Charging T-105's

Options
System
System Posts: 2,511 admin
in Advanced Solar Electric Technical Forum #1
I have a question I hope you guys can help with

I have 2 T-105's in my DIY Camper that I want to charge with Solar Panels and the vehicle's Alternator (160 amp alternator)

Connecting the solar Panels is no problem,

but......How would I connect my Xantrex C60 Charge controller to my vehicle's alternator for battery charging when it's cloudy/nighttime

It seems that if I just connected the C60 to my 160 amp alternator it would provide too much amperage to the C60, or would the C60 just pull the power it needs

Thanks
· Share on Twitter

Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    #2
    Options
    Re: Charging T-105's

    If I understand you correctly, Just connect the C60 directly to your battery bank (short, heavy wire runs, protected by appropriate fuse/breaker). C60 should be close to the battery banks--You do not want long/light gauge wire between the C60 and the battery bank (too much voltage drop can dramatically slow battery charging--Can also be an issue with the wiring between the alternator and the battery bank).

    Next question, is this the only battery bank or do you have a house and vehicle battery bank? And are you using a isolation switch between the two battery banks?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
    · Share on Twitter
  • System2
    System2 Posts: 6,290 admin
    #3
    Options
    Re: Charging T-105's
    BB. wrote: »
    If I understand you correctly, Just connect the C60 directly to your battery bank (short, heavy wire runs, protected by appropriate fuse/breaker). C60 should be close to the battery banks--You do not want long/light gauge wire between the C60 and the battery bank (too much voltage drop can dramatically slow battery charging--Can also be an issue with the wiring between the alternator and the battery bank).

    Next question, is this the only battery bank or do you have a house and vehicle battery bank? And are you using a isolation switch between the two battery banks?

    -Bill

    my camper is a converted Ford E250 van

    It has a 160 amp alternator connected to the regular starting battery under the hood.

    In the back of my van I have 2 T-105 225 Amp batteries, a trace C60 charge controller, and a 140 watt solar panel mounted on the Van's roof.

    Right now my solar system is isolated from the vehicle's electrical system

    But I would like to use the alternator to charge my T-105's because sometimes my 140 watt solar panel isn't enough to keep up with my power consumption especially on cloudy days.
    · Share on Twitter
  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    #4
    Options
    Re: Charging T-105's

    Yep... People use a battery isolator between the house and vehicle batteries. If the house battery is taken to dead--you can still start the vehicle by using an isolator.

    There are to types of Isolators (that I know of). One is big set of diodes on a heat sink. The other is a high current switch (like a starter relay).

    The diodes will cause a 1/2 volt or so voltage drop--which can really slow down battery charging (14.2 volt typical alternator - 1/2 volt = 13.7 volts--or floating the battery, not fast charging).

    A switch/relay type will turn on once you start the engine and will not have the diode junction drop. So you will get (somewhat) better/faster charging. Again, using as short and heavy cable between the vehicle battery and the house battery as practical, is important.

    The details, flooded cell deep cycle batteries need ~14.5-14.8 volts or a bit higher (especially in sub freezing weather) to charge quickly and over 15 volts to equalize. Neither voltages are standard alternators setup to deliver. You might find a marine alternator that can be adjusted to give appropriate charging voltages for deep cycle--But then you run the risk of over voltaging your vehicle electrical system... >14.5 volts or so, and you can damage the vehicle electronics.

    Also, when recharging from your engine--it is fairly inefficient--Especially if you are idling the engine to recharge. Less of an issue if you are driving while recharging.

    If you do spend lots of time parked and needing to recharge--You might be better off getting a small Honda eu1000i genset + AC deep cycle battery charger to keep the battery bank charged. It will use less fuel, less wear on your vehicle engine, and do a better job of recharging.

    But hauling an extra generator and battery charger may not be practical or cost effective for you...

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

Categories