Victron BMV-700 Battery Monitor

[Ceirwan]

I recently installed one.

I seem to be getting some inconsistent current draw readings, its saying I'm drawing 0.7-0.3 amps, despite the main switches being off and nothing else connected, voltage is rock steady.

Everything is connected exactly as per installation diagram so I'm hoping its just a case of needing some time to steady out.

 

[pvb]

I recently installed one.

I seem to be getting some inconsistent current draw readings, its saying I'm drawing 0.7-0.3 amps, despite the main switches being off and nothing else connected, voltage is rock steady.

Everything is connected exactly as per installation diagram so I'm hoping its just a case of needing some time to steady out.

It doesn't need time. Have you done the zero current calibration?

 

[gregcope]

I have a few years of experience with two of them, and frankly, I don't like them. They are good ammeters (and that is a useful function), but the way they calculate state of charge doesn't work well, and is prone to dangerous errors (overstating the real state of charge).

I am sure you have, but have you set them up properly according to this;

http://www.pbase.com/mainecruising/programming_a_battery_monitor

I do take the % charge with a pinch of salt. It is a guide at best. I would assume that of any battery monitor as a digital representation of a chemical / physical thing, with so many variables is never going to be 100%.

I underestimate my capacity (Set for 200AH instead of nominal battery size of 240AH).

 

[Ceirwan]

It doesn't need time. Have you done the zero current calibration?

No I hadn't realied there was one.
I only had 5 mins with it after i finished intallation before I left the boat. I'll read up on the manual when I'm next onboard.

 

[SimonP85]

Thanks again for the replies. BMV-702 ordered and plans to install it this weekend!

 

[Ceirwan]

It doesn't need time. Have you done the zero current calibration?

Had a search through the manual, couldn't find a zero current calibration, do you know the procedure?

 

[knuterikt]

Had a search through the manual, couldn't find a zero current calibration, do you know the procedure?

from manual, section 4.2.1

09. Zero current calibration
If the BMV reads a non-zero current even when there is no load and the battery is not being charged, this option can be used to calibrate the zero reading.Ensure that there really is no current flowing into or out of the battery (disconnect the cable between the load and the shunt), then press SELECT.

Make certain that you have no consumption, heaters should be connected without going over the battery switch.

Link to manual https://www.victronenergy.com/upload/documents/Manual-BMV-700-700H-702-EN-NL-FR-DE-ES-SE-PT-IT.pdf

 

[Ceirwan]

Thanks!