nasa battery monitor

pcatterall said:
So... the score to date seems to be;-
5 members who have used them and like them
1 who is sort of neutral but has not used one
1 more who had one but changed due to 100ah shunt

2 who have not used them but think they are no use.

the OP who will have to make his mind up on the evidence provided!!
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The usual pattern of threads on Nasa kit is that a few people will realistically say "don't touch it with a bargepole", and a lot of others will say "I've got one and it's great... well it did break, but Nasa repaired it fairly cheaply".
 
NickRobinson said:
My boat has a BEP monitor, loads of features but I only ever use the volts. Too much faff to set/reset Amps/Ah.
I've bought some plug in v meters for just over a pound each. They can be moved around to check drops on cig lighter outlets. I've got them on boat and camper. https://www.ebay.co.uk/itm/LED-Display-12V-24V-DC-Digital-Car-Voltmeter-Voltage-Electric-Gauge-Volt-Meter/162780469853?epid=1256346822&hash=item25e678da5d:g:ED4AAOSwzRlaH0Nk
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That's just a volt meter. It doesn't do the same thing.

Try Merlin Powerguage Lite: https://www.ebay.co.uk/i/332203646317
 
PaulRainbow said:
The shunt looks like it came from a Jamboree bag, i would refuse to connect the engine battery negative to it. SOC is, as others have said, a joke best ignored. I would spend a little more and get a decent one, or not bother. The Victron BMV-700 is a good one.
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Seconded. We have the Victron and have absolutely no complaints. It works with NMEA2000 as well, so if you have a multi function instrument like a Raymarine i70, or a NMEA 2K chart plotter, you can display battery usage stats at the helm.
 
I’ve had a NASA BM2 since 2012. I added a Smartgauge a couple of years ago and, with hindsight, I have discovered that the NASA told me all I need to know, as the Smartgauge can be misleading if you aren’t aware of its shortcomings.

As already stated, the %age SOC is flakey, which was why I bought the Smartgauge, but that is equally flakey when it truly matters.
 
pvb said:
Have to agree, I certainly wouldn't consider buying a Nasa monitor. The Victron monitor is in a different league and isn't much more money.
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What does the Victron do that the NASA doesn’t? and how does it do things better?

Genuinely interested, as I am happy with my 5 year old NASA BM2, and am not sure what could be better, or added.
 
Can the BM-1 be adjusted to compensate for a 200A shunt? I'm assuming the 200A shunt has a lower resistance which would throw out the current measurement, or am I wrong about that? I'm about to fit a BM-1 on my boat and I was wondering whether I'd be able to start the engine using the house batteries with the standard 100A shunt (Volvo MD2010).
 
Had BM1 for ten years. Started with 660ah , now reduced to 440ah. Lead acid cheapo batteries.
It's a good idea to recalibrate every year or so (I estimate 5 to 10 percent reduction in battery capacity per annum).
Have always found it reliable.
Then again, I' m a cheapskate --- what do I know!
 
pvb said:
and a lot of others will say "I've got one and it's great... well it did break, but Nasa repaired it fairly cheaply".
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But not one person has said that about this product.

Seems difficult for you to accept the high level of user satisfaction (with a further 3 endorsements since you posted this) so you invent something to fit your prejudice.
 
Richard10002 said:
What does the Victron do that the NASA doesn’t? and how does it do things better?

Genuinely interested, as I am happy with my 5 year old NASA BM2, and am not sure what could be better, or added.
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Not used the NASA, but people have said they have issues with the percentage remaining. The one on the Victron is pretty accurate in my experience. Monitors current draw and charge fully on one battery and voltage on two (we have the shunt on our house battery for full monitoring but can also keep an eye on the engine battery voltage). With the optional accessory it also dumps battery status onto the NMEA 2000 bus so you can display battery details on your chart plotter or multi function instrument.

It's a very solid and functional piece of kit.
 
Elbows said:
Can the BM-1 be adjusted to compensate for a 200A shunt? I'm assuming the 200A shunt has a lower resistance which would throw out the current measurement, or am I wrong about that? I'm about to fit a BM-1 on my boat and I was wondering whether I'd be able to start the engine using the house batteries with the standard 100A shunt (Volvo MD2010).
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I asked this question to nasa about my bm1 100amp shunt, they said the shunt and cable is designed to take higher currents for a short period ie for very short burst to start my AD31 engine. I would only need to do this if the starter battery failed and had to use the link switch to start. Having said that, I would be cautious doing this and been meaning to get jump leads instead. I plan at some point to replace the 100amp to 200amp shunt, but wondered if I can do this with the bm1.
 
Elbows said:
Can the BM-1 be adjusted to compensate for a 200A shunt? I'm assuming the 200A shunt has a lower resistance which would throw out the current measurement, or am I wrong about that? I'm about to fit a BM-1 on my boat and I was wondering whether I'd be able to start the engine using the house batteries with the standard 100A shunt (Volvo MD2010).
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Scubadoo said:
I asked this question to nasa about my bm1 100amp shunt, they said the shunt and cable is designed to take higher currents for a short period ie for very short burst to start my AD31 engine. I would only need to do this if the starter battery failed and had to use the link switch to start. Having said that, I would be cautious doing this and been meaning to get jump leads instead. I plan at some point to replace the 100amp to 200amp shunt, but wondered if I can do this with the bm1.
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People have asked NASA about this in the past. IIRC they have been told it is Ok , although I dont think they have committed themselves to a maximum safe current for the shunt. The monitor will not of course display a reading over 100 but it apparently measures it and uses the correct figure in its calculations.

Your best bet will be to contact NASA. I believe they are always helpful

The BM1 has a 50mV at 100 amp shunt , The BM2 has a 50mV at 200 amps shunt which means that if you use the 200A shunt with a BM1 all your current measurements will be half what they should be.
 
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I installed my BM1 in April 2010 and I must say it's one of the most useful things I have added to the boat. As long as you remember to set it to zero (once you disconnect shore power) the accumulated amps in or out as well as voltage and amp in use are all absolutely accurate (the % is useless). Very accurate to measure the effect of my solar panel too. Although my understanding is that NASA instruments are not the best around (you get what you pay for I guess) I am very satisfied with this little bit of equipment.
 
Richard10002 said:
What does the Victron do that the NASA doesn’t? and how does it do things better?

Genuinely interested, as I am happy with my 5 year old NASA BM2, and am not sure what could be better, or added.
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I had a BM1 in the old boat and a Victron BMV 700 on the new. The Victron cost me less than a BMV 200.

The Victron measures up to 500A, calculates state of charge correctly taking account of Pukets effect and records much more information such as last discharge, deepest discharge and the number of times the battery goes below 65% capacity. Its also possible to log the data from the Victron.


However, the BMV also measures the voltage of the starter battery but a cheap vottmeter is all one needs for that.

It depends on your usage and requirements. For many a straight voltmeter may be sufficient.
 
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DuncanHall said:
I had a BM1 in the old boat and a Victron BMV 700 on the new. The Victron cost me less than a BMV 200.

The Victron measures up to 500A, calculates state of charge correctly taking account of Pukets effect and records much more information such as last discharge, deepest discharge and the number of times the battery goes below 65% capacity. Its also possible to log the data from the Victron.

It depends on your usage and requirements. For many a straight voltmeter may be sufficient.
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+1

you don't have to reset when out of shore power, or when you finish a long motoring trip that actually fully charges your batterie(s) with the Victron it just works.
Further, if you have solar, there's no way to do this resetting business, and it's really pointless.

I'm pretty sure if the ones using the NASA for some reason had the Victron, they wouldn't go back to the NASA.
Yes, I do have the BMV700 (and annoyed I didn't read the specs carefully and didn't go for the next model up)
I also have the bluetooth module but found it more interesting to plug it in the MPPT controller and get more accurate data of what the panels produce.

V.
 
vas said:
+1

you don't have to reset when out of shore power, or when you finish a long motoring trip that actually fully charges your batterie(s) with the Victron it just works.
Further, if you have solar, there's no way to do this resetting business, and it's really pointless.

I'm pretty sure if the ones using the NASA for some reason had the Victron, they wouldn't go back to the NASA.
Yes, I do have the BMV700 (and annoyed I didn't read the specs carefully and didn't go for the next model up)
I also have the bluetooth module but found it more interesting to plug it in the MPPT controller and get more accurate data of what the panels produce.

V.
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Vas you could load Victron's Venus software on a raspbery Pi and connect to both the MPPT and BMV for a holistic view. The cost is relatively small. If you can connect to WiFi (on board the Pi) this gives a full remote monitoring capability.
 
I fitted BM1's to two previous boats and a BM1 compact to a camper van. Its good to see an instant battery state, but on the last boat, I seemed constantly to be re-calibrating it. Probably a battery issue rather than the BM1.
On my new boat, I decided to fit a Smartgauge instead. There is no shunt, it connects direct to the battery bank, so no recalibrating. There is no constant display visible, just three buttons. 1. house battery voltage. 2. house battery percent remaining and 3. start battery voltage. What more could you need?
I also have a Victron unit for the solar panels. I access that via bluetooth to my phone.
 
I have had a BM1 on my Oceanlord since 2007. It works perfectly. I have started the engine on the house batteries (by mistake) many times and have had no issue with that.

I ignore the % charge as I dont think its accurate, preferring to use the standing voltage.

Its real value to me is that I know precisely what the alternator and sun panels are putting into the batteries, and what the appliances are taking out. So it is far more functional than a straight volt meter - which does not tell you enough about amps in and out.

The boat is in the Med and is very very rarely on mains for charging. I am more than happy with what it does.
 
I have just installed a new battery monitor called the Pico. Initial impressions are very positive. It is beautifully made from glass and anodised aluminium with a gorgeous display.

It it a very versatile monitor that will measure multiple batteries, temperatures, currents etc. It also has a very nice recording barograph. I suspect it will be overkill for the OP's requirements, but it may be worth considering for others reading the thread.

They do sell a no frills version, but it is still expensive at €219 and i think this model does not include a shunt. So in addition you will need one of their 300A or 500A shunts.


https://www.simarine.net/product/pico-one-battery-monitor/
 
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Chris_Robb said:
I have had a BM1 on my Oceanlord since 2007. It works perfectly. I have started the engine on the house batteries (by mistake) many times and have had no issue with that.

I ignore the % charge as I dont think its accurate, preferring to use the standing voltage.

Its real value to me is that I know precisely what the alternator and sun panels are putting into the batteries, and what the appliances are taking out. So it is far more functional than a straight volt meter - which does not tell you enough about amps in and out.

The boat is in the Med and is very very rarely on mains for charging. I am more than happy with what it does.
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exactly why i want one with Amps :)
 
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