been quite uneventful. The one in my X308 lasted about 9 years; I put another one in a diesel X350 (but only kept that a couple of years) since when I've had a V8 X350 where I replaced the original Jaguar battery with a Bosch one. This has lasted over eight years until replaced this February: the only reason for replacement was the slightly lower voltage on cranking throwing up spurious fault codes, for which X350s are well known when the battery is not 100%. I fully expect this battery to go another 8 years. All batteries purchased online from Tayna Batteries with excellent next-day delivery and quality packaging.

It has been on a Ctek charger when not in use. The question I had was how does they know the issue with the battery without inspecting it. They want to charge my friend to inspect it and if it’s found faulty, they will replace it. There is no suggestion the inspection charge will be refunded!