BarryM

I was trying to demonstrate that the battery voltage had barely moved over 48hrs which indicated no parasitic drain, I'm doing a 400mile round trip this weekend so that should give it a charge

Thanks for your input Clavurion,, too late I’m afraid as I went with another Bosch S5 020:on the basis the last one had done ok (no more than ok though in my opinion). I installed the battery on Tuesday evening and noted the voltage @ 12.36v and purposely didn’t charge the battery or lock the car. 48hrs later and the battery reads 12.35v so I think that points to a seriously failed battery instead of a parasitic draw.

I guess my concern was the knackered AGM battery on the bike I bought had been charged on a regular battery charger and potentially killed it, and then I figured it could be overcharged by the alternator constantly charging it without electronics to monitor charging rate but I might be over thinking it all!

CTEK was showing a full set of LEDs this morning suggesting battery was all good.....13.34v after disconnecting the charger and then down to 12.85v an hour later. I'm off out until this afternoon but gonna see what happens to it after I try starting the car! I will definitely be ordering a new battery before I use the car in anger again, have read some interesting stuff about how you have to be careful not to overcharge an AGM battery and as the E39 has no electronics to regulate the charge going back into the battery I'm not so sure getting one is a good move. I recently bought a used motorbike that had a duff AGM battery and the chap had been using a regular battery charger instead of a dedicated AGM type charger which I think killed it so I need to look into AGM a bit more yet.

Thanks for the replies. I connected my battery pack which managed to put a bit of power into the Bosch and then connected the CTEK which was tricked into thinking the battery had enough charge so started charging it - currently on led 3 of 7 so I'll have a look tomorrow. I immediately used my remote to turn off the alarm in case the charging failed and set it off. My FSU failed years ago so I know about that and being the paranoid type I often check the charging rate whilst driving so I know the alternator is doing its job. I'm keeping my fingers crossed the battery just had a massive failure as off for a few days towards the end of next week with a 4hr drive each way, my little battery pack always starts the car if I've been tinkering about on the drive for too long with the doors open etc so I know I have a way to start the car if it has developed a parasitic drain. I've been thinking for a while the battery was past it's best and the CTEK has just masked it by always keeping it in good condition so I'll give some thought to what to replace it with. I had a Varta before this Bosch so that's 2 batteries in 10yrs which isn't too bad I guess.

tbh I'm not sure anything would take it down to 1v - surely if it was a drain the battery would be at 0, although I've never really thought of checking a battery voltage when it was flat before. I guess I did it because the car was fine only last week so was a bit confused.

Not used the car much recently but went out to the garage today and remote wouldn't work so after unlocking it manually I stuck a multimeter on the battery and it reads 1.06v.....I did drive it a week ago but reckon it must have suffered some kind of major failure! It's a Bosch S5 0120 from 2016 and spent lots of time on a CTEK battery tender but today the CTEK just has a flashing green light which apparently happens at <2v Thinking I might go for one of the AGM batteries as the car has spent quite a lot of time sitting in the garage recently!

You might as well have taken it to a BMW dealer!

Car is garaged but done 128k on that suspension, they look in pretty good condition given the age - and I sent you a PM earlier.

I think you should park the V8s idea, what you want is the right stuff for your car. I contacted Alpina direct and got the PNs and then ordered the full kit from Alloy Wheels Direct who are very good (I would never order an Alpina part through the BMW network as they're clueless and charge you more). I've just checked back and I've managed to do around £3k miles in the last year which seems quite good given covid restrictions.....as I said in my post following installation the difference is pretty minimal which is surprising but when you look at my old stuff it still looks in very good condition which is impressive after 20 odd years. My front springs are PN 31 33 632 so if you can confirm what yours are then I can probably help you out, will drop you a PM.

What you need is a B10 owner who did a full suspension refresh and still has the old stuff sitting in his garage doing nothing

Great work as always but I’d leave that for show and stick one of these in your door pocket if you want something that would actually help in an emergency: https://firesafetystick.com/

I run it up to 6k but not beyond when I go out for a blast, the UK roads are too busy most of the time :(

Mine is wildly optimistic!

You guys need to get out more I had my alternator repaired maybe 6/7 years ago and touch wood it’s been fine since but you never know when your E39 is gonna surprise you!