Battery Monitoring -- How I Done It --

[mrdanielmh]

So there is no physical difference just the firmware?

 

[Dellmassive]

So there is no physical difference just the firmware?

Correct..

And the firmware is just the

Low,charge,ok, voltage data metric points....

So same as all other BM2 in regards to monitoring function and history logging.

Ie.... they all work exactly the same.

 

[mrdanielmh]

Ah i see! So it's only annoyong because the status shows as incorrect but the data is correct

 

[Ann3x]

Correct..

And the firmware is just the

Low,charge,ok, voltage data metric points....

So same as all other BM2 in regards to monitoring function and history logging.

Ie.... they all work exactly the same.

How did you buy the lithium version if its not for sale anywhere? Direct contact?

 

[Dellmassive]

How did you buy the lithium version if its not for sale anywhere? Direct contact?

Yes, as above. (direct import from china)

Here: Battery Monitoring -- How I Done It --

.

 

[catfood12]

@Dellmassive , thanks for another awesomely detailed and informative thread. I've just bought a BM2 from the 'Bay to try and get to the bottom of issues I have with my Cayenne. A new (water cooled 180A! OEM Hitachi) alternator and genuine AGM battery later at least the thing is now charging, but the new battery now keeps losing charge. I think it's a duff battery.

 

[catfood12]

Fully charged yesterday by a CTEK.....




Now as flat as a pre-lockdown pint of beer.

 

[widu13]

My BM2 is pessimistic too, it records 12.34v as Low Power in danger red, whilst most charts put this at 70% charge!

 

[Dellmassive]

@catfood12 Thank you, and I'm glad they have been a help to you.

Dont pay too much attention to the warnings & "low power" messages....

What's more important is the voltage measurement and the logging history.

For example an AGM battery may be 100% charged @ 12.6v but that's out the car on a test bench. As you soon as you connect the battery to a car the voltage will be a bit different.

The voltage will also drop when the car/van is powered up by say unlocking or opening a door...... all sorts of modules and pumps start running which will cause a drop in the voltage....

So you need to look at voltage the average and put it into context for that particular car/van.

So for your Car, is 12.0 low, does it still turn over and start?

When you charged it fully with your ctek did the BM2 readout over the next 24hrs show a gradual drop in voltage?

Does the voltage drop massively when you turn on the head lights?.

Let's see some 24hr screen shots and see what's going on.

 

[catfood12]

@catfood12 Thank you, and I'm glad they have been a help to you.

Dont pay too much attention to the warnings & "low power" messages....

What's more important is the voltage measurement and the logging history.

For example an AGM battery may be 100% charged @ 12.6v but that's out the car on a test bench. As you soon as you connect the battery to a car the voltage will be a bit different.

The voltage will also drop when the car/van is powered up by say unlocking or opening a door...... all sorts of modules and pumps start running which will cause a drop in the voltage....

So you need to look at voltage the average and put it into context for that particular car/van.

So for your Car, is 12.0 low, does it still turn over and start?

When you charged it fully with your ctek did the BM2 readout over the next 24hrs show a gradual drop in voltage?

Does the voltage drop massively when you turn on the head lights?.

Let's see some 24hr screen shots and see what's going on.

Thanks for the info @Dellmassive. All a great help.

The BM2 was delivered at midday today. These things are awesome. Imagine the kit needed to get that level of data logging alone, let alone presenting it in what is quite a well laid out app. All for £18.98 from the 'Bay. Astonishing.

Anyway, my Pork problems. The alternator was duff, 150K miles on a Cayenne V8 diesel, the regulator failed and was charging up to 16v, and of all things screwed the TMPS ECU. Sorry, no T6 content here.

I made some new brushes up, cut down from some Bosch ones, but they didn't help. The pattern spares availability is dubious, so I got a new OEM exchange alternator from the Germans. The biggest PITA is that the alternator is 180A, and is water cooled ! The engine cooling circuit goes through the alternator, albeit in smaller bore pipes. Secured by a single M6 bolt and pesky O rings. Every time I had the thing in and out, I had to drain and bleed the cooling system. That was the bit that was losing it's charm.

Fitted the new alternator, but the battery was fried. New OEM battery from TPS (same as Q7/Toerag etc), but whilst now regularly charging to exactly 14.8V, same as your T6 (reassuring to see from your thread), losing charge.

When I leave the car, draw is around 300mA, as the ECUs go to sleep after 20-30 mins, draw drops to 30-50mA, so it's not current draw or more fried electronics.

Battery coded when installed, by another mega £90 tool from the 'Bay that I've had some time, as even the domestic Durametric can't code Pork batteries, and it won't do it off VCDS.

It must be a duff battery. It has to be. It's been on a CTEK all afternoon;





It's just making sure that the battery is a fault. I might swap it with a battery from my wife's car. I thought I had finished swapping batteries from other cars back in the 90s... They have a mahoosive battery, AGM for start stop as OEM, although the first thing I ever did was disable start stop....

 

[Garny999]

They are not selling the lithium FW version openly.

It's just the one BM2 everywhere.

Not even sure if the will.

It's the same thing anyway...

Just received and fitted mine. To be honest, I am quite dissapointed. All I wanted was a percentage scale of charge but all I get on my Lithium setup is the voltage of the battery....and charging??. Perhaps need something that is actually set up for Lithium and will give me a percentage reading.

 

[Dellmassive]

Just received and fitted mine. To be honest, I am quite dissapointed. All I wanted was a percentage scale of charge but all I get on my Lithium setup is the voltage of the battery....and charging??. Perhaps need something that is actually set up for Lithium and will give me a percentage reading.

Lithium batteries hold there voltage for 90% of the capacity, so you need a current-shunt style monitor.

so for these batteries you need one with a built in monitoring or a shunt monitor.

I've detailed some over here :

Battery Monitoring -- How I Done It --

Battery Monitoring -- How I Done It -- Part #1 Battery monitoring is a very important part of your 12v system . . . . whether its just the vans starter battery or your leisure setup keeping an eye on the power in your battery bank will keep you from breaking down and make sure your weekends...

www.t6forum.com

the best option would be the new Victron Smart Shunt, shown over here :

Battery Monitoring -- How I Done It --

Battery Monitoring -- How I Done It -- Part #1 Battery monitoring is a very important part of your 12v system . . . . whether its just the vans starter battery or your leisure setup keeping an eye on the power in your battery bank will keep you from breaking down and make sure your weekends...

www.t6forum.com

********************


The BM2 will only give you a voltage reading, which is still helpful.

but for Lithium capacity you need a different style of monitor.


@Garny999 which Lithium have you got?

 

[Garny999]

Lithium batteries hold there voltage for 90% of the capacity, so you need a current-shunt style monitor.

so for these batteries you need one with a built in monitoring or a shunt monitor.

I've detailed some over here :

Battery Monitoring -- How I Done It --

Battery Monitoring -- How I Done It -- Part #1 Battery monitoring is a very important part of your 12v system . . . . whether its just the vans starter battery or your leisure setup keeping an eye on the power in your battery bank will keep you from breaking down and make sure your weekends...

www.t6forum.com

the best option would be the new Victron Smart Shunt, shown over here :

Battery Monitoring -- How I Done It --

Battery Monitoring -- How I Done It -- Part #1 Battery monitoring is a very important part of your 12v system . . . . whether its just the vans starter battery or your leisure setup keeping an eye on the power in your battery bank will keep you from breaking down and make sure your weekends...

www.t6forum.com

********************


The BM2 will only give you a voltage reading, which is still helpful.

but for Lithium capacity you need a different style of monitor.


@Garny999 which Lithium have you got?

Many thanks @Dellmassive still confused lol. I have the TN Power 100 and just need ( sorry, but cheap ) monitor that tells me when i need to consider recharging which I thought this may have done but not good. I get that you could look at the voltage but as you state in previous comments, it doesnt work efficiently with lithium, thanks again though pal.

 

[Dellmassive]

Bm3...... but paid for???

Not sure bout that.





....


@mmi link from above in thread. (Free)

BM3 APK for Android Download

BM3 2.0 APK download for Android. can manage multiple 12V, 24V,48V batteries ,as well as solar battery.

m.apkpure.com

.

 

[Dellmassive]

Battery Monitoring related info:

just checked on the Renogy DC-DC (has an ignition feed)

same thing is happening here.

The starter is on EHU Victron 12v/15A charger, which is charging the starter battery.

The Renogy DC-DC is seeing the raised starter voltage and indicating the ALTERNATOR is running (even with IGN OFF)

The Renogy has started charging the Leisure battery.


Seems this is a feature of most modern DC-DC chargers . . . that even when they have the IGN/BCM RUN feed connected and switch off. They will startup when the starter battery voltage is high enough.


So with either EHU charger OR a solar charger connected to the tarter battery, both can be charged via the DC-DC


NO EHU, battery Low.

.

And ALT shown as OFF.

Then EHU connected to starter . . .

DC-DC now shows ALT power . . .

..

Victron shows 8A going to starter.

starter shows voltage increase. . . .

BMV shows 3.2A going to AUX battery via DC-DC . . .

and AUX battery shows a voltage increase.

Happy dayz . . . .



*******************************************************************************


Edit:

here is the 24hr BM2 BM3 readouts showing the effect of the EHU connected to the starter battery . . . . . . which is inturn charging the AUX battery via the DC-DC "Auto VSR mode"


we started off as above, with a 100% charged battery. so after 24hrs is i switched off the EHU (Victron 12v/15A bluesmart charger)

this is the Starter battery readout :

and the BM2 24hr readout:

you can see the Bulk, absorb and float/storage stage in the readings. . . . .

at 10am the folowing day when switched off you can see the drop back to the static battery volasteg.



Next up was the AUX battery . . . .

here is the AUX 24hr readout.

This had NO EHU connected , , , , just the DC-DC,

again you can see the Bulk,Abs,Float stages in effect. . . . . untill about 2am when the DC-DC stops charging.

.

.

next up is the combined data on the BM3 app.

.

test procedure:

EHU connected to starter battery at 11:30am day one.
EHU disconected at 10AM daytwo.

Current DC-DC charger : Renogy DC50mppt. (no solar connected)

This shows that as many other DC-DC chargers they work as a "Auto VSR" and will Auto-start when the starter battery is raised high enough.

*******************************************************************

 

[Big.mac]

And the Apple version is a pound more expensive!

 

[Big.mac]

Battery Monitoring related info:

just checked on the Renogy DC-DC (has an ignition feed)

same thing is happening here.

The starter is on EHU Victron 12v/15A charger, which is charging the starter battery.

The Renogy DC-DC is seeing the raised starter voltage and indicating the ALTERNATOR is running (even with IGN OFF)

The Renogy has started charging the Leisure battery.


Seems this is a feature of most modern DC-DC chargers . . . that even when they have the IGN/BCM RUN feed connected and switch off. They will startup when the starter battery voltage is high enough.


So with either EHU charger OR a solar charger connected to the tarter battery, both can be charged via the DC-DC


NO EHU, battery Low.

.

And ALT shown as OFF.

Then EHU connected to starter . . .

DC-DC now shows ALT power . . .

..

Victron shows 8A going to starter.

starter shows voltage increase. . . .

BMV shows 3.2A going to AUX battery via DC-DC . . .

and AUX battery shows a voltage increase.

Happy dayz . . . .

I’ve noticed the same thing on my CTEK. If I connect an external charger to the starter battery, the DC-DC kicks in and it’s charges leisure battery at the same time. I scratched my head over this for a while and came to the conclusion that the IGN feed to the CTEK is to override a low voltage from the starter battery when the engine is running rather than to turn on the DC-DC.

I think the way it works is the DC-DC will charge based on the voltage it detects on the starter. Because a smart alternator vehicle will allow the voltage to drop lower than a standard alternator there are likely to be situations when the DC-DC would not charge if purely based on the voltage detected. So, it has an override which forces a charge when the ignition is on. This in turn makes the voltage drop on the starter battery which won’t be a problem if the engine is running as the alternator will then kick in.

When connecting an external charger to the starter battery, the DC-DC detects the higher voltage and kicks in....

I don’t know for sure this is how it works but this is how my brain worked it through. Happy to be corrected.

 

[Dellmassive]

I’ve noticed the same thing on my CTEK. If I connect an external charger to the starter battery, the DC-DC kicks in and it’s charges leisure battery at the same time. I scratched my head over this for a while and came to the conclusion that the IGN feed to the CTEK is to override a low voltage from the starter battery when the engine is running rather than to turn on the DC-DC.

I think the way it works is the DC-DC will charge based on the voltage it detects on the starter. Because a smart alternator vehicle will allow the voltage to drop lower than a standard alternator there are likely to be situations when the DC-DC would not charge if purely based on the voltage detected. So, it has an override which forces a charge when the ignition is on. This in turn makes the voltage drop on the starter battery which won’t be a problem if the engine is running as the alternator will then kick in.

When connecting an external charger to the starter battery, the DC-DC detects the higher voltage and kicks in....

I don’t know for sure this is how it works but this is how my brain worked it through. Happy to be corrected.

No, agreed. I think the same.

And the testing seems to agree too.

 

[catfood12]

Bm3...... but paid for???

Not sure bout that.

View attachment 68307View attachment 68308View attachment 68309



....


@mmi link from above in thread. (Free)

BM3 APK for Android Download

BM3 2.0 APK download for Android. can manage multiple 12V, 24V,48V batteries ,as well as solar battery.

m.apkpure.com

.

That link for free BM3 from APK pure works a treat.

 

[Dellmassive]

Additional BM2 & BM3 data added to above post (using EHU to charge Aux via DC-DC)