Nasa clipper bm-1

[southace]

I have just fitted the battery monitor instrument....was happy with the instalation instructions just remember to put your battery charger neg onto the neg of the shunt not dirrect to the battery or you will not be able to read the amps charge. Im not sure why it only showed 18.5 amps when my battery charger was on 21 amp setting perhaps the charger is just a approx.
The only down side of the unit I found is that the light goes out after 1 minute so u have to find it in the dark to check your load each time....and the little shadows in the corners of the dispay apparentlly to highlight areas of intrest....I really think that does nothing but ruin the appearence of the unit... other than that Im happy to have the unit aboard.

[skipmac]

Hi Southace,

Could be several reasons why the charger is set on 21A but the monitor only shows 18.5.

First, depending on how the monitor and batteries are wired, some of the output from the charger will be feeding lights, pumps or any other loads switched on inside the boat. So if the charger is really putting out 21A, then you could be putting 18.5 in the batteries and running the lights with 2.5A.

Another possibility, no matter what the capacity of the charger, if your batteries are charged then the charger will not be putting very many amps into the battery.

And, as you say, the meter on the charger could be approximate.


Skip

[southace]

Originally Posted by skipmac

Hi Southace,


Could be several reasons why the charger is set on 21A but the monitor only shows 18.5.

First, depending on how the monitor and batteries are wired, some of the output from the charger will be feeding lights, pumps or any other loads switched on inside the boat. So if the charger is really putting out 21A, then you could be putting 18.5 in the batteries and running the lights with 2.5A.

Another possibility, no matter what the capacity of the charger, if your batteries are charged then the charger will not be putting very many amps into the battery.

And, as you say, the meter on the charger could be approximate.


Skip

Thanks for the comment mate, yes I tried that shut all my power down and sat in the dark last night still no change.... Im going to hard wire charger to the shunt as its hard to get a good fix with the clamps...could see a volt drop with multi meter from clamps to shunt.

[skipmac]

Originally Posted by southace

Thanks for the comment mate, yes I tried that shut all my power down and sat in the dark last night still no change....

Ok, now that's funny. Did the same thing myself when I installed my monitor. Have thought about wiring options and have not thought of a simple way to set up the charger and monitor so you can see the full output of the charger when it is also feeding power to the boat and have the monitor work correctly otherwise.

[southace]

Originally Posted by skipmac

Ok, now that's funny. Did the same thing myself when I installed my monitor. Have thought about wiring options and have not thought of a simple way to set up the charger and monitor so you can see the full output of the charger when it is also feeding power to the boat and have the monitor work correctly otherwise.

Do you have the same monitor skipmac if so do you understand Amprere hours total?? This chapter is well confusing! I think they show the total net of amps per charge or dishcarge but Im not sure if it is working out right?

[skipmac]

I have a Victron BMV-602. Not familiar with the Nasa clipper but will google it and see if I can learn anything.

Skip

[skipmac]

Found the manual online and will try to check it out this evening. I would think your monitor would work about the same as most.

In my system I have 2 batteries of +/- 180 amp hour capacity each connected in parallel. So to set up the battery monitor I have to enter the total amp hour capacity of the batteries, so 360 amp hours. Then the monitor measures amps in and out to tell me how much I have in the batteries. If 75% charged then in theory I would have 270 amp hours available.

If you are asking about the meaning of amp hours, that is how many total amps the batteries can supply at a certain rate. So if you have a 200 amp hour battery then from full charge it will theoretically give 2 amps for 100 hours until the batteries are dead. This is not true in the real world of course as the batteries will give you fewer total amps if you have a big load and more if you have a really small load and you never want to run the batteries past max 50-60%.

[bgallinger]

I bought a Clipper BM-1 also thinking it was a very clever way to track amp loads.
1) The handy drawing they supply does not include the 4 way switch most of us have...Battery 1, Battery 2, BOTH or OFF.
2) I have 96 Ah batteries for domestic use and 1 75 Ah for engine. I have just learned that the BM-1 is not for loads in excess of 100Ah aklthough its easy to set the meter up for 200 Ah.
3) My BM-1 did not show amp loads when I wired it as instructed. The meter stubbornly showed 0 Ah until I wired the negative directly on to the battery post (-).

Any ideas? I wrote Nasa, but they were not much help!