XSeries-forum

I need to replace my battery. I ave always used a Bosch Silver s5 but can remember the second half of the spec - I think is is 100 mah 019 (or similar) can anyone advice please - X5 is usually the man for these things. Currently there is too much stuff in the boot to access the old one and I want to get it ordered before I need to clear it all out to replace it.

Also, before replacing the battery is there a quick/easy way to test the alternator.

Ive checked battery output via the hidden menu - at idle is is 11.9/12v. Running at 70 on the motorway is it around 13.7v and with everything on full lights heater etc) it drops to around 13.0 and stays there.

Just the battery or alternator as well?

Those voltages are far to low, at idle I get 13.7minimum, running with anything more than idle it floats between 13.8/14v doesn’t matter how much I switch on.

What are you getting with it turned off as I assume you have a battery problem and its seems to be working ok ish at 70 mph ?

90Ah 019 format. If you have an AGM battery then match it, though as the E53 doesn’t have intelligent charging there’s no recoding to do. Standard and AGM batteries were fitted. A 95Ah or 100Ah will be fine too. The 019 is the size/terminal layout.

I have put a Yuasa battery on the X6. Slightly cheaper and a longer warranty than Bosch. Got it from Tayna who were cheaper than even a discounted ECP price and delivered overnight.

You should be seeing around 12.6V fully charged and 13.8V engine running and normal electrical ‘load’, so if it’s struggling to maintain 13.0V under full load then either the battery is dying or the regulator is failing. Battery is the easiest to change. Be worth charging the battery on delivery too.

Thanks Gents.

X% - what do you mean by the regulator? And could it be anything to do with alternator?

Is there a YUASA spec to look for? How long is their warranty that you mention?

Smee

The voltage regulator is item 5 on your alternator and yes it regulates the alternator output. The one for my water cooled alternator was £28. The YUASA battery I have fitted is 100Ah and the usual 019 which fits our vehicles. Been in a couple of years, no problems yet.
Remember I’m showing a pic of your regulator I’m not saying that is your problem,

Yuasa YBX5019
https://www.tayna.co.uk/car-batteries/yuasa/ybx5019/
Got 2 one on my e53 3.0 diesel and the second on my e90 320d (bit of a tight fit on the e90 but does fit)
edit.
Same price on amazon but free delivery.
https://www.amazon.co.uk/Yuasa-YBX5019- ... B00KNQS4RW

Remember if you do fit a new battery all your problems will seem to be solved, but things will quickly go downhill if you have an alternator issue.

henrym3 wrote: ↑Sun Jun 23, 2019 7:46 pm Remember if you do fit a new battery all your problems will seem to be solved, but things will quickly go downhill if you have an alternator issue.

Thank - so is there a way to check for that. I do believe it is the battery. For example the 4wd light has been on the last couple of weeks and I left the boot slightly open at the weekend. Jump started the car with the battery pack I carry around and the 4wd light went off. Then drove for 4 hours on the motorway no stops and all started fine this morning (so i think it the alternator was recharging the battery I would have noticed after the long drive and overnight stand

Is there way to test the alternator and is there a way to test the regulator?

I suppose you could just look in the hidden menu what your charge voltage is while driving but on reading your first post I see you only get 13v when driving at 70mph which would indicate you have an alternator problem. It could be a bad earth connection ie engine to chassis/battery earth. But, I think you need to check the output at the alternator, you can switch on lights, heated seats, rear window and rev to 1000/1500 rpm and if not getting at least 13.8v you have an alternator problem. Of course an auto electrician should be able to diagnose for very little money.
I drove mine this morning and because of this thread I monitored the voltage and never got down anywhere near 13v

henrym3 wrote: ↑Mon Jun 24, 2019 8:23 pm I suppose you could just look in the hidden menu what your charge voltage is while driving but on reading your first post I see you only get 13v when driving at 70mph which would indicate you have an alternator problem. It could be a bad earth connection ie engine to chassis/battery earth. But, I think you need to check the output at the alternator, you can switch on lights, heated seats, rear window and rev to 1000/1500 rpm and if not getting at least 13.8v you have an alternator problem. Of course an auto electrician should be able to diagnose for very little money.
I drove mine this morning and because of this thread I monitored the voltage and never got down anywhere near 13v

When you say you never got down near 13v, what did you get down to, what electicals were on and how far didi you go?
If I had an alternator problem would i not struggle the next day after a long run if the alternator hadnt been charging the battery properly ?
THe 13v I reported was with quite literally everything I could think of switched on (Fan on max power, lights, fog lights, radio, sat nav, heated seats front and back, front wipers, rear wipers, cruise control, rear window demister, interior lights etc, . Generally it would be around 13.7/13.8 at 70mph with just, say, aircon and radio
Yesterday I started the car and noticed it dropped to 8.6v while cranking although came back up quite quickly to 13.7

Sounds like the battery is charging but not much life if any left in it.
Time for a new one me thinks.

I found that even when my previous battery was coming to the end of life the alternator still pumped in 13.8/14v the battery just couldn’t hold it for long. Nowadays I mainly do short runs but just been to Ireland and irrespective of distance or load I am always between 13.8/14v. I can say this with some confidence because of the item fitted in picture

henrym3 wrote: ↑Wed Jun 26, 2019 3:25 pm I found that even when my previous battery was coming to the end of life the alternator still pumped in 13.8/14v the battery just couldn’t hold it for long. Nowadays I mainly do short runs but just been to Ireland and irrespective of distance or load I am always between 13.8/14v. I can say this with some confidence because of the item fitted in picture
368EB976-618A-4FA8-A33E-222130168F26.jpeg

Thanks to everyone for their replies. Yes I suspect it is the battery. What is the gizmo you have fitted, do tell?

Smee

I have a similar thing in my e53 up by the map lights but it also has 2 usb ports 1 i use for my dash cam.(i didn't fit the cover)
https://www.amazon.co.uk/CHGeek-Charger ... ay&sr=8-11