Clipper BM-1 Battery Monitor

Wanderman · May 2011

I have been looking at all the battery monitors out there to replace (maybe) my old Ample Power Systems Energy Monitor Model #2020

I already have a 400amp shunt in place (50mV) and was wondering if the Clipper BM-1 would be able to use it to give me accurate readings above it's "limit" over 100amps if I connected it to my existing 400amp shunt.

It is supplied with a 100AMP (50mV) shunt. So looks to limited to 100 amps in/out

Here is a link:

http://www.clippermarineusa.com/product.php?id=37341

Thanks,

Rick

westbranch · May 2011

Re: Clipper BM-1 Battery Monitor

have you Looked at the Xantrex Link 10, goes to 2000 Ah.

e

petertearai · May 2011

Re: Clipper BM-1 Battery Monitor

The display on that looks fantastic. I got a victron one and it included the shunt,simple to install. But the one you have put a link to sure has a very clear looking display.

waynefromnscanada · May 2011

Re: Clipper BM-1 Battery Monitor

Definitely the very best display I've seen, I LOVE it! Have been looking for a monitor worth buying for some time, but most are unnecessairly complicated to use, only displaying one thing at a time, and have to keep punching buttons to get the whole picture bit by bit. This one gives the whole picture at one glance. Perfect. One concern though - - states 5 M from battery. I need to go 115 feet, otherwise it's no good to me. Anyone know if it can be extended and still operate?
Ran into unexpected distance limitations with the remote on/off/display for the Xantrex Pure Sine 1800/12. Tried different cables, even Cat-5, but no go after 50 feet. However the remote meter for the Morningstar CC has no problems with 115 feet.

System2 · June 2011

Re: Clipper BM-1 Battery Monitor

I use two of the BM-1 monitors (one in a caravan , the other in a transit van) and can confirm that they work well . The state of charge % graph is best ignored when under heavy load though, but sorts itself out when back at rest or light load.

They do seem to be very accurate on the amps charging/discharging and will identify a load of 0.1 amps (an led bulb) being switched on and off.

The 50mv 100 amp shunt can get quite hot under heavy load , but mine has handled a 125 amp load and survived ok.

There has been a few discussions about them on the below uk boat forum , which you might find useful. (MODs feel free to remove link if against the rules)

http://www.ybw.com/forum

The meter only reads the voltage drop across the shunt , the load current does not pass through the meter.

From what I have read there it is possible to swap the shunt as the meter can cope with reading more than 100 amps (as above I have seen 125 on mine).

The important part is to keep the 50mv@100 amp rating the same i.e.
The following shunts should in theory work .

50mv 100 amp
100mv 200 amp
150mv 300 amp
200mv 400 amp

I still use the supplied shunt , but plan to get a 100mv 200amp shunt , which costs £50 over here in the UK , but you can probably get them much cheaper on your side of the pond!

The supplied cable between the meter and the shunt is joined at the back of the meter with a scotch block , so it could deffinately be extended. I am not sure what effect this would have on the meter readings though, but in theory if you used sufficently large enough cables then it should be ok.

Off topic

I have been reading through your RV thread where you mention using a solar collector , if weather permits I will installing one on my caravan (travel trailer in the USA) next week.
I have built one from an old fridge radiator that will heat water inside a small 6 litre calorifier (enough water for a shower) and have a 12 volt 250watt immersion on order that will be used to finish off the heating if required.
It will be plumbed in via 6 manual shutoff valves so that it can be used as
1) Standalone
2) The existing 9 litre water heater (LPG or 240V electric) can be used standalone
3) The solar heater can act as a pre heater for the water supply to the LPG Heater
4) Using a second pump the water can be circulated between the 2 heaters

Testing in the garden on a sunny April day (yes in the UK!!) the collector heated the 6 litres of water from 16 Deg C to 37 Deg C in under 2 hours , so it looks promising . Real world testing will prove how effective it is in various conditions.

waynefromnscanada · June 2011

Re: Clipper BM-1 Battery Monitor

Good info. Thank you shadyocuk.

Wanderman · June 2011

Re: Clipper BM-1 Battery Monitor

Hmmm... Can anyone give me a basic electrical theory primer as to why you would have to increase the mV range on the shunt???

Why not 50mV at 400amp?

Thanks,

Rick

Cariboocoot · June 2011

Re: Clipper BM-1 Battery Monitor

Wanderman wrote: »

Hmmm... Can anyone give me a basic electrical theory primer as to why you would have to increase the mV range on the shunt???

Why not 50mV at 400amp?

Thanks,

Rick

Perhaps this will explain it for you: http://www.deltecco.com/resources.htm

Or maybe it will give you a headache.

Short form: a shunt is a stable resistor. The monitor measures the Voltage difference between one side and the other, and from that extrapolates the amount of current flowing through the shunt. Change the operating range of the system and you need to change the shunt to handle the amount of current and give an accurate reading.

Wanderman · June 2011

Re: Clipper BM-1 Battery Monitor

CBC,
OK I get the concept (I think) but the way I perceive it is the instrument reads from 0-50mV. That will be from 0-100% if we are talking about an analog gauge. If I want to increase the amount of current (AMPS) than the 0-100% deflection will still require 0-50mV.

Confusing...YES!

If the instrument wants to see voltages across the shunt of 0-50mV and then I send it 0-100mV (or 200mV even) wouldn't that be outside it's range?

I'm learning...I promise!

Rick

Cariboocoot · June 2011

Re: Clipper BM-1 Battery Monitor

The Voltage difference is the difference from one side of the shunt to the other in respects to B+.
The greater the difference, the more current is flowing. Up to the maximum the shunt is designed to handle.
So a 50 mV difference on the 500 Amp shunt means 500 Amps is flowing through it. The battery monitor uses this information, going in both directions, to calculate how much capacity has gone out/in of the battery.

Is that clearer, or am I building another forum tar pit here into which newbies sink and are never seen or heard from again?

Wanderman · June 2011

Re: Clipper BM-1 Battery Monitor

CBC,
Nope, I love learning new concepts.

Though, it does seem that the weak link here is the instrument NOT the shunt. The instrument (which swings from 0-50mV) needs to know that that represents 400A at full deflection not 100A with the supplied shunt.

Rick

Cariboocoot · June 2011

Re: Clipper BM-1 Battery Monitor

Rick;

Indeed you are right: any given meter is designed to work with a particular shunt or shunts. You may notice the higher Voltage differential on the smaller Amperage shunt: it's just like shifting scales on your DVM. You sacrifice a bit of accuracy for greater Voltage/Amperage measuring.

Some of the battery monitors "learn as they go", others don't. How well yours would work with the "wrong" shunt is guess work. Could be off by 20%. Might be able to adjust it somehow so the reading is correct or compensate for it. I can explain the basic principles (I hope) but when it comes down to a specific application ... Contact the manufacturer.

Wanderman · June 2011

Re: Clipper BM-1 Battery Monitor

CBC,
OK I will send them an email. I do not actually OWN one of these, but it seems like it has a few more convenience features overmy existing Ample Power Systems Energy Monitor #2020 AND will fit the existing cutout and wiring.

Worth an email at least...

Thanks,

Rick

BB. · June 2011

Re: Clipper BM-1 Battery Monitor

Remember that resistors are rated by maximum power dissipation.

So, the various ways to calculate power:

Power = Voltage * Current = V * I
P = V^2 / R
P = I^2 * R

With the resistors, their maximum power rating can be listed several ways--but in this case, it is:

100AMP * 50mV = 100 A * 0.05 V = 5 Watt dissipation
400amp * 50mV = 400 A * 0.05 V = 20 Watt dissipation

So, the second resistor is a larger rated resistor... But it will not work with the Battery Monitor unless the monitor has a "scaling" factor that can be changed in the meter...

I.e., the meter is setup to read 100 amps @ 0.05 volts full scale.

The second resistor would cause the meter to read 100 amps when 400 amps is flowing through it (at 0.05 volts full scale). So--using the second resistor on a "stock" meter setup would only display 1/4 the current actually flowing through the "larger" shunt.

-Bill

Wanderman · June 2011

Re: Clipper BM-1 Battery Monitor

BB...didn't I say that?

So it appears that i have to find a 200mV 400A shunt someplace.

Any ideas?

I did email Nasa Marine and ask them about changing the instruments internal calculation values so I can use the 50mV 400A shunt I already have, but I would guess the answer will be no.

Here is a photo of the existing shunt:

Some of the wiring here has already changed.

Maybe I can find the same brand or one that is close in size so i can use the same space without too much modification.

Rick

Cariboocoot · June 2011

Re: Clipper BM-1 Battery Monitor

This may be stating the bleeding obvious or possibly yet another example of my increasing number of senior moments but ...

If a company sells a battery monitor that requires a 200 mV 400 Amp shunt, shouldn't they be able to supply it? In other words: what does the manufacturer recommend? Sorry if that's redundant.

Wanderman · June 2011

Re: Clipper BM-1 Battery Monitor

CBC,
They say that short term memory is the second thing to go...I can't remember the first...

The company supplies a 50mV 100A shunt with the meter. 100A is just not enough for my application (including a healthy safety margin. I would likely be able to get away with a 200A shunt assuming the 1800W inverter was going full blast and all the other loads were switched on. Of course my battery bank would be toast after a few minutes of that so it's really a moot point.

Rick

mike95490 · June 2011

Re: Clipper BM-1 Battery Monitor

What gauge wire do you have feeding that shunt ? Looks like 14 ga romex to me. Say it isn't so.

Wanderman · June 2011

Re: Clipper BM-1 Battery Monitor

The shunt is fed with 2/0 from the battery and various sizes sized for various loads.

Rick

mike95490 · June 2011

Re: Clipper BM-1 Battery Monitor

Wanderman wrote: »

The shunt is fed with 2/0 from the battery and various sizes sized for various loads.

Rick

Unless the shunt wires are concealed somewhere, they look like they are coming out of that romex. I'd expect to 2 FAT wires, like going to the battery switches.

Cariboocoot · June 2011

Re: Clipper BM-1 Battery Monitor

Mike; the shunt wires are the black ones going to the right, exiting through a hole in the back along with the Romex and a small pair for he meter (looks like thermostat cable). I had to use the big screen to see it.

But you're right: they do not look like 2/0, which is about 1/2" in diameter with the insulation. Hard to judge from a pic, though. We'll have to take his word for it. Hopefully he knows what he's got.

Wanderman · June 2011

Re: Clipper BM-1 Battery Monitor

Mike,
You need to look closer at the photo. Take a look at the ring terminals you can clearly see 2/0 cable running to the through-hole to the battery. The romex is the shielded wiring to the meters. BTW: it isn't really romex it multi-conductor boat wire from ancor.

Rick

mike95490 · June 2011

Re: Clipper BM-1 Battery Monitor

OK OK. I just could not see the fine detail you folks can see, I just see a black blob, and did not realize the big wires went through the bulkhead.

Wanderman · February 2012

Re: Clipper BM-1 Battery Monitor

OK New Info!

Clipper/Nasa Marine has just introduced a 200 AMP version of their BM-1 100 Amp battery monitor called, oddly enough the BM-2!

I am thinking about installing one of these. It comes with a 50mV @200AMP shunt.

I still have the original Emon #2020 50mV @400AMP one. I am wondering if I could simply swap it out. The largest load I have is from the inverter (Xantrex XM1800) it's MSW and at max load could draw around 187Amps. (possibly more at surge) All the other loads (lighting, water pump, parasitic, etc.) do not amount to much.

What to you all think?

Opinions?

Rich

BB. · February 2012

Re: Clipper BM-1 Battery Monitor

Smaller shunt will be more accurate (2x as accurate as the larger shunt for smaller loads). However, it will waste a bit more power:

0.050 volts * 200 amps = 10 watts at 200 amps

The 50mV 400 amp shunt:

0.025 volts * 200 amps = 5 watts at 200 amps (the larger shunt has 1/2 the resistance as the smaller shunt).

Of course, if you have high surge current, you are getting voltage drop across the shunt--So, if you, for example, had a 400 amp surge (starting a pump), you would get 0.1 volt drop across the smaller shunt... Significant, but probably not a big issue for even a 12 volt system.

-Bill

westbranch · February 2012

Re: Clipper BM-1 Battery Monitor

Whoa, it costs 20 Pounds (~$32) more for half the max load current and half the max charge current capacity???

BB. · February 2012

Re: Clipper BM-1 Battery Monitor

Kind of answers that question... 2x difference in accuracy is not worth that much money. But it may pay to shop around a little (plus shipping and handling--that can always add a few bucks).

Deltec 500 amp, 50 millivolt current shunt
Price: $27.00

-Bill

Wanderman · February 2012

Re: Clipper BM-1 Battery Monitor

OK...I thought I had to get rid of my 50mV @ 400 Amp shunt and replace it with their 50mV @ 200 Amp one to work properly with the device.

Am I off base here???

Rich

BB. · February 2012

Re: Clipper BM-1 Battery Monitor

It depends, does your battery monitor have a configuration setting for the shunt? Many do...

-Bill

Wanderman · February 2012

Re: Clipper BM-1 Battery Monitor

Bill,
I am trying to replace my existing "Energy Monitor" with the BM-2 The existing one came with a 50mV @ 400 AMP shunt. I would like to replace the "head unit" with the Clipper BM-2, however it comes with a 50mV @200 AMP shunt. I am reasonably sure I can use the 200AMP shunt for my total loads, but was wondering (based upon posts) If I could NOT replace it and use my existing one. I do not believe so...but I could be wrong.

Rich

BB. · February 2012

Re: Clipper BM-1 Battery Monitor

I don't know--I went to the NASA/Clipper website and only found the BM-1 manual, and the last two pages (configuration settings) had a PDF error and did not load.

Unless the BM-2 can have the shunt value adjusted--You will need to get the correct shunt value or the meter will not be accurate.

Note that sometimes, you will find Shunts with different values...

200 Amps @ 50 mV is the same as 400 Amps @ 100 mV

In theory, if you could find somebody that can "calibrate" your shunt, they may take the old shunt and "adjust" it to the higher resitance required for the new meter.

By the way, the BM-1 says it comes with a "Standard 50 millivolt @ 100 AMP" shunt... Not the 400 Amp @ 50mV unit you said earlier...

Either you have a different shunt or the BM-1 meter (at least) is programmable...

-Bill

Clipper BM-1 Battery Monitor

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