NASA BM-1 Bluetooth review

[MattBW]

I will add to this as I use it more. Obviously with the beach having no control panel there is no easy means to view the battery capacity or charge/discharge status.
You can use a volt meter for a rough idea but for effective battery management I want to understand amps too.

I looked at the victron Bmv 700 but wasn't sure if it would fit in the seat base without hitting the leisure battery. A Bluetooth setup also wasn't possible without the bmv 700 and would have been £175 for the kit. The app looks slick and well thought out but I went for the NASA as no screen was required at all.

The monitor is a small lightweight box and a 100amp shunt it has no screen so is reliant on your phone or tablet to get a read.

Wiring it up was very simple as the shunt comes with a wiring harness the most difficult part was accessing the battery in the beach. I did have to strip the wires in the wiring so they could be attached to the monitor and locked in place with screws. You will need wire strippers. You then put some load on the battery for a few minutes as it figures out your setup. I popped all the lights on.

So first annoyance, the iPhone app is £9.99 but the android one is free. This is apparently because iPhone app has more features. I will try and install the app on my girlfriend's phone later to compare.

First impression is wow it's ugly! Like something from the internet of the 90s.

You click connect and it almost immediately showed me the monitor and I selected it. You can update your battery name and amp rating and the click update. You then have 15 seconds to get the load data button on the device to update the monitor.

That said all of the information is there.

You can see charge or discharge status the condition of the battery (this has improved over the past day) and voltage. So when my solar is connected or i am on hookup I can visibly see how much is going in (or out). Handy to decide if I need hookup (or a bigger panel) ;-)

There are also some graphs available over time. Handy to see but the interface isn't very good. You literally have to hold your finger on the graph for the info to show which is awkward. You can't slide along either that scrolls to the next graph.

The BM-1 Bluetooth can also monitor your engine battery (voltage only) at the same time but for that I need to figure out how to get a wire to the engine bay. Maybe another day.

Range of the low power bt is quite limited probably 4 or 5 metres certainly not possible from inside my house.

Conclusion:

Provides all the info I need albeit in an ugly way that isn't the most user friendly. That probably doesnt matter as no-one else will see it (although anyone with the app can connect to it) If I was sure that a physical gauge would fit without hitting the battery I would have gone for the BMV 700 without Bluetooth instead. Overall I'm happy and confident it's accurate and this seems to still have been the best option for me.





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[MattBW]

Power draw for this is tiny at about 2 mA about 1.5Ahr a month


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[MattBW]

Does also work with Apple Watch I should have mentioned


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[Erbster]

I wonder how it would have to be attached on an Ocean (two batteries in parallel ). Is there any guidance in the instructions?

Btw, I have a number of NASA instruments on my boat. Good value, great product support and UK made.


Charles

 

[MattBW]

The instructions say it can be fitted to a battery bank but I'm not sure you would get any extra functionality over the Cali panel.

Certainly is good value and very interesting and useful info for me.


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[Stoneybroke]

Thanks for this @MattBW
I was looking at one of these, but used a data logger from Maplin plugged into a lighter socket to see what was happening.
Having monitored the battery use and charging over a few long weekends either without any hook-up or with solar (some wet weekends too) decided that, for our purposes, the extra gizmo wasn't necessary at the moment, but that might change. I will watch your updates with interest.

 

[MattBW]

That looks interesting, is there anyway to read the live voltage from it or does it need to be via a pc?

Before this setup I tried a few plug in units (all chinese), each one has been inaccurate. When you accounted for the potential voltage drop in the cables they could be even worse.

The square one was the best at only 0.2v out. I also have a white one with 2 usb ports and that was 0.3v out.

The one with the temp gauge was 0.5v out last time I used it. That is so inaccurate as to be a bit useless. Enough to potentially damage your battery if you are using it to judge when to stop use (unless you are aware).

The NASA is thankfully accurate to 0.01 and matches my multimeter I'm glad to report..

 

[MattBW]

I wonder how it would have to be attached on an Ocean (two batteries in parallel ). Is there any guidance in the instructions?

Btw, I have a number of NASA instruments on my boat. Good value, great product support and UK made.


Charles

@Erbster
Q My battery is made up of a bank of several batteries. Is that a problem? A Not as long as the combination produces a nominal 12 volts, and all the current drawn from the bank passes through the shunt.
http://www.nasamarine.com/wp-content/uploads/2016/06/BM1-Bluetooth.pdf

 

[Stoneybroke]

That looks interesting, is there anyway to read the live voltage from it or does it need to be via a pc?

Before this setup I tried a few plug in units (all chinese), each one has been inaccurate. When you accounted for the potential voltage drop in the cables they could be even worse.

The square one was the best at only 0.2v out. I also have a white one with 2 usb ports and that was 0.3v out.

The one with the temp gauge was 0.5v out last time I used it. That is so inaccurate as to be a bit useless. Enough to potentially damage your battery if you are using it to judge when to stop use (unless you are aware).

The NASA is thankfully accurate to 0.01 and matches my multimeter I'm glad to report..

View attachment 24460

Not live data. Plug in to laptop and examine the graph. Mrs S was away on her own at her Dog Agility weekends, so that worked for us.
I did put a new solar controller on the fold out 120w panel we have - gone from flashing lights to readouts of battery, panels, plus draw of using the direct feed from the controller, so she could be reassured solar was working and battery ok.

 

[MattBW]

The time remaining counter is useful for constant loads, of course the fridge and heater aren't constant. However it does give a good indication of power use and reflects in the overall charge percentage. Useful. The calculation for time remaining seems to fluctuate quite a lot which doesn't give me confidence in it. E.g. 89hours at 6amps clearly isn't right or the 35h at 4.7a. I may have just caught as it was updating however it eventually settled at 16hours.

Here the fridge has been turned on from warm and the max draw of amps is 6. However once cold it uses less and is barely on.

The app requires you to connect and if you stay within the van or very nearby it remains connected.

This will allow you to use the apple watch to check the details without looking at your phone. This isn't a live feed but updates every 3 seconds or so.

Unfortunately if you leave the van or go a few meters away the phone will lose the connection and it doesnt seem able to automatically reconnect. I'll play with this later if to be sure but at present returning requires a manual reconnection. As I don't need to look at it constantly it's not too much of a problem.


Lastly battery usage, by that I mean phone battery for the app. It seems high up the list for not a lot of usage so closing the app when not in use may save phone power.



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[MattBW]

Apps been updated but can’t see much difference to be honest. Now has a monitor mode and slightly nicer looking:

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[MattBW]

I should say its now connected to my starter battery too, so I get read outs for both batteries. You only get volts for the engine battery but that is enough.

 

[KGCali]

Hi All, here is another alternative that provides Bluetooth battery monitoring and can be bought from eBay for around £16 or Amazon for £20-30.
BLE (BM2) BATTERY MONITOR
Manufactures website and manual...

Battery monitor - AQ-TRON

Features Android 4.3+, iPhone 4S+, iPad3+ Alert user if charge is low Review charge history in graph mode Show the state of charge of battery in real time Check starting and charging systems All 12V car battery Specifications Shows voltage information when user is close to the vehicle, no need...

aqtron.com