Truck Camper panel/charger/battery wiring....

I'm looking at putting 4 210W panels on my truck camper. They will be connected to an MPPT controller and 4 batteries that will stay in the bed of the pickup. The batteries will be connected to the 2500W inverted inside the cab and then to an electronic 165A isolator, fuse, and the dual truck batteries. The camper has a battery internal to it. The camper connects to the truck with a 7-way that connects to a converter that keeps the onboard battery charged and provides 12V fusing and 110V breakers inside the camper. I can run the AC stuff in the camper off the inverter fairly easily now using only the truck batteries (in other words, the 12V truck batteries run the inverter that runs the converter/12V/110V stuff in the camper).

My question is this: When I put the solar/4 deep cycle batteries/MPPT controller in, how would the wiring go? I'm thinking truck batteries > isolator > deep cycle batteries/inverter. Solar on the camper connects to the MPPT and then to the batteries. Will this work (truck alternator charging the batteries from one end through the isolator and solar charging batteries through the MPPT from the other end?

Am I confused yet?

Comments

  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: Truck Camper panel/charger/battery wiring....

    Am I confused yet?

    I am.

    The engine starting battery should always be isolated, and never used for "house" purposes. It is permissible to use an "isolator device", so when the engine is running, it is allowed to charge the "house" battery bank. BUT, the vehicle alternator will take nearly 20 or 30 hours run time, to fully charge the house batteries. But it's good for a boost charge while going to the store and back.

    Your "converter" is likely a 120VAC to 13VDC power supply, it may charge batteries, or not. No standard exists. It may sometimes have a 12V to 120VAC inverter built in, but again, no standard exists.

    Your solar, thru the MPPT controller, should only charge a matched set of batteries, don't try to mix old and new batteries, the old ones will quickly cause the new ones to age prematurely.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • sheriffav8r
    sheriffav8r Registered Users Posts: 10
    Re: Truck Camper panel/charger/battery wiring....

    I agree. The isolator is isolating the truck battery from the "house" batteries and inverter. The converter is a low dollar model that keeps the house battery charged and provides 12VDC fused and 120VAC passthrough breakered power to the camper.

    All batteries in each bank are alike and will be charged together (2 truck batteries from the alternator and 4 batteries from the solar array/alternator). I'm just trying to make sure I'm not going to have a problem charging the house batteries from the MPPT charger/solar array while the vehicle is running (through the alternator). In other words, I've got 12VDC power to the batteries from the alternator and 12VDC power coming in from the MPPT controller/charger simultaneously. They each connect to the house battery bank at the same point. Problems?
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Truck Camper panel/charger/battery wiring....

    Equalization voltage is typically around 15+ volts... That is pretty high for a vehicle battery and may cause it to overcharge (and use a lot of water--even if it is maintenance free).

    Also, 15+ volts could damage the vehicle's electronics, normally they see around ~13.6-14.2 volts maximum. High deep cycle charging voltages are known to damage some 12 volt vehicle accessories (such as computer 12 volt adapters, etc.).

    As long as the Charge Controller is not set to equalize the battery bank while the vehicle is running (isolator connecting the two banks)--you should be OK.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • dwh
    dwh Solar Expert Posts: 1,341 ✭✭✭
    Re: Truck Camper panel/charger/battery wiring....
    I agree. The isolator is isolating the truck battery from the "house" batteries and inverter. The converter is a low dollar model that keeps the house battery charged and provides 12VDC fused and 120VAC passthrough breakered power to the camper.

    All batteries in each bank are alike and will be charged together (2 truck batteries from the alternator and 4 batteries from the solar array/alternator). I'm just trying to make sure I'm not going to have a problem charging the house batteries from the MPPT charger/solar array while the vehicle is running (through the alternator). In other words, I've got 12VDC power to the batteries from the alternator and 12VDC power coming in from the MPPT controller/charger simultaneously. They each connect to the house battery bank at the same point. Problems?


    Problems:

    1)
    The incoming voltage from either the alternator or the converter/charger to the battery will probably fool the MPPT into not working right - which may or may not even be a big deal but you need to be aware of it.

    MPPT tracks the voltage of the battery, and uses that to decide how much to adjust the voltage coming from the PV panels. The "maximum power point" is some point not far over the battery's voltage at which the battery will accept current most efficiently.

    So, a battery that is at say, 13.2v might accept voltage most efficiently if the incoming voltage is say, 13.7v (that MPP number is just a WAG - for all I know it could be 14.613v).

    If your alternator is putting 14.3v into the battery side, then the MPPT will think that the battery is at 14.3v and will adjust its charging voltage to whatever the MPP of 14.3v is, instead of setting the MPP to whatever is best to charge a battery which is actually at 13.2v


    2)
    SmartGauge doesn't like "diode-type" isolators - and for what I consider to be pretty good reasons (just FYI, but it caused me to re-think my camper's battery charging scheme):

    http://www.smartgauge.co.uk/diodes.html





    I'm setting mine up first without the PV, then I'll add the PV later. I'll be using 4 105ah aux batteries, and 1 engine start battery (possibly two later).

    I will be using an Iota battery charger/converter (probably the 45a unit for the 420ah AGM battery bank...which is actually a bit much but I'll be using it to supply 12v loads as well) in two-stage mode to charge the aux batteries, and a Battery MINDer to charge the engine battery. These will be powered either by generator or shore power.

    http://store.solar-electric.com/bach2.html

    http://www.batteryminders.com/batterycharger/catalog/BatteryMINDer-12-Volt-2-4-or-8-Amp-Charger-Maintainer-Desulf-p-16133.html

    I will also very likely add a desulphator to my aux bank:

    http://www.batteryminders.com/batterycharger/catalog/BatteryMINDer-OnBoard-Battery-Restorer-Conditioner-12-Volt-With-p-16148.html


    My camper already has a split-charge relay (a type of battery isolator, but different than a diode-type), like this but without the microprocessor control:

    http://www.powerstream.com/battery-isolator.htm

    I will be keeping the split-charge relay, which ties both the engine and aux batteries together whenever the alternator is putting out voltage. This is due to what I read here:

    http://www.smartgauge.co.uk/nosurge2.html



    Then, when I add the PV, I'll be using a 30a MPPT charge controller (probably MorningStar SunSaver MPPT - I hear they are coming out with a 30a unit) for the aux bank, and also tapping off a second charge controller to charge the engine bank. Something like this:

    http://store.solar-electric.com/ss-6.html

    It's not MPPT, but that's okay; for the most part the engine battery is going to need little to no charging anyway.


    Once I install the PV I'm planning on re-wiring the split-charge relay to that it is manually operated. Right now, it's energized automatically whenever the alternator is putting out voltage, but later I will probably want it rigged so that I have to hit a switch to tie the banks together.

    That way I *can* use the alternator to dump voltage to the aux bank if I want (simple on/off switch added to the existing wiring), and I *can* use the aux bank to jump-start the engine (momentary switch powered by aux bank) if I want - but unless I choose it, the banks will remain separated.
  • sheriffav8r
    sheriffav8r Registered Users Posts: 10
    Re: Truck Camper panel/charger/battery wiring....

    Good info and a lot to chew on. I'm also going to get the battery bank set up first and hopefully add solar later. Might just have to manually isolate the system myself....