Thread: Beware Charging Dual Battery in D4.

Originally Posted by Blknight.aus

actually...

they allow for the primary starting battery (when new) to be down to about a 70-60% SOC and still be able to reliabley start the vehicle.

They didn't put a big enough one in the D4s for the showroom floor, with so many of them with a flat battery from people opening the doors for a squiz.

Originally Posted by Graeme

They didn't put a big enough one in the D4s for the showroom floor, with so many of them with a flat battery from people opening the doors for a squiz.

The D4 is just the latest with this problem and is not as bad as the first version of the L322 Range Rovers.

You will often see battery chargers pushed under the showroom vehicles while customers are around.

Originally Posted by Blknight.aus

actually...

they allow for the primary starting battery (when new) to be down to about a 70-60% SOC and still be able to reliabley start the vehicle.

Hi Dave, I’ve tested quite a few new vehicles and taken their cranking batteries down to 20-25% SoC and had no trouble stating them and they were all cold starts.

Over 20 years ago, when I first started making the isolators, I tested a good few vehicles back then and most could be started using batteries at 30-35% SoC but a few older ( back then ) diesels would not start at much below 50% and that’s why I set the SC80 at 50% for the cut-out.

Not only have the vehicles improved, with the likes of fuel injection but today's standard cranking batteries are a quantum leap ahead of the old ones.

Originally Posted by Blknight.aus

actually...

they allow for the primary starting battery (when new) to be down to about a 70-60% SOC and still be able to reliabley start the vehicle.

Thanks blknight, 50% SOC (state of charge) IS well below the 70-60% required by manufacturers if what you say is correct.

Originally Posted by Wilbur

Thanks blknight, 50% SOC (state of charge) IS well below the 70-60% required by manufacturers if what you say is correct.

So Wilbur, what your saying is that 10% difference between what I use, 50% and the 60% that Dave has quoted is a huge difference but 40% lower than your claim of needing a fully charged battery to start a vehicle is not that much different.

Mate, as previously posted, you wouldn’t know what the truth was if it jumped shook your hand.

yep now you can, back in the day.....

IMHO it falls into the same sort of catagory as the calcium batteries.

This "new" Style of battery that performs worlds ahead of the old batteries is still tested and speced as per the old standards so to create a rough example what was once a battery that would class as a 700CCA battery that needed to have a SOC of 70% to pass the testing standard is now a 700CCA battery that can pass the test with a SOC of 30%. (for now I'll refer to this minimum SOC as the "reserve of charge"

the problem with this is....

where an old school battery which needed a higher SOC to do the job usually dies off gradually as its capacity deminishes the new school battery which has a lower SOC requirement to do the same job keeps on cranking with no apparent loss of ability untill their capacity drops too low and then they dont have the reserve to go close enough to doing the job.

the reason behind why?

simple modern cars have a lot higher residual draw on the battery than an old school car.

Any word on when those new cable-less kits are coming?

Hi Dave and the lowest you could repeatedly cycle, as you put it well, an “old style“ cranking battery was 50% with out harming the operating life span of the battery.

The Ca/Ca batteries haven't been round long enough to see if they can be cycled to a lower SoC and still have a good life span.

I haven’t come across anything indicating the manufacturers are are changing the 50% SoC cycle rates for Ca/Ca cranking batteries, Dave have you seen anything different to this.