Battery monitors: BM-1 vs Trimetric 2030 vs ?

[Mwilliamshs]

The NASA Clipper Battery BM-1 is about $200 and comes with 100 AMP shunt and a cable assembly. There is also a BM-2 available for ~$240 with a 200A shunt.

Specifications:
Supply voltage: 8-16 volts DC
Supply current: 3 milliamps
Battery capacities: 5-650 AMP Hour
Max Charge Current: 100 Amps Max
Shunt: Standard 50 millivolt @ 100 Amp
Cables Supplied:100 Amp shunt link to M8 Ring terminal. 5 metre from display unit to battery - fused and fitted with ring terminals for shunt, fuse holder, and M8 ring terminal to battery.
Display Unit: Standard 110m squre clipper case. High contrast LCD, backlit for night viewing.

The Bogart Engineering Trimetric 2030 is about $150 and does not come with a shunt. 100 and 500 amp shunts are available. The Trimetric 2030 is available at least one place with cables and 100A shunt for $207.

Specifications:
Supply voltage: From 10.0 – 65.0 volts for main battery. From 0.0 to 100 volts on secondary battery
Supply current: 32mA with display lighted. 16 mA with display off.
Battery capacities: 10 to 10,000 AMP Hour
Max Charge Current: 300 Amps, with 100A/100mV shunt
Cables Supplied:
Unit TM-2030-A: 4-1/2 x 4-3/4 panel with circuit board 1-1/8 (max) in. deep. (11.4 x 12.1 x 2.85 cm.)

I've gotten lots of feedback on the TM2030 and only a little on the BM-1. Anybody here got experience with one or both?
Can anybody recommend another monitor they have experience with in this same price range (~$200 total)?

 

[Mwilliamshs]

The Victron BMV-700 is about $170 and includes a 500A shunt.

Specifications:
Supply voltage: 6.5-95 DC
Supply current: <4ma (backlight off)
Battery capacities: 20-9999 AMP Hour
Max Charge Current: 500 Amps max (had to look into the manual for this number, it's not on the data sheet) (called Input Current Range)
Cables Supplied: 10 meter 6 core UTP with RJ12 connectors and cable with fuse for &#8216;+' connection
Shunt: Standard 50 millivolt @ 100 Amp
Display Unit: 2.0 inch diameter, 1.2 inch depth

 

[Mwilliamshs]

I like the BM-1's big screen and the reviews I've seen of it make it seem very easy to use both for programming and accessing different data. I like that it displays multiple things at a time unlike scrolling through the TriMetric. I'd like to see more of its backside and how the connections are made. Looks like maybe its cable is attached to the monitor already and connections are made via a terminal block to an extension cable or directly if within 5 meters. I think. Maybe. I ESPECIALLY like the time to charge and time to discharge displays I saw in a youtube video of a campervan from Chile and in this .pdf from Sailing Today.

I like the TriMetric's rock steady reputation and Bogart's reputation in general. I wish it could display things in a less cryptic way.

I don't really like anything about the Victron that I know of. I'm sure its size and dash-mountability are a plus for some folks, but not me.

 

[Mwilliamshs]

Here's a no-name Chicom battery monitor from eBay.

Costs ~$42 with free shipping and includes a 500A shunt.

Specifications:
Supply voltage: 5-40 volts DC
Supply current: not listed
Battery capacities: .1-9999AH
Max Charge Current: 500 Amps Max (determined by shunt)
Shunt: Standard 500 Amp
Cables Supplied: 7 pin
Display Unit: 4 digit red LCD, 79mm x 43mm 30mm

I'll look for reviews.

Here's a shot of one from a youtube vid, looks pretty much the same unit to me.

Cheaper here and they've sold about 200 more. Here's the manual in pdf.

Reviews:

1) Well i decided to get one and it arrived in a couple of weeks. What i would say is that you need to calibrate it so if you are looking for something to work straight out the box then don't buy. Volts wise it seems good, Amps it needs a little bit of messing about with to get an accurate reading. The other features like the AH counter works on you telling it the capacity of your battery and then simply counts them out and back in. It doesn't appear to have any intelligence in it for that. Mine also tends to bounce around a little when it has no load on it, not been able to sort that out just yet...So is it worth it? For me it was, i had nothing to start with and now have something. If i find i need much more accuracy then i might invest in something better but this may just do the trick for me.

This forum has lots of support for this meter, including some re-written and expanded instructions here

2)Great meter, easy to calibrate and set alarms, top of the line construction.

3) Here is one of the original meters in this thread being used for charge monitoring. It works well but seems to read a bit high in current as the shunt heats up (indicating the shunt material is not optimal). The power supplies regulate at 12 amps but after a short time will display 12.5 amps. This also going to affect the integrated amp-hours, making them read a bit high.

4) (same thread as #3) They got about 99.8% good rates. With over 10k sold. So I guess risk is quite low to receive all bad ones. And as I said if seen a lot China crap. This is one of the nicest products I've seen.

5) (from the youtube video where I got the the picture) Yeah I really enjoy having it. I couldn't quite justify a more expensive trimetric but figured I'd take a risk with this and I've been more than happy. I like how the front of Maycee is custom with the wall and couch setup.&#65279;

also from #5

I agree that it doesn't do everything that a trimetric does but this ebay unit keeps track of charging amps that go in and amps that are used and gives you a battery percentage and amp hours left in your battery bank as well.&#65279;

6)shows he has one installed. I'll look for his review of it

View attachment 323737

 

[perkj]

Check out the Victron 702, it a nicer unit than the 700. Has the ability to do one of the following:

1. measure starter voltage
2. measure mid-voltage (and give a warning if the battery string is getting out of balance)
3. measure the battery temperature

&#8230;700 doesn't have the option for any.

 

[Mwilliamshs]

Check out the Victron 702, it a nicer unit than the 700. Has the ability to do one of the following:

1. measure starter voltage
2. measure mid-voltage (and give a warning if the battery string is getting out of balance)
3. measure the battery temperature

&#8230;700 doesn't have the option for any.

1) what's starter voltage? The voltage required to start my engine? If so, why would I need to know that?
2) what's mid-voltage? The voltage between multiple batteries? If so I'll have a monitor (Trimetric, etc) on my house bank and the OE gauge on the start battery. The use of a hydrometer will let me know if house batteries are out of balance (specific gravity of each cell measure) and regularly scheduled equalization is an option on most all solar chargers on my list (see other thread).
3) temperature compensation is likewise a feature I require of my solar charger but I guess reading their temperature separately could be interesting. An infrared thermal gun is a permanent resident in my toolbox and I enjoy measuring lots of things with it. I'm sure batteries will make that list.

 

[perkj]

1) what's starter voltage? The voltage required to start my engine? If so, why would I need to know that?
2) what's mid-voltage? The voltage between multiple batteries? If so I'll have a monitor (Trimetric, etc) on my house bank and the OE gauge on the start battery. The use of a hydrometer will let me know if house batteries are out of balance (specific gravity of each cell measure) and regularly scheduled equalization is an option on most all solar chargers on my list (see other thread).
3) temperature compensation is likewise a feature I require of my solar charger but I guess reading their temperature separately could be interesting. An infrared thermal gun is a permanent resident in my toolbox and I enjoy measuring lots of things with it. I'm sure batteries will make that list.

Starter voltage is that is displays the actual voltage of the starter battery. I not actually sure what midrange voltage is.

 

[fiddypal]

Can someone explain the purpose of the shunt and different shunt values?

Thanks!

 

[Mwilliamshs]

Can someone explain the purpose of the shunt and different shunt values? Thanks!

An ammeter is what reads current and is needed to calculate things like how much power you've used, how much is remaining, etc. To do this it must either a) be inline with the load or b) use a shunt.

a) requires that all your current flow directly through the ammeter so not only requires quite a robust gauge and heavy cabling but also causes a considerable loss of power as it passes through the gauge then onto the load

b) is the much more practical solution. A shunt is a very precise, very low impedance resistor. By measuring the load passing through this known resistance the ammeter can infer the load without causing a large loss in power or needing to have all the power pass through the meter itself.

Imagine not that we're discussing digital gauges but think back to the old days where an ammeter was mounted in the dash of your car. A real heavy cable would need to come from the generator through the firewall under the dash through the gauge then back through the firewall and to the battery. This was not only expensive and cumbersome but fairly dangerous. Shunts solved that problem since they can use small, cheap, flexible wire to connect a dash mounted gauge to the car's main power circuit without passing high current all over the place.

A shunt's rating is how much power can pass through it. A 500 amp shunt can be used in a system with 5 times the current of one where you'd use a 100 amp shunt.

For more in depth explanations you can look here and here

From Bogart:


-100A/100mV SH-100-100 Maximum recommended continuous current: 70 Amps. Meter current resolution is 0.01 amp. Size: 2 x 1-3/16 x 1-3/4 in.; 4.8 x 3 x 4.3 cm.

- 500A/50 mV SH-500-50; Maximum recommended continuous current: 410 Amps. Meter current resolution is 0.1 amp. Size: 3-1/4 x 1-3/4 x 1-7/8 in.; 8.25 x 4.5 x 4.75 cm.

- 1000A/100mV SH-1000-100 Maximum recommended continuous current 650 Amps. Meter current resolution is 0.1 amp. Size: 7-3/4 x 2-1/2 x 1-1/8 in.; 19.7 x 6.3 x 2.8 cm.

More info:
http://bogartengineering.com/sites/default/files/docs/SHUNTInfo2.pdf

 

[fiddypal]

Makes perfect sense, thanks for the write up!

 

[Mwilliamshs]

The Merlin SmartGauge is a highly regarded battery monitor in the boating world. It uses no shunt and has only 3 wires to connect. THIS UNIT IS NOT DISTRIBUTED IN THE US. SEE BELOW

Specification:
Supply Voltage Range: 8-40V DC.
Supply Current (Sleep Mode): 5mA.
Supply Current (Display On): <15mA.
Operating Temperature Range: -25 To +85C.
Accuracy For State Of Charge (Charge): +/- 10%.
Accuracy For State Of Charge (Discharge): +/- 5%.
Accuracy Voltage: +/- 0.5V DC.
Dimensions (Front Panel): 110 x 76mm.
Dimensions (Body): 95 x 64mm.
Total Depth: 28mm.
Weight: 0.2Kg.
Protection Rating: IP20 (Front Panel IP65).
Standards: CE, ISO7637-2.

There is a similar appearing unit, the Balmar SmartGauge, that is the same thing just dressed for the US market.

Makes sense that Merlin and Balmar SmartGauge units look similar considering:
"...The SmartGauge Electronics website is an interesting place to visit but I'm not sure much has happened there since Merlin Power Systems acquired Smartgauge in 2009...note that Balmar now distributes Smartgauge in the U.S. (reportedly with excellent technical support).
See more at http://www.panbo.com/archives/2014/...aims_paradigm_shift.html#sthash.msbY5cDI.dpuf

Goes for ~$320 at West Marine.

 

[Pinnacle Campers]

Here's a no-name Chicom battery monitor from eBay.

Costs ~$42 with free shipping and includes a 500A shunt.

Specifications:
Supply voltage: 5-40 volts DC
Supply current: not listed
Battery capacities: .1-9999AH
Max Charge Current: 500 Amps Max (determined by shunt)
Shunt: Standard 500 Amp
Cables Supplied: 7 pin
Display Unit: 4 digit red LCD, 79mm x 43mm 30mm

I'll look for reviews.

Here's a shot of one from a youtube vid, looks pretty much the same unit to me.

Cheaper here and they've sold about 200 more. Here's the manual in pdf.

Reviews:

1) Well i decided to get one and it arrived in a couple of weeks. What i would say is that you need to calibrate it so if you are looking for something to work straight out the box then don't buy. Volts wise it seems good, Amps it needs a little bit of messing about with to get an accurate reading. The other features like the AH counter works on you telling it the capacity of your battery and then simply counts them out and back in. It doesn't appear to have any intelligence in it for that. Mine also tends to bounce around a little when it has no load on it, not been able to sort that out just yet...So is it worth it? For me it was, i had nothing to start with and now have something. If i find i need much more accuracy then i might invest in something better but this may just do the trick for me.

This forum has lots of support for this meter, including some re-written and expanded instructions here

2)Great meter, easy to calibrate and set alarms, top of the line construction.

3) Here is one of the original meters in this thread being used for charge monitoring. It works well but seems to read a bit high in current as the shunt heats up (indicating the shunt material is not optimal). The power supplies regulate at 12 amps but after a short time will display 12.5 amps. This also going to affect the integrated amp-hours, making them read a bit high.

4) (same thread as #3) They got about 99.8% good rates. With over 10k sold. So I guess risk is quite low to receive all bad ones. And as I said if seen a lot China crap. This is one of the nicest products I've seen.

5) (from the youtube video where I got the the picture) Yeah I really enjoy having it. I couldn't quite justify a more expensive trimetric but figured I'd take a risk with this and I've been more than happy. I like how the front of Maycee is custom with the wall and couch setup.&#65279;

also from #5

I agree that it doesn't do everything that a trimetric does but this ebay unit keeps track of charging amps that go in and amps that are used and gives you a battery percentage and amp hours left in your battery bank as well.&#65279;

6)shows he has one installed. I'll look for his review of it

Has anyone used one of these on here? It's like $36 shipped, seems like an economical way to monitor batteries? What's the downside? Lack of Marine cred? Promoting Chinese goods?

 

[jonyjoe101]

Its what I used, I had it for about 3 years running 24/7 365 days , its always connected to the battery so I can see the battery status at night. Power use is insignificant. From my use they are reliable.

It might be off be off by half a amp when compared with what my ecoworthy controller LCD display shows, but that one is also off when compared to a accurate multimeter, but its closed enough to see how much amps your battery are getting. If I need more accuracy I use a dc wattmeter, which are very accurate and can handle up to 60 amps.

The main feature of this meter is its large LED which you can read from a distance even in daylight. LCD meters even the lighted ones you need to get up close to read them. These also dont need a shunt but are limited to a max of 30 amps, but only need 2 wires from charge controller and 2 wires to battery.

I only payed 20 dollars for mine on ebay shipping included. Its all you need to monitor your battery. If your lead acid battery reads 12.7 volts its full, if it reads 12.1 its at 50 percent. While charging, it will read what the controller is putting out, when it gets up to 14 volts its almost full. This is a cheap way to monitor if your controller is working and putting any amps into your battery.



this is the dc wattmeter I use to measure actual amps use by dc equipment. (cost 12 dollars) Its all you need for that purpose. You can also use this instead of the LED combo meter above, but LCD screen is too small to be convenient but it does the same thing.

 

[Pinnacle Campers]

Thanks for your input.
Are you able to monitor your engine alternator amps coming in?

 

[DiploStrat]

Couple of random comments:

-- Properly installed, a shunt based battery monitor will show you net amps in and out of the battery, regardless of source. So if, for example, your solar controller shows amps out, your battery monitor will show how many are going to the battery, and the difference will be the number of amps used by loads.

-- While it is INTERESTING for you to know the state of charge of your batteries, it is ESSENTIAL that your charging devices know the state of charge and that they respond immediately and correctly. (For lead acid, lithium are said to be more tolerant.)

The old saw, "I need a battery monitor/voltmeter to know when to charge my batteries" is dangerous. You need to recharge a lead acid battery as soon as it is discharged and you never want to leave it sitting discharged.