add agms

I have an 06 sprinter van set up as a limo by midwest auto designs and am making it camping able. My van came with an aux. battery under the passenger seat that I have isolated from the starter battery that provides power to the inverter for a flat screen, xbox, dvdcd player, 3 circular roof vents with fans, overhead lights that I have changed from halogen to led,s. I am adding two EON agm,s group 31, 1150 cca, 205 minutes reserve cap. each. My aux. is a vented lead acid VARTA 12 volt 100 amp hour battery for semi traction?, not suitable for jump starts, A 004 541 34 01. I have two arco PV panels that put out 41 watts each and 22 to 23 volts in direct sun. I am adding a 12 volt frig like the ARB or ENGEL or Whynter[ any info on this?] 85 quart size to be run at the frig mode. I am also adding an ESPAR D5 hydronic for cold weather engine protection and warm cabin air. I believe the frig will use less amps if it can be run at 24 volts that I could run on the agm,s or the aux. too. I believe I will need more PV panels and hopefully not more batteries[ these EONS are $330 each plus tax and are rated for dual use as deep cycle and starter capabilities. I hope to use these 2 as a backup for my starter battery if I ever need them. My concerns are about charging these two different battery types from the alternator while running down the road and charging them from my roof rack PV,s. I intend to be able to camp for extended periods independent of the ignition and motor. I do have a marine battery switch[ Guest Selector Switch with Alternator Field Disconnect, 230 amps continuous,345 amps momentary. There is a lot going on here and my local auto electric tech doesn't do any PV stuff. I am trying to buy whatever I can ahead of time so I don't have to pay retail for controllers,wiring etc. from him. The 12 volt frig will pull from 1.5 to less that 3 amp/hours. Any suggestions for setting this up and protecting these high buck agm,s from over charging would be a great help to me and my local tech. Hope you can help. Thanks.

Comments

  • BB.BB. Super Moderators, Administrators Posts: 32,005 admin
    Re: add agms

    I will break up your post into sections so it is easier to respond too:
    I have an 06 sprinter van set up as a limo by midwest auto designs and am making it camping able. My van came with an aux. battery under the passenger seat that I have isolated from the starter battery that provides power to the inverter for a flat screen, xbox, dvdcd player, 3 circular roof vents with fans, overhead lights that I have changed from halogen to led,s.

    We really need the power requirements... Watts, Hours per day, etc. Also would be helpful to know where you will be camping and what seasons (amount of sunlight).

    Assuming 250 watts of load 3.5 hours per day, and 1 day of no sun / 50% maximum discharge... Works out to around 420 watts of solar panels and 172 AH @ 12 volt battery bank.
    I am adding two EON agm,s group 31, 1150 cca, 205 minutes reserve cap. each. My aux. is a vented lead acid VARTA 12 volt 100 amp hour battery for semi traction?, not suitable for jump starts, A 004 541 34 01.
    It is not a great idea to mix type, brand, size of batteries into one battery bank. It is difficult to get them to properly share current/load while charging/discharging.
    I have two arco PV panels that put out 41 watts each and 22 to 23 volts in direct sun. I am adding a 12 volt frig like the ARB or ENGEL or Whynter[ any info on this?] 85 quart size to be run at the frig mode. I am also adding an ESPAR D5 hydronic for cold weather engine protection and warm cabin air. I believe the frig will use less amps if it can be run at 24 volts that I could run on the agm,s or the aux. too.
    82 watts worth of panels will, in the US Southwest, 9 months of the year, only output around 160 WH of AC power per day... That is not very much power.

    Adding an electric refrigerator will up the amount of panels/battery bank significantly. If you are going to have propane anyway--looking at a 2 or 3 way propane/electric refrigerator may be a batter fit--unless you have enough room for more panels/battery bank.
    I believe I will need more PV panels and hopefully not more batteries[ these EONS are $330 each plus tax and are rated for dual use as deep cycle and starter capabilities. I hope to use these 2 as a backup for my starter battery if I ever need them. My concerns are about charging these two different battery types from the alternator while running down the road and charging them from my roof rack PV,s.

    Slow down and lets understand your loads/requirements first. Measuring with a kill-a-watt meter (for AC power) and/or one of these for DC Amp*Hour/Watt*Hour measurements would be helpful.
    I intend to be able to camp for extended periods independent of the ignition and motor. I do have a marine battery switch[ Guest Selector Switch with Alternator Field Disconnect, 230 amps continuous,345 amps momentary.
    Really need to look at conservation--smallest/low power TV/Computer/etc. Possibly shifting to propane fridge. How many panels can you practically mount on your van? Can you set them up to tilt?
    There is a lot going on here and my local auto electric tech doesn't do any PV stuff. I am trying to buy whatever I can ahead of time so I don't have to pay retail for controllers,wiring etc. from him.

    If you can guide him with what you need (wiring, components, installation direction)--you can make it work OK. But you are probably right in studying up first for yourself. Solar is not that much different--but there are lots of trade offs ($$$, conservation, etc.).
    The 12 volt frig will pull from 1.5 to less that 3 amp/hours. Any suggestions for setting this up and protecting these high buck agm,s from over charging would be a great help to me and my local tech. Hope you can help. Thanks.
    The fridge, using your numbers:
    • 3 amps * 24 hours * 12 volts = 864 Watt*Hours per day
    That is approaching the load of a good sized home Energy Star Rated refrigerator--and would need 400-500 watts of solar panels and 100-200 AH of batteries just itself.

    Again, lots of research ahead.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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