Battery SoH vs SoC

[TeamG]

I’ve a few general questions, prompted by investigating my current car battery and considering when to replace.

My XC60 is approaching 7 years old, 55k miles. It’s on the original battery (EFB start-stop 70Ah and 720CCA). I’ve regularly conditioned and charged using a Ctek device, every couple of months in the summer and couple of weeks in the winter. Working from home a couple of days a week and driveway with handy outdoor socket makes this easy for me.

By doing this, I’ve always had start-stop available (then always turning it off when I start the engine) and no starting or other issues. Before a charge, I’m usually mid-70s State of Charge (SoC), although being confined to the local area post-Covid for 7 weeks has meant that this has dropped to 63/64% if not used for a week or two. A charge gets this back up to 86% or so and all good.

Yesterday, I used a Topdon battery tester to test all our cars State of Health (SoH), which is a measure of battery condition/capacity as a proportion of a new battery condition. For the Volvo, it was showing 34% SoH, with a maximum available 444 CCA rather than the new 720 CCA. The tester suggested red “replace immediately” based on SoC, but was showing green for cranking test and charging test and I’m experiencing no issues.

I now have a dilemma. Do I replace immediately, virtually eliminating any starting or reliability issues (£148.32 discounted genuine Volvo or £115.78 Exide delivered from Tanya), or keep going? I’ve no starting issues at -3/-4 degrees, so the reduced CCA doesn’t seem an issue and the weather is only going to be cold for another month or so. If I get happily to spring, then I can ride out the summer and replace late autumn saving the immediate burden on cash flow! I’m not overly worried about breakdowns - a jumpstarter in the boot will deal with any when I’m out and about.

On the other hand, this battery has lasted ~7 years and if I keep the car 3-5yrs, then am I best replacing now and getting the longest personal benefit from it?

What would others do in this situation?

[4x4]

Something to keep in mind is your original Volvo battery will last many more years than any replacement including a Volvo replacement. I sold my XC90 last April with its original 13 year old battery and the new owner is still using the car daily. If it is working then there is no need to change it yet, wait until it shows signs of failing since you have a jump starter in the boot

[Pidgeonpost]

Personally I'd carry on with monitoring and the occasional top-up. This should give you a heads-up in case the battery shows signs of imminent death, in which case a new one isn't usually more than 24-48 hours away. If it holds up across the summer then consider replacing before the winter. As @4x4 says, original batteries tend to be more long-lived than replacements.

[ITSv40]

'er indoors Mini Cooper has the original factory fitted battery. Stop start used all the time, car used 2-3 times a week for some short journeys and longer ones. Battery still all good after 17 years and no issues at all. Car has done 102,000miles so the battery has had some use.

If your battery is performing as expected, I would carry on with it.