zoidberg
Well-known member
What's to know about them? What's not to like...?
NASA BM-1
- Thread starter zoidberg
- Start date
Tranona
Well-known member
Simple and relatively cheap, but the capacity readings are imprecise. Best used for monitoring consumption and standing voltage. Had one on my last 2 boats and have one to fit the GH when I finish the rewiring.
Sandy
Well-known member
A nice simple volt and ammeter. They do have a % left calculation of power in the battery that is based on some formulae that worked for me on lead acid batteries. Having upgraded my switch panel I went for one with an integrated volt and ammeter.
SlowlyButSurely
Active member
One factor that persuaded me to buy a BM1 was the size of the display. I can read it without glasses from most parts of the boat.
cmedsailor
Well-known member
I had it on my previous boat. Large display so easy to read from a distance. Very good at counting amps in and out so you know your constant consumption and cumulative discharged (just remember to set it to zero!). I never used the percentage factor. Always preferred the cumulative amp figures.
doug748
Well-known member
The case design looks good compared with the alternatives, which is something not regularly said of NASA products. The BM1 will not measure large loads reliably, like engine starting (The BM2 will) but it does not matter a lot and they don't seem to take any harm.
The battery capacity bar graph is easily discouraged and tends to show the battery half exhausted after a few minutes, on the plus side it soon bucks up when a charge is applied. Best treated as an interesting novelty.
They seem to be very reliable, I think that most folk who have them, like them.
The battery capacity bar graph is easily discouraged and tends to show the battery half exhausted after a few minutes, on the plus side it soon bucks up when a charge is applied. Best treated as an interesting novelty.
They seem to be very reliable, I think that most folk who have them, like them.
zoidberg
Well-known member
It seems the BM-1 can monitor Start Battery voltage in addition to House/Service Battery, if an appropriate cable is connected as per the installation instructions.
It is unclear from the FAQs how in practice the two blocks of information are accessed. It's likely 'something simple', but HOW...?
It is unclear from the FAQs how in practice the two blocks of information are accessed. It's likely 'something simple', but HOW...?
Graham376
Well-known member
Have one and would buy another. Accurate volts and amps in/out but, as others have said, capacity remaining bar graph only a rough indication.
Ammonite
Well-known member
One button to toggle between the two displays. Just voltage for the start battery though.
