Disco 2 Battery moniter

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Andy Warren

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Hi all, has anyone fitted one of the Sealey battery monitoring devices (to any vehicle) ?
I fitted one a few weeks back & it tells me my D2 battery is losing about 22% of it charge overnight e.g went the Goodwood Revival Sunday & got back about 19.00 & as you would expect the app on my phone for it was showing 100% charged, at 09.30 this morning it's showing 78% charge !
Before I left for GW it was showing 44% & 12.5v as I hadn't used it for a week but it always starts 1st time (before you've let go of the key). Battery C31 -1000 is just over 3 yrs old & done 17,000 miles & the alternator (Hella 120A) is nearly 3 yrs old & has done 15,000 miles. It charges at 14.2v on my MM.
Could this be an early warning for the battery (has 4 yr warranty) or is the BMS not brilliant ?
 

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Never used one of these devices but from the image, it looks like the SoC is being measured using the Voltage Method. Just keep in mind that this method performs well in a controlled environment (i.e. stable voltage, current and temp conditions), which is of course not the case when installed in a vehicle. Hence the accuracy of the readings are not going to be the best even though the algorithm would account for certain fluctuations. Also, lead acid / AGM / Gel batteries lose on average 10% of their SoC with each 0.12V of open-circuit voltage drop. So just don't be alarmed with certain readings as the conditions are not ideal and the margins are very tight.
 
Never used one of these devices but from the image, it looks like the SoC is being measured using the Voltage Method. Just keep in mind that this method performs well in a controlled environment (i.e. stable voltage, current and temp conditions), which is of course not the case when installed in a vehicle. Hence the accuracy of the readings are not going to be the best even though the algorithm would account for certain fluctuations. Also, lead acid / AGM / Gel batteries lose on average 10% of their SoC with each 0.12V of open-circuit voltage drop. So just don't be alarmed with certain readings as the conditions are not ideal and the margins are very tight.
I haven't had a chance to swap batteries yet but 24 hrs later & the truck hasn't been opened or used it's now down to this !
I know it will start 1st time even if I leave it a week, so as you say I'm not overly worried yet as it's still reasonably mild but I know the cold weather will soon impact the battery if it's getting near the end of it's life.
 

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I haven't had a chance to swap batteries yet but 24 hrs later & the truck hasn't been opened or used it's now down to this !
I know it will start 1st time even if I leave it a week, so as you say I'm not overly worried yet as it's still reasonably mild but I know the cold weather will soon impact the battery if it's getting near the end of it's life.
Have you checked the idle current after 30 - 90 minutes after any door activity? It should be around 20mA or less.
 
It may start but you may see other issues if it get's too low. My TD5 would start no problem but refused to rev beyond tickover due to low volts to the ecu.
Hi, I think it was reading about 44% on Sunday when I set off for Goodwood & went fine for the 200 mile round trip but I'll have a better look at the weekend. I use a USB charging thing in the fag lighter which has a built-in volt meter, which was showing the same as my MM 14.2 volts eng. running. Due to the inclement weather I had lights & a/c running + my fridge plugged in (only when the engine was running) 🙂.
 
Hi all, has anyone fitted one of the Sealey battery monitoring devices (to any vehicle) ?
I fitted one a few weeks back & it tells me my D2 battery is losing about 22% of it charge overnight e.g went the Goodwood Revival Sunday & got back about 19.00 & as you would expect the app on my phone for it was showing 100% charged, at 09.30 this morning it's showing 78% charge !
Before I left for GW it was showing 44% & 12.5v as I hadn't used it for a week but it always starts 1st time (before you've let go of the key). Battery C31 -1000 is just over 3 yrs old & done 17,000 miles & the alternator (Hella 120A) is nearly 3 yrs old & has done 15,000 miles. It charges at 14.2v on my MM.
Could this be an early warning for the battery (has 4 yr warranty) or is the BMS not brilliant ?

Hi mate

Don’t know if this helps u but I used one called a BM2 and had the same thing happen

I then went through the settings and could change the SOC setting as it showed a lower % , altered it to a lead acid battery and found it the % read accurately as the battery slowly drained as it should and not a drop like it did before

Have a battery monitor gauge fitted and checked that side by side and indeed the battery itself was ok and the app getting reading a wrong soc % but cured it after I went into the settings of the app

As I have 2 x batteries got the dual battery app as well that can monitor up to 4 x batteries

Recently got another battery monitor from the states that claims to have a better Bluetooth range of some 50’ instead of the 20’ , just to to fit it to test it out

Hope that sort of makes sense mate

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Morning Gary, I will check the settings on it to see what battery type it's set to. I'm guessing something is wrong because I went out in it yesterday & before I started it the BMS was reading 41% & I was expecting the worst as the overnight temperature had dropped to 3 degrees but it just started as always & without the slightest hint of being sluggish to turn over (which I would expect with a battery in that SOC). The find my car bit makes me laugh as well, I took the dog to his usual walking spot, in the D2 6 miles from home & whilst walking him I thought I'd check it's location & it informed me the D2 was still at home 🤣🤣. My phone is set to precise location & in the BMS settings for location are on all the time !
I'll do a parasitic drain test today & see what that reveals but I suspect there's not a lot wrong, thanks & all the best.🙂
On the walk the dog managed to sniff out this mole from about 10 metres away ! It must help the golfers out as those things make a mess of the course.
 

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Morning Gary, I will check the settings on it to see what battery type it's set to. I'm guessing something is wrong because I went out in it yesterday & before I started it the BMS was reading 41% & I was expecting the worst as the overnight temperature had dropped to 3 degrees but it just started as always & without the slightest hint of being sluggish to turn over (which I would expect with a battery in that SOC). The find my car bit makes me laugh as well, I took the dog to his usual walking spot, in the D2 6 miles from home & whilst walking him I thought I'd check it's location & it informed me the D2 was still at home 🤣🤣. My phone is set to precise location & in the BMS settings for location are on all the time !
I'll do a parasitic drain test today & see what that reveals but I suspect there's not a lot wrong, thanks & all the best.🙂
On the walk the dog managed to sniff out this mole from about 10 metres away ! It must help the golfers out as those things make a mess of the course.

Morning mate

Many thks and did u also check the SOC % plse as mine wasn’t at the correct rating

If I remember I set mine to 100% at 12.6 Vdc , it then drained properly over the days and weeks and all showed it correctly

Know uncan also do a crank test via the app so at least then will check ur battery state when it’s being cranked

I can leave mine for a month until it needs charging again

Talking of moles reminds me of jasper carrot when he sat on the swivel chair with a shotgun 🤣

Hope u get it sorted out mate and I wonder if another free app might work

Also done that ref parasitic test and alas couldn’t pull any fuse as it would wake the system back up, not sure how it compares on ur d2 mate

Fingers crossed for u
 
Charged battery all day (disconnected) pic 2, then tonight checked the parasitic drain which was .26mA, pic 1. Is this about right ?
Then a couple of pics of it charging once reconnected. All seems OK so I'll see what the SOC is in the morning.
 

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Charged battery all day (disconnected) pic 2, then tonight checked the parasitic drain which was .26mA, pic 1. Is this about right ?
Then a couple of pics of it charging once reconnected. All seems OK so I'll see what the SOC is in the morning.
This doesn't look right, 0.26mA is unrealistically low. Looking at the first picture, it seems like you have the meter connected incorrectly. The meter is set to mA but the red lead is in the A, not the VΩmA socket. Take care, most meters have a protection fuse, so if your drain is above 200mA etc, the internal fuse may blow. Set the meter switch to A first and check the reading is below, say, 0.2A, then transfer to mA and VΩmA.

Good luck.
 
This doesn't look right, 0.26mA is unrealistically low. Looking at the first picture, it seems like you have the meter connected incorrectly. The meter is set to mA but the red lead is in the A, not the VΩmA socket. Take care, most meters have a protection fuse, so if your drain is above 200mA etc, the internal fuse may blow. Set the meter switch to A first and check the reading is below, say, 0.2A, then transfer to mA and VΩmA.

Good luck.
Thanks for that, I'll recheck at the weekend using the correct scale🙂. The SOC has gone down to 31% today but it still starts the same !
I can't see there being anything wrong with the truck as I wouldn't have thought it would start with a battery that low.
 
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