Reg Posted May 12 Share Posted May 12 I have a year 2000 1800 K-series Roadsport which has spent the winter resting attached to an Optimate 2 battery conditioner. It has a nearly 5 year old standard Banner 530034 with correct fluid levels and has never been flattened. As usual, after an extended period of no use, I disconnected the HT feed to the distributor and cranked to get oil pressure. The engine cranked vigorously for several turns. I did some work on the car during the course of which I started it several times. Then I drove it 300 metres to my MoT tester. When I came to pick it up (it passed!) I got what I initially thought was the 'click of death' except the engine wasn't hot. A jump pack got it started and I took it home. I plugged it into an Optimate 6 ('cos I figured that might do a better job of checking the battery than the much older Optimate 2). Within a couple of hours the Optimate indicated that the battery is fine and dandy and it is indeed showing well over 12.5v. So I tried turning the LED headlights on - initially nothing, then a flicker and then full power. I then pulled the HT lead and, with a voltmeter on the battery, I tried to spin the engine - the voltage plummeted to below 2v for as long as I held the red button down and didn't spin, just clicked. When I released the red button the voltage rapidly climbed back up to over 12v. Then I turned the headlights on and measured the voltage - it dropped to 9.8v. Is this simply a failed battery or is something more sinister afoot? It just seems strange that neither battery conditioner has identified that the battery's knackered and that it went from fully functional to utterly useless in the space of a couple of starts. Opinions gratefully received. Cheers Reg Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted May 12 Member Share Posted May 12 First, a bit on practical testing, The most useful test of battery condition is holding its voltage against a high load. Specialist kit is available but for most of us the best way is using the starter motor/engine as the load and measuring the minimum voltage during cranking. It's convenient to also measure the voltage at rest and at 3,000 rpm. The latter gives a lot of information about the on-board charging system. Those three values van be used to spot early deterioration (check them routinely with the fluid levels), to find the cause of individual problems and as a transferable metric so that we can discuss what's going on in other people's Sevens. ... Poor battery condition can be the cause of poor starting even when the cranking speed sounds normal. This has been repeatedly observed and has caused surprise. It's probably because electronic components such as the ECU are dropping out when the voltage drops. ... LED headlamps are a much lower load than the starter + engine. Incandescent headlamps are higher load than LED but still low. Of course their brightness also acts a measure of current and thus of battery voltage, but not as good as that measured voltage. ... Many of us use the display from smart conditions chargers in order to follow what's happening. I once wasted a lot of time because I trusted a CTEK when it wasn't doing its job at all. Bit the little lights fooled me into thinking that it was following its cycle as normal. There might be another example of this happening to another Member at the moment. ... So, battery value at rest, minimum during cranking, and at 3.000 rpm, please. Jonathan Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted May 12 Member Share Posted May 12 Second: what does the click mean? Only that something is activating but the engine isn't turning over. There's a long list of causes and I'd recommend a systematic exploration when it happens. Starting with those three measurements of voltage. Jonathan Link to comment Share on other sites More sharing options...
JP Posted May 12 Share Posted May 12 If you look a little further down at my thread about my 1.6K cutting out at idle, you'll find the voltage values that you're looking for. I've starting getting the K-click following my rebuild which I have never had trouble with before. The last time, I pulled the FIA key (and I think I heard a click), then switched it back on again and it fired up. And the car was still very toasty? There are bucket loads of threads on the K-click (which I now need to go through...) 1 Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted May 12 Member Share Posted May 12 And... what's happening here? I suspect that the battery is knackered. I'd now do something like the following: 1 Check the fluid levels again. 2 Jump start from another battery or vehicle into your existing battery connections (and therefore existing other wiring and components and connections).and see what happens, including those measurements of voltage. 3 Be suspicious about those smart conditioning chargers. If you can get the engine started you have another independent way of charging the battery... and you'll have already checked the on-board system with the measurement of voltage at 3.000 rpm. Jonathan Link to comment Share on other sites More sharing options...
Reg Posted May 12 Author Share Posted May 12 Thanks for the quick response Jonathan At rest, engine off, no load - 12.70v Cranking (except it doesn't actually crank) lowest recorded value - 1.88v At 3,000rpm - 14.00v It took a bit of effort to get the last reading as a fully charged Noco Boost jump pack had no effect whatsoever. I have a spare battery kicking around so I successfully jumped it off that. Which begs the rhetorical question what's the point of the Noco Boost if it won't jump a car with a battery showing 12.7v. Cheers Reg Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted May 12 Member Share Posted May 12 Thanks I'd now check the fluid levels again. And then charge it from the alternator or a dumb charger. And then retest. Jonathan Link to comment Share on other sites More sharing options...
Reg Posted May 12 Author Share Posted May 12 Thanks JP and Jonathan. Fluid levels are fine. I could indeed charge it and it may then work normally but I'll never trust it again, particularly in that it appears the Noco jump pack won't get me out of trouble if it recurs. It's sounding to me like it's time for a new battery unless anyone can suggest some other fault that is causing this behaviour? Cheers Reg Link to comment Share on other sites More sharing options...
Reg Posted May 12 Author Share Posted May 12 Incidentally, I did get the Noco Boost to work by pressing its 'override' button which the manual says is for batteries with a voltage below 2v. Why that was necessary when the battery was showing over 12v is anyone's guess. Link to comment Share on other sites More sharing options...
Gridgway Posted May 12 Share Posted May 12 Time to stop testing and buy a new battery. It's dead! Link to comment Share on other sites More sharing options...
Reg Posted May 12 Author Share Posted May 12 Yes indeed, it's probably pining for the fjords. Link to comment Share on other sites More sharing options...
jbcollier Posted May 12 Share Posted May 12 Go through your battery connections — both at the battery and where they connect to the solenoid and frame/engine. All good? Battery is toast. Link to comment Share on other sites More sharing options...
Gridgway Posted May 12 Share Posted May 12 Seriously, the battery is toast! Link to comment Share on other sites More sharing options...
Reg Posted May 12 Author Share Posted May 12 2 hours ago, jbcollier said: Go through your battery connections — both at the battery and where they connect to the solenoid and frame/engine. All good? Battery is toast. Yup, all good, clean, uncorroded and secure. The verdict is unanimous - the battery is toast. Link to comment Share on other sites More sharing options...
ScottR400D Posted May 13 Share Posted May 13 “have a year 2000 1800 K-series Roadsport which has spent the winter resting attached to an Optimate 2 battery conditioner” Better to isolate/disconnect than leave on any charger all winter. Link to comment Share on other sites More sharing options...
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