A look at the Bluetooth 4.0 Battery Monitor II
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What is Battery Monitor II? How does it work? App-based vehicle battery voltage monitor.
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I think the percentage for the alarm is going to be based on the state of charge, not the charge voltage, and in ways that is actually better, as a heavy load such as cranking would trigger the alarm warning due to the voltage drop that will occur, I think in general the SOC warning (if it actually works) would be better.
No it sucks because it doesn’t notify you when it reaches the values set. The best you can do is get it to notify you every hour. Who would even design something so badly? Live update or pointless device
I installed one of these on a car that had a solar charger in order to make sure that the battery was kept charged up during non use in the winter. The range was way less than 10 meters, more like 3 on a good day. It was good enough so when walking in front of the car the phone's bluetooth picked it up. Hope your unit works farther away then mine did. Happy holidays to all!
Happy Holidays to you and yours! *Cheers*
Almost a good product. Maybe we need to wait for version III.
The FCC ID printed on it is valid, and there is even internal pictures, no need to open it. and the two wires on each sides seems to be soldered on the same point.
Thanks, Julian :-) A tip: go for a Victron Smartshunt. Its a real coloumb counter, and you Get a lot more accurate readings :-) Marry Christmas from Norway!
At £120 that unit is six times the price of the reviewed.
@@gedtoon6451 yes 😊👍 But it can probably be bought and later sold used, and a better option when trying to analyse consumption.
If only they did these things to support higher voltages it would be a good cheap solution to monitor lithium batteries etc.
There are units made for lithium batteries. Look up the Antigravity AG-BTR-1. The Antigravity AG-BTR-2 is their lead acid battery model.
@@android04 Interesting looking device thank you 🙂
Are there OBD2 dongles with this? Some might actually tell you if the 12V DC-DC converter is running. Maybe Bjorn Nyland has tested one?
Hi Julian....yes heard you mention your V2L problem in this vid....just answered your question in one of your other vids . .sorry for delay forgot I had commented. ..
On my MG 4 it runs off V2L for long periods no problem....like 12 hours .... I am sat in my man shed typing this and I have been connected to v2L for 4 hours so far and the 12v batt voltage is showing as 13.9v in the ismart app so is obviously being kept topped up by the traction battery
Yours being a facelift ZS don't you too have the ismart app as in "vehicle status" it shows the 12 v batt voltage? Without need if a separate monitor
If yours doesn't charge the 12v while on V2L maybe there is a software update?...btw mine also provides V2L wether the car is locked or unlocked.. some have said theirs only works while unlocked
I suspect it doesn't want to trigger on a voltage because cranking on a cold day could cause the battery to fall for a short while, giving false notifications. If you then set it to stop that, you won't get a notification when the voltage has fallen for other reasons, the very ones you need to know about.
The bloke below made a good point what's all that custom stuff do and another bloke down below recons your bells are in the place clever lot down below today....Merry Christmas !
I had to charge my 12V battery in my corsa e EV, when I got in before the main battery was on it popped up economy mode enabled which means the 12V battery is a bit low.
If you choose custom battery at start, could you maybe set custom voltage warnings etc then?
Hi, Julian!!🙂
Another reason for setting alarms based on voltage is when a load is removed the voltage will rise which could give false confidence in the state of charge. The percentage of charge capacity is less likely to change. However, with a coulomb counter all the current must pass through the counter. Of course that's not a concern on an EV as there shouldn't be a lot of current draw. Well, not unless the wires to the door lock shorted out.
Why you didn't attach a variable power supply for testing the device on the bench?
Because it's a battery monitor, not a PSU monitor.
Maybe looking at the graph disables the notification. Why sending notification, when the user is looking at it?
You had the top trigger at 70% - that will only send a notification when CHARGING. The bottom trigger is the one you needed to set at 70% in order to get a notification sent while DIS-CHARGING. So to recap:
1. The bell to the left triggers when discharging
2. The bell to the right triggers when charging
I was just about to say exactly the same thing 👍
It’s dumb though because when my discharge reaches 60% (which is what I set the notification to) it still doesn’t notify me. The best you can do is have it notify you once per hour. It needs to notify you as soon as it hits 60% otherwise it is a stupid product
It would be strange for the 12V battery charger to be off while using Vehicle to Load since the contactors will need to be activated for V2L and they run off 12V. Sounds like a fault somewhere.
As for the unit your testing I suspect you could build better yourself.
Maybe it's draining the 12v battery to keep the contactors closed? Maybe it doesn't charge while that condition is true and so V2L has to be disabled before charging can be re-enabled.
The lack of an inline fuse makes me slightly nervous! Although I guess you'd need two :)
ETA: I guess you could argue that the gauge of wire used makes it functionally a fuse anyway!
Julian, did you measure the voltage accuracy of the device against a DVM? A few decimal points in battery voltage can be the difference in a battery having enough capacity to start the car (or not!).
I never knew an EV car has a regular 12V LA battery 🤷♂️
Every day a school day…
Does anyone know any battery shunt/coulomb counter that communicate over WiFi or Tuya/smarthome or Zigbee?
Could it be possible to connect to that Bluetooth device through one of those Arduino based serial-port bluetooth modules?
Why no characterise the % reading with a variable power supply and multimeter ?
How long would it take this thing to discharge the battery say 1 or 5%
Might be useful for my old Citroen diesel. We don't use it very much now we've got an EV, during the Summer we have a small solar panel that seems to keep the battery level OK but during the Winter it rapidly loses voltage. Perhaps I need a bigger solar panel. 😆
Yeah, from the point of view of solar, winter is a very different scenario :)
why normally vehicles don't have this installed from factory?
I need to mont. 3 Battires will it pick up 3 units??
There are projects which allow you to connect via bluetooth without the app.
Mind sharing? Would be neat if you could use an ESP32/8266 as a bluetooth bridge running ESPHome and integrate into Home Assistant.
how to query this device from raspberry pi ?
Hallo,
can you tell us about:
Arduino PLC
Kind Regards Rob ( NL )
Your problemis probably that the v-l function has a computer awake permanently and that computer is run from the 12vbattery and probably when the traction battery is at a certain SOC it will stop charging the 12v battery. When I worked at Mitsubishi we had this problem with the wifi/bluetooth computer on PHEV models because of a software bug that kept that module from going to sleep.
It's worse than that. V2L is fine when the car's electrics are switched on. Switch them off and the 12V battery isn't charged AT ALL. The contactors in the HV battery probably pull around 5A from the 12V battery so it drains down after just a few hours. It's very poor design.
@@JulianIlett Yes I agree with you there. I had the same problem on my mondeo whenthe diode bridge in the alternator was broken. That probably has a much bigger battery and it was usually dead over night and unreparably broken in a month. Is it an MG you have?
Why do you not use à variable power supply for testing this device ?
My thoughts exactly 😀
Julian thinks in digital!
Because it's a battery monitor, not a power supply monitor :)
@@JulianIlett But but... You can emulate battery conditions much faster to see how the software reacts🙂
@@JulianIlett lol
If this does not allow to set 0% and 100% voltage, then I would assume it will use 6V as 0% - not great. Hopefully it's 0% at 9V or higher, manual should state this.
maybe buy a jumpstarter or put the battery on trickle charge or would that bugger the EV🙂
This thing drains at 15mA which is too much for my likeing it drains my super capacitor bank too fast
I don't understand why EVs still need a lead acid battery all that modern technology why don't they have a transformer and run from the main battery. Cool video tho I may have to get one for my solar shed Shame it doesn't do 24v
Yes they do, once the EV car is "on". For Safety... the Open high voltage contactors physically isolate the high voltage battery when the car is "off". The contactors need a small amount of energy to close them when you turn on the car. Hence, a 12-volt battery provides that small amount of energy needed to close the high voltage contactors. Once they are closed, the high voltage battery takes over and supplies power to the 350 volt to 14.5 volt converter to the "12 volt system" which charges the 12-volt battery up and supplies power to the other low voltage systems when the car is "on". My EV monitors the 12-volt battery when the car is "off" and opens the contactors automatically when I am asleep if the 12-volt battery voltage drops below a certain value. It has settings that let me turn this feature on or off.
You need a proper electronic load so you can properly do these kinds of tests.
Waste of money! I bought three of these BM2 Battery Voltage Monitors so that I can check on my batteries of my stored/parked vehicles as well as my daily driver in my garage and driveway and I wanted to be able to check them while sitting in my home. The range is about 12 feet as I have to be at my front door to get a signal. This is typical of Bluetooth devices where they state 10 meters or 33 feet but in unobstructed view, but not under a hood shrouded in metal. If I need to be that close to a vehicle, I might as well pop the hood and take a DMM meter to the battery.
Had one for the camper battery and it would work them just stop working I had to keep removing it and putting it back on again to get the app to see it. Total junk IMO
I think Hyundai had a similar issue with their 12v battery draining to flat - it was fixed with a firmware update. Not sure it was related to VTL though
Seems mad to me that all the electronics are powered by the small 12V battery when kWs are available from the pack. Wouldn't a better design simply be to take pack voltage through a power supply to the electronics? I'm sure better minds than mine figured this wasn't a better solution
The MG is weird. The fan runs from the 12V battery - you can see the battery voltage fall quickly when the fan is on full whack. The seat heaters won't operate unless the HV battery is enabled. I can't imagine the seat heaters are more than a couple of hundred Watts each.
You would have thought the EV manufacturer would have included such a device to monitor the 12v etc in its electronics along with the rest of the electrics - you shouldn't have to buy a £20 add on........
12V battery voltage is visible in the instrument display, but only when the car is powered up. It's also displayed in the app, but it appears to be 0.6V too high. I wanted to see battery voltage when the car is completely switched off.
@@JulianIlettYpu can keep your eye on the battery level from the MG iSMART app - just need to press the ‘Vehicle status’ button from time to time to get a refresh - includes the ‘12 volt’ battery voltage.
If you use 2 wires to power the device and 2 wires to measure, it is just a 2 wire measurement.
It's rubbish then
Tell me WHY LOCATION needs to be turned ON for a more accurate reading. What BS! I always have my LOCATION turned off on my mobile phone. None of their effing business what my location is.
It is better to make an own device. This is useless.
There is no current monitoring and the firmware is not open source, so that people can modify it if something is missing or if there is a bug. This is the problem with this cheap Chinese hardware.
£20 bloody heck, more money than sense, what is the point of it. Oh you have an EV and use it to power house also you say lead acid I would expect you have AGM is there no condition on your car that can alarm if your car battery runs down during house powering from it??? if not shame about that not good for an EV is it
Ha ha - I have far less money than sense - well I think so. The car however is far less sensible and flattens its own 12V battery without so much as a whimper. That seems pretty dumb to me :)
@@JulianIlett That is also my problem has been for years less money than sense mind you it is a close call🙂
One thing's for sure - both are heading down, not up :)