Battery Monitoring -- How I Done It --

[TallPaul_S]

Bought myself a BM2 as my caravelle sits on the drive doing few miles, and the battery has gotten low a couple of times in the last few weeks.

After connecting I gave the battery a charge so that it was at 100%, victron charger went to float after about 30 minutes to indicate it was fully charged, then on removing the charger and letting it sit for a while, it seemed to level out at about 12.4v.



Engine not ignition had been turned on at this stage, does seem ok? Going by the chart that seems to be around 75% soc which doesn't seem great. It's a 2018 van and I'm pretty sure it's the original battery so it's probably due for replacement soon.

 

[Dellmassive]

Bought myself a BM2 as my caravelle sits on the drive doing few miles, and the battery has gotten low a couple of times in the last few weeks.

After connecting I have the battery a charge so what it was at 100%, victron charger quickly went to float to indicate it was fully charged, then on removing the charger and letting it sit for a while, it seemed to level out at about 12.4v.

View attachment 227413

Engine not ignition had been turned on at this stage, does seem ok? Going by the chart that seems to be around 75% soc which doesn't seem great. It's a 2018 van and I'm pretty sure it's the original battery so it's probably due for replacement soon.

looks good. .

when you have a weeks or more data post a 7day plot.. .

that will show you the rate if decline,

and the average resting voltage. . .

if it stays above 12.0v you are good.

eg:

...

 

[TallPaul_S]

Ok good, cheers.

I've got electric sliding doors and have been using them quite a lot with me building my kitchen pod in the van, so that will probably add to the drain. I'll keep an eye on it and post a log. I'm out for a short trip to the train station tomorrow morning (7 mile round trip) and then into work on Thursday (11 miles each way, about 30 mins average) which is pretty much my typical mileage at the moment!

Oh and I took off my C Pillar trim as I'm going to get a BMV-712 at some point for the LB, I want to mount it on the drivers side C pillar behind the sliding door (which will be above my kitchen) but I don't think there's enough space for it with the cable attached, so I'll look for a surface mount pod.

 

[Mick]

Ok good, cheers.

I've got electric sliding doors and have been using them quite a lot with me building my kitchen pod in the van, so that will probably add to the drain. I'll keep an eye on it and post a log. I'm out for a short trip to the train station tomorrow morning (7 mile round trip) and then into work on Thursday (11 miles each way, about 30 mins average) which is pretty much my typical mileage at the moment!

Oh and I took off my C Pillar trim as I'm going to get a BMV-712 at some point for the LB, I want to mount it on the drivers side C pillar behind the sliding door (which will be above my kitchen) but I don't think there's enough space for it with the cable attached, so I'll look for a surface mount pod.

I’ve had mine for 6 years and the battery for 7. That’s about normal for mine. It drops to between 12%& 15% over 3 days.

As @Dellmassive said get yourself the 7 day trend. I have my EHU plugged in on a smart plug with 2 hours charging every other night. Keeps it nicely topped up.

 

[TallPaul_S]

Looking good so far, the lowest It got to was 12.25v. interestingly, it now seems to think that 12.4v is ok and is 76% SOC. I'm guessing it's calibrating.

 

[Dellmassive]

looks like MM has white boxed the BM6.

they even QR code you to the QuickLynX BM6 App. . .


same BM6 - Different sticker.





...

Full product description​

The Clarke CBBT1 (BM6) is a small pocket-sized battery monitor/tester, capable of displaying battery power, voltage and temperature on a mobile device via the app (downloadable from Apple Store or Google Play Store).
MAIN FUNCTION DESCRIPTION
1. Real-time display of battery power, temperature and voltage.
2. Automatically tests the starting and charging systems of the vehicle.
3. Sends alarm notification if the battery is abnormal.
4. App supports multi-device connection, 4 devices can be monitored at the same time.
5. Records the track, cost and driving habits of each trip which can be exported to an Excel file.
6. Records the last known parking position automatically and provides a car finder function through navigation. Please note that this is not a live tracking function.
7. Stores historical data (voltage, charge percentage and temperature) in the device for up to 30 days. Saves the data every 2 minutes.
8. Save unlimited historical data within the app.
Please see the comprehensive manual to discover the full potential of this device.
*Compatible with 12V Lead Acid Batteries: WET, MF, EFB, AGM, GEL, VRLA, Lead Calcium, SLA, 12V LiFePO4




...


or get a SEALEY BT2020 version here cheaper - LOl . .

https://amzn.to/42wqeyV

.

 

[TallPaul_S]

A wee update on my starter battery monitoring, all looking good.

The van was sat for 9 straight days with just some door opening, and over 2 weeks with just 2x trips of a few miles to train station, and 2x commutes to work and back equalling about 1hr, it never went below 12.18v.

 

[TallPaul_S]

I've just ordered a Renogy Battery Shunt 300 (using your discount code @Dellmassive for a few extra quid off) as I'm eventually looking at going down the Renogy route with a DC-DC charger, and One Core fancy screen.

Renogy Battery Shunt 300

Explore Renogy's trusted solar panels, lithium batteries, inverters, and off-grid solutions for home backup, RVs, outdoor activities, and sustainable energy in the UK. Achieve energy independence with premium products and expert guidance.

uk.renogy.com

However, there's a few things I wanted to check/test with regards the Renogy monitoring solution with the DC home app and/or the One Core, so I'll be able to do that once I've got the shunt and fitted it.

There was an update not long ago which enabled the battery percentage on the app and One Core main screen (previously it only showed with a Renogy battery connected). Without this, it's functionality is a bit limited. The other thing I want to test is when charging, and seeing what the battery percentage shows as. I've seen reports that it jumps to 100% regardless of the SOC, when the volts coming into the battery are at charging levels.

I just need to work out how to attach all these negatives to the shunt! I might go down the bus bar route, tbh I was eventually going that route anyway...

 

[roadtripper]

Yep for any shunt type monitoring you need to make sure all current flow in our out goes through the shunt. Either terminal would work but the negative is usually used as the positive tends to have main fuses and distribution on it.

A proper shunt shouldn't jump to 100% on charge as it has no way of knowing the voltage, all it has is the fractional voltage drop across the shunt it uses to measure current.

Monitors that infer SoC from tracking voltage can do this, or maybe if you have a system where data is coming from several sources something estimating SoC from voltage is incorrectly prioritised over the shunt data...? Shouldn't be the case because logging current in and out over a shunt is the gold standard, that's why the BCM does it on the van.

 

[TallPaul_S]

Yeah I agree, it might have been someone with just the DC-DC charger or some other set up, but tbh that's why I want to test and the shunt with the DC home app is the quickest and cheapest way to do that. I've done so much googling and looking up stuff that I can't remember where I saw it!

I'll get a couple of cables to go from the battery to shunt and shunt to busbar then mount all those negatives to the busbar.

 

[TheBops]

I just fitted a BM2 today as we've had battery problems in the past (that the dealer blamed on our split CTEK D250SE charge). The dealer put in a new EFB starter battery 6 months ago and just recently I noticed it was struggling to start the engine again and so I decided to fit the monitor. I have attached some screenshots from the app which shows it failing both tests, so wanted to get opinions here on what my next steps should be? I was only able to attach the negative connection of the BM2 to the van chassis, as the battery terminal has no space to allow me to fit the BM2 connection, so not sure if that helps explain the results.

Before I got the monitor I had been testing the battery each day with a multimeter and could see that the starter battery had been creeping up in voltage due to the solar panel having filled the leisure battery and had now started charging the starter battery, so it feels like the split charge is doing its job properly. So why a cranking voltage of 8.86v and a charging voltage of 12.05v in high RPM? Is this just the oddity of the smarts in the T6.1 or do I have a bigger issue? Generally the battery when the van is not running sits at around 12.5v

 

[Dellmassive]

I just fitted a BM2 today as we've had battery problems in the past (that the dealer blamed on our split CTEK D250SE charge). The dealer put in a new EFB starter battery 6 months ago and just recently I noticed it was struggling to start the engine again and so I decided to fit the monitor. I have attached some screenshots from the app which shows it failing both tests, so wanted to get opinions here on what my next steps should be? I was only able to attach the negative connection of the BM2 to the van chassis, as the battery terminal has no space to allow me to fit the BM2 connection, so not sure if that helps explain the results.

Before I got the monitor I had been testing the battery each day with a multimeter and could see that the starter battery had been creeping up in voltage due to the solar panel having filled the leisure battery and had now started charging the starter battery, so it feels like the split charge is doing its job properly. So why a cranking voltage of 8.86v and a charging voltage of 12.05v in high RPM? Is this just the oddity of the smarts in the T6.1 or do I have a bigger issue? Generally the battery when the van is not running sits at around 12.5v

View attachment 233618

View attachment 233619

Don't worry about the daily readouts.

You need to look at the 7and 15days plots to see the drop in voltage over time.

So use the van like normal and post a 7day plot...
. Then a 15fay plot

 

[TallPaul_S]

I don't think those tests on the BM2 are that accurate. Mine is 8.9v or 8.3v for the cranking test, but my starter battery is fine.

What's the voltage plots show over a long period, IE a week? And does the bank get used daily or does it sit for a while?

 

[TheBops]

Thanks both

We tend to only really use the van on weekends, but then it does get a decent run. It was last used on Sunday and did >2 hours driving including a fair bit of motorway. Will post back here in a couple of weeks once we've got some more data

 

[TallPaul_S]

Thanks both

We tend to only really use the van on weekends, but then it does get a decent run. It was last used on Sunday and did >2 hours driving including a fair bit of motorway. Will post back here in a couple of weeks once we've got some more data

Mine gets less than that at the moment!

This is a 2 week graph on mine, it was last driven on Tuesday last week (2 short trips) and current voltage is 12.08v.



If you have a look at my other posts above, you'll see it lasts nearly 2 weeks before needing any charging.

If you've got solar topping up the SB then you shouldn't be having any issues after a week of not driving it, so you might have another issue going on. A week's worth of graphs will tell us if the battery drain is normal or not.

 

[Dellmassive]

Thanks both

We tend to only really use the van on weekends, but then it does get a decent run. It was last used on Sunday and did >2 hours driving including a fair bit of motorway. Will post back here in a couple of weeks once we've got some more data

Post a pic of the starter battery terminals as well... Just for good measure.

 

[TallPaul_S]

My Renogy Battery Shunt 300 has been delivered.

I'm waiting on some bits to make up the cables to mount it, should get it fitted this weekend.






The plastic covers are held on with either self tapping screws or just small clips, but you don't get covers with other shunts so can't complain. Otherwise, looks decent - big M10 studs for the battery cables.

 

[TallPaul_S]

Just fitted the Renogy Shunt after I'd finished work, while it was still light.

Moved the negatives and chassis ground to an M6 distribution post, and fitted a new battery negative post mount with an M8 stud.



Worked out the best position for the Shunt, then made up 2x 35mm² negative cables


Then attached it all together - the shunt isn't mounted at present - I ran out of light.




Chassis ground is to the seat base stud. Seems to be reporting a correct voltage of 12.38v - and when plugging in my phone to charge it was showing 9w or so consumption.

I've manually synced the SOC to 75%.


With my phone plugged in

And with nothing plugged in


I'll plug the van in tomorrow and get the LB up to 100% SOC, at the moment I'm a little underwhelmed. There's very little functionality in the app, no SOC/time remaining on the main DC home screen. Maybe this will show up once the battery has charged/synced etc. or possibly that's only an option on the One Core screen.

I'll finish off the install tomorrow - mount the shunt and put some covers on the battery terminals, and put the seat back on.

The Bluetooth range on it is VERY good though, my van is parked on the drive and inside the house I can still connect when I'm halfway to the back door! The BM2, I have to be standing next to the van, and the Victron stuff I can JUST get a signal inside if my phone is by the window.

 

[TallPaul_S]

These are the depth of the settings available:

You can set the capacity of your battery, and manually sync the SOC to anything between 0-100%

These are the alarms that can be set

And the last page which has just the serial number, an option to reset historical data, and the current firmware (no option to update).

 

[TheBops]

Mine gets less than that at the moment!

This is a 2 week graph on mine, it was last driven on Tuesday last week (2 short trips) and current voltage is 12.08v.

View attachment 233630

If you have a look at my other posts above, you'll see it lasts nearly 2 weeks before needing any charging.

If you've got solar topping up the SB then you shouldn't be having any issues after a week of not driving it, so you might have another issue going on. A week's worth of graphs will tell us if the battery drain is normal or not.

Had the monitor on for the past couple of weeks and so far the battery seems to be behaving itself. Posting a 2 week graph here in case it points to anything, but to my untrained eye it looks fine