Sharing.....

I saw inUtube about this product.
Locally I can get it, very cheap at US$20 max.

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This will be good to have since it can monitor a few parameters.

I don't trust the SOC ( state of charge ) value, but it is not important for me.
What I need is its logging per 2 minutes and it can log up to 2+ months or so.
Therefore I do not need to use my DMM to measure my battery.
For those who loves to lock his car at home ( mine never locked at home ) , when you open the door to open the hood lock, you will consume power,
with this all you need is to use the bluetooth apps.

I have not tested its cranking test feature but it can be some sort of baseline for us.
1 data point per 2 minutes is not good enough to catch fast voltage drop while in driving mode.

Blue highlight is me testing it using my bench-power supply at 13.05V and then later I use 12.72V.
Yellow is the BM200 already installed on my battery.



Below is from the car battery

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The Y shape battery connector is a bit too wide if for W212 standard bolt M10.


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Make sure you tighten the M10 bolt hard till it stop.
The Y connector will then bend into shape and only then allow for true tightening of the M10 bolt for the battery clamping....shake hard battery terminal clamp to make sure it is proper tight to battery post.

I use those clear vinly tape to secure the cable to sit well on the battery. If you want pretty without fingerprint on the tape, I think pincher/tweezer tool holding the tape for cutting may work.




Its operational power consumption of 1.5 mA is lower than W212 deep sleep power consumption...which if mine is 5 mA.
It will be double or 3 ish milliamps when the bluertooth is in connection with your tablet/smartphone.
Hood closed, engine OFF, I can still communicate with BM200 from 3+ meters away.




User manual :
https://www.anceltech.com/Public/Upl...90c3ed9faf.pdf


Its voltage accuracy is good.




Temperature sensor, so so. But good enough +-1.5C




Happy shopping..........

 

There must be more hours in a day on the west side of the Pacific.
I don't know how you do it, but I'm glad you do. The detailed knowledge and experience you post up on these pages is invaluable.

 

I'm putting one of those on my zero turn mower. It seems to be having intermittent battery problems

 

I am 95% retired, thus plenty of time to spend my love for the car

I am glad the post is useful to you.

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Here is more user information :

01. There is no log data delete feature. So I guess oldest data be removed automatically when the memory is full.


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30 days seems to be the maximum capacity.
1 data point per 2 minutes = 720 data points per 24 hours
720 x 30 days = 21,600 data points.

So by day 25-29, save the data to your tablet/smartphone

I send via WA from my tablet to my phone.



The log file in CSV, at times is not very updated in comparison to the time I sent it via WA.
Example 8:57AM file, which by right should be missing only 2 minutes data point or 4 minutes late at the most, thus its latest daat should be 8:53 AM.
Instead I only got up to 8:41, like 15 minutes or 7 data points too late.




I tried again downloading the log file at 9:03 AM, this time I loose only 2 data points or 4 minutes. 1 data point or 2 minutes is always lost or not updated enough by the time file downloaded.



The file keeping is per 1 day 1 set of column A to D and next day next 1 set of new column F to I, E is spacing.... its nice.




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Deep sleep mode and charging logging test.
Note : Due to me doing IGNITION-ON ENGINE OFF, the deep sleep of the modules become 6 hours and not the usual 15 minutes when car Ignition been OFF for more than 6 hours.

ABOVE is 6 Oct 2025 full log :
Zone 1 is bench testing the BM200 using power supply.
Zone 2 is BM200 installed and allow to run.
Zone 3 is me unlocking the door ( it was locked ), turn ON ignition to flip close my mirror and close the door. Here the modules woke up and needed 6 hours to go to deep sleep.
Deep Sleep is defined when K2 relay at F32 Prefuse is OFF.

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BELOW is 7th Oct 2015, starts at 00:01 AM
Zone 3 is continuation of 6th Oct Zone 3. Here I realized after waiting for like almosy 4 hours, the K2 relay did not turned OFF.
So I charged the battery using Ctek 5.0, that is Zone 4 and 5.
Zone 4 is the bulk charge at 4 amps to 1.5 amps.
Zone 5 is the absorption charge and the dip back to battery voltage 12.8V is Ctek turning off charging and doing its math and proceed to Zone 6.
Zone 6 is Ctek doing float charge.
Zone 7 is when I removed the Ctek charger.
I never realized Ctek turning off charging and doing its math and proceed to Zone 6, because I never logged this long during Ctek charging. Nice.
Since my battery is quite full, Zone 4 is short duration, only 2 hours. Zone 4 is where the Ctek LEDs the #3 to /and #4 lighted up.





Because battery is full and load is 6.5 milliamps only during car modules deep sleep and BM200 own power consumption,
the surface voltage is still high at 13.04V after charger removal.





I will be away 8th to 21st Oct at sea on 10-19 Oct, thus this logging would be good to have.
Every 7 days or on Sunday, my man will charge the car as part of SOP when I am away.
When I return, I shall update. Those charging will be shown on the log for sure.

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I did not manage to log my battery during me being away.
I disconnected the battery because I removed the ECM for cloning.
8th to 24th Oct up to 5 PM ish, BM200 was disconnected.
It was fully charged when disconnected on 8th Oct.

On 24th Oct , about 8PM ish.... I charged my battery using Ctek because I was testing the new cloned ECM.
I have not driven my car out of the garage yet.

All I can say is, do not worry or trust the SOC ( state of charge ) level.
Simply use the voltage of the battery as reference.
Here is 5 hours after I charged the battery, SOC is 90%, it should be close to 100%




Battery voltage reading is to be taken while car is in deep sleep and fob key as far away as possible.


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The so called TRIP REPORT, it got fooled by battery charging using Ctek...LOL
It also failed to recognize that I run my engine twice and not once, but the time between engine kill 1 to start of engine 2nd time was only a few seconds apart.


If you see above 6 minute TRIP TIME on Oct 2025 2:05AM in the morning, that is Ctek reducing voltage after bulk charge of 3 hours 48 minute stated as 01:49AM of 25th Oct 2025.
The 7hours 52 minute is the Ctek doing float charge, until I power down the Ctek at 10:01 AM 25th Oct 2025.

As for Start and End Location, the Apps take positioning data of the GPS in my tablet, which at that point in time 7th Oct I purposely find clear sky to get GPS running.
The rest of the data of Oct 24th to 25th which has no positioning data, my GPS in my tablet was not getting clear sky in my garage, thus no data.

I then called a friend whom I told to buy the BM200 too and get his log data.
One of the car is Toyota Alphard. The clock was still UTC and not yet adjusted to +7 UTC Jakarta city is for time zone. This could be a glitch depending on what smartphone is being used.


Here I am guessing and I think I am correct, the BM200 Apps on his smartphone is working behind the scene, even when not being operated.
I said this is because the GPS location change shows the car did travel from A to B to C away from home and some data is basically his garage location.
So when you have a mistress, don't let your wife download this data from your BM200 ....LOL

Bottom line is the Trip report is quite USELESS, but its GPS data is as good as your smartphone being with you.
I do not allow any apps of this sort on my primary smartphone. I use tablet/s for it or similar apps and the tablet/s does not come with me on any drive, unless I need to bring it.


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So far the engine cranking data for my E400 is good


3X comp test Xentry is Compression test and it is battery maintainer assisted.
The cranking time seems accurate, the voltage dip is decent.


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To monitor devices load, the BM200 is good.
Here I am seeing my friend's Toyota Alphard which has aftermarket front and rear dashcam, which I believe is hardwired not to ignition switch 1-accesories, but to always HOT/Power connection.
3 days worth of drain. It could be that the dashcam is set to parking mode.




I will share more when I find out more.

For the time being it seems some smartphone may not send its real local time info to the Apps.
My friend's data is based on UTC time and not UTC +7 the local time is.
My data is already UTC +7 time.

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Information update :
The Apps only track position when it is activated ( turned ON ).

Here my friend never bothered to turn the Apps On when he is using his Toyota Fortuner


The clock is OK, it followed smartphone time.


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For diesel Land Cruiser 300, glow plug activation sucking in power, is calculated as cranking duration ...LOL
I wonder what low voltage is deemed as "cranking" voltage by BM200 ?


This LC300 engine does not crank -to-start for more than 1 second, engine will start. So those 2ish to 3ish seconds are the glow plugs and then cranking.
Learning something new everytime....nice.

 

I bought one of these when I had the red battery warning popping up and wanted to see if it was a charging issue. Very handy for seeing real time voltage while driving around.

When I installed the app on my current cell phone it wanted all types of permissions and access so instead I use an old cell phone that is no longer connected.

Im not sure how accurate the SOC is since unlike my other inexpensive battery tester this one wont allow me to input what type of battery and CCA it is, least i dont think it does.

 

True SOC is very complicated to calculate.
Current clamp sensor must be involved, battery true profile/amperage/type and etc must be known to the controller.
Those off grid houses with solar panels and battery storage have advance components to calculate their battery bank SOC.

Some long range sailing yachts I know have very complicated battery monitoring system too, since they only turn ON their main engines when needing to charge the battery bank or add speed
to the sail system. Crazy big batteries, 2V cells type ( most robust) during the days Lit-ion does not yet exist for yachts. Between 2,000+ amps at 12V is very common.

The BM200 for its price and its wireless bluetooth is good enough for me as casual convenience monitoring.
In fact due to the BM200, two of my friends cars the Toyota Land Cruiser 300 and the Toyota Alphard will need me to measure its sleep mode load to confirm if
any excessive drain coming from a wrong power source dashcam or perhaps other Totoya own modules not sleeping in deep sleep mode.

or....

Simply these two cars batteries is going weak. I will test their reserve capacity/minutes and see what's going on.

This is from his oldie 2013Toyota Fortuner which has very very little electronics and got a new battery.




Some software glitch, data jump or data loss.



Other days with data loss



Toyota alphard, data loss is much less



Very little data loss from Land Cruiser 300



I think the build quality of the BM200, some so-so, some good
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I might getting one of these also. Btw, is there any portable version which able to measure the current flow hmmm.

i just intalled hella AGM battery on my w212 replacing my 10 month old amaron EfB, but the voltage drop after installing it is quite massive. Thinking my old battery maybe still have some life left on it )

Before installing my hella battery figure according to lancel micro 500 battery tester
795 CCA
12.84 V
3.11 m ohm resistance

after install in the car
850 CCA
12.56 V
2.89 m ohm resistance

Putting the key in ACC position and check the UB and IB value its 12.4v with IB -10 to -15A

is this normal?

the battery

before installing the car, about 12 hour after charging with ctek in AGM mode.

after installing in the car

 

^^^ On the tester screen it shows CCA but on the battery is lists EN. I really dont know what the difference is. Does you tester have the option to pick battery type? My battery tester has a few different options.

I recently replaced my battery. The old Genuine MB battery lasted me 5yrs until it went dead not holding a charge. I think the issue was that it wasnt healthy when I installed it, I failed to notice the MB dealer sold me a battery that was already 1.5yrs old based on the manufacture date. lesson learned.

The new battery I went with an Everstart H7 AGM from Walmart. I wrote a thread all about it: https://mbworld.org/forums/c-class-w...sted-5yrs.html

I bought the battery 3/26 and the sticker on the battery says 3/26 so im assuming its as fresh as they come. I've been to that store afterwards and they were sold out the next time and then last time they were restocked so seems they sell quick there.

I checked the battery with a multimeter when I got it home and it showed 12.85v. I put it on my battery charger anyways and got it up to 13.26v. Let it rest over night and it was at 13.02v.

Hooked it up to one of my inexpensive battery testers and it looked great. The old battery said replace. It was nice to see the battery monitor appearing fairly accurate.

 

ah yes, I thought it was the same EN vs CCA. I will retest later perhaps it will dropped down to closer 800 figure.

 

Question 1 : Btw, is there any portable version which able to measure the current flow hmmm.
Nope, the smallest you can find is the car original Hyundai Mobis baby sized module at the negative battery cable.......which is not ready to use for us.
Any inline amperage sensor must be able to withstand cranking amperage of the starter too, that meant it will be big an at least 500amps class. It will use a SHUNT.
BTW Hyundai Mobis can only read 102 amps or so maximum, here : https://mbworld.org/forums/e-class-w...02-4-amps.html

This is a shunt ( amperage sensor )


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Question 2 : Putting the key in ACC position and check the UB and IB value its 12.4v with IB -10 to -15A............is this normal?
12.4V with load of approx 11-15 amps is normal voltage drop even for healthy battery.