Charging Trojan T105 batteries

PabloxPablox Registered Users Posts: 3
Just stumbled on this forum, and although slightly off topic, someone maybe able to help.
I am about to purchase 4 of Trojan T105 deep cycle batteries to put in a rarely used JLG access platform.
i.e 24v (4 x 6v 225ah batteries)
I will be charging the batteries after use, to 100% by the normal built in mains charger, but given the cost of the batteries, I was wondering what wattage solar panel and what controller etc. could I leave permanently connected to keep the batteries in good shape.
I live in Ireland (not very sunny lol).

Comments

  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Charging Trojan T105 batteries

    Welcome to the forum.

    Trojan is a sort of industry standard battery, but they have some fairly high requirements for charging. For instance in a 24 Volt system they recommend an Absorb Voltage of 29.6. In order to achieve that you need a programmable charge controller as most of the inexpensive ones will not go beyond 28.8 for 24 Volt systems. Further to that you'd want a peak current around 10% of the 20 hour capacity, and that means 22.5 Amps. To get that from solar you are looking at:

    22.5 * 24 / 0.77 = 700 Watt array and a good MPPT type charge controller. Plus a sunny day. :D
    If you don't have the sunshine you can increase the array size (more money) and limit the maximum output of the controller so that it doesn't go over on a good day.

    This is, btw, very similar to what I have on my system.
  • PhotowhitPhotowhit Solar Expert Posts: 5,653 ✭✭✭✭✭
    Re: Charging Trojan T105 batteries

    Is this a scissor lift? Doesn't it have a battery maintainer built in?

    If so park it in the shade and leave plugged in and check the water every Monday when you come into work...
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • PabloxPablox Registered Users Posts: 3
    Re: Charging Trojan T105 batteries

    Thanks for the replies, it is a scissor lift, with a built in charger.
    I only have it for home use and it might be a month or two between charges, so I thought rather than keeping it plugged in, a small solar panel might suffice, as I would only need to replenish the batteries self discharge.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Charging Trojan T105 batteries
    Pablox wrote: »
    Thanks for the replies, it is a scissor lift, with a built in charger.
    I only have it for home use and it might be a month or two between charges, so I thought rather than keeping it plugged in, a small solar panel might suffice, as I would only need to replenish the batteries self discharge.

    That is a different situation. Maintenance charging is much easier to accomplish and does not require as much panel or controller. You really only need current around 1-2%, or about 5 Amps. That would only need about 175 Watts of panel (curiously, one of the Sharps I use which regrettably aren't made anymore).

    So you'd have something like this: http://www.solar-electric.com/powerup-bsp185-24-185-watt-monocrystalline-solar-panel.html
    Controlled by something like this: http://www.solar-electric.com/ss-10l.html

    With this I wouldn't worry too much about having exactly the right charging Voltage as it will more or less be keeping the battery floating rather than doing a full recharge. And very much cheaper than a total solar charging system.
  • PabloxPablox Registered Users Posts: 3
    Re: Charging Trojan T105 batteries
    That is a different situation. Maintenance charging is much easier to accomplish and does not require as much panel or controller. You really only need current around 1-2%, or about 5 Amps. That would only need about 175 Watts of panel (curiously, one of the Sharps I use which regrettably aren't made anymore).

    So you'd have something like this: http://www.solar-electric.com/powerup-bsp185-24-185-watt-monocrystalline-solar-panel.html
    Controlled by something like this: http://www.solar-electric.com/ss-10l.html

    With this I wouldn't worry too much about having exactly the right charging Voltage as it will more or less be keeping the battery floating rather than doing a full recharge. And very much cheaper than a total solar charging system.

    Thanks again, yes that's what I meant, but I didn't express it very clearly in the opening post.
    That sounds like what I need, afterI use the scissor lift, I will charge it to 100%, I just want the panel to keep the batteries in good condition until the next time, I use it.
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