NASA BM2 not showing available Amps in Battery Bank

Discussion in 'Tech/Mech General' started by Abacist, Jun 6, 2016.

  1. Abacist

    Abacist Funster

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    I have just installed a BM2 and am getting the Voltage readings for the Hab batteries and the Cab battery and am getting what is being input in amps when on charge and what is being drawn out in amps when powering something.

    However I am not getting the right hand bar graph to show the stored amp hours in the hab batteries in spite of inputting the battery bank capacity of amp hours.

    The manual talks of doing a 20 hour test on the hab batteries. Is this what I need to do for the BM2 to "learn" the capacity of the batteries by seeing a full discharge and re-charge or is there some other calibration to be done?
     
  2. Abacist

    Abacist Funster

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    I have now been able to answer my own question!

    Having input the battery bank capacity at 360 amp hours and they are fully charged when you put a load on it is then able to work out the remaining amp hours in the battery. It displays as a percentage bar graph on the right hand side and when you press the "Time" button it gives you both the percentage capacity left and the number of hours left up to a maximum of 199 hours if you have more than that left.
     
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  3. tonka

    tonka Funster Life Member

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    Out of interest have you fitted more than 120w of solar ??
    The Sargent unit can handle 120w and will smart charge both batteries as standard...So no need for a B2B charger unless you are using higher wattage panels and a seperate regulator.
     
  4. Abacist

    Abacist Funster

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    We were supposed to be touring in Europe having had the van for sale with no takers so I did a quick fix of stuff I can remove again quickly which was 2 additional 180ah batteries, B 2 B charger and 1500 watt inverter and a few 12 volt sockets so its all independent of the AutoTrail stuff, solar panel and original 2 hab batteries. I may well fit more solar to feed the new setup if we decide to keep the van or one to feed the new setup and one to add to the existing solar panel to charge the original batteries.

    I think what I have done is similar to what Hymer do although theirs is via their shaudt system to an inverter and hab batteries.

    Adding more solar would make us self sufficient if we stayed put in one place with no EHU and the B 2 B will keep us charged up when we are on the move and when there is no sun!
     
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