No Break 12Vdc Power Supply

Discussion in 'The Projects Forum' started by axeman22, Jan 16, 2010.

  1. axeman22

    Thread Starter Active Member

    Jun 8, 2009
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    0
    Hi all,

    I would like to run my radio shack from 12Volts PS - constant & no break is what I desire. In my hot little hands I have a huge truck battery(12V) and also a GME PSE1225A, regulated at 13.8V.

    so is there is a way to 'reasonably' use the 13.8Vdc PSU in parallel.? I'd ideally like the PSU to trickle charge the Battery and as soon as mains drops off the battery runs the show. This device, the EBS-1 looks ideal in the way it works.. what would be inside it I wonder?

    my real concern is the battery... and I going to kill it? sulphation? is the 13.8Vdc not high enough - Gassing voltage is about 14V.. does I need to get it gassing? if mains falls low.. would the battery feed back into the PSU ?

    appreciate all input.. battery charging to me is a bit of a black magic..

    Thanks!
     
  2. Duane P Wetick

    Active Member

    Apr 23, 2009
    408
    19
    You sound like one of my old colleagues who constructed a huge 12 Vdc power source and had 2 big brass bolts fitted to the back of his workbench with a sign:
    12 Volts, NO MATTER WHAT!
    It looks like the EBS-1 provides a variable trickle charge of 1-4 amps. @ 13.8 Vdc. depending on how many 12 V bulbs you use. Float charging is typically 2.2 V/ cell x 6 = 13.2 Vdc, Full charging at 2.4 x 6 = 14.4 Vdc. Some adjustability is desired in these figures because of battery construction and temperatures. I would monitor the electrolyte specific gravity (if possible) and maybe the temperature too when charging. Check out the other battery threads in this forum.

    Cheers, DPW [ Everyone's knowledge is in-complete...Albert Einstein]
     
  3. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Hi Axeman,

    Try to find the manufacturer's datasheet for your specific battery. Charge procedures can vary significantly across even the same manufacturer's battery lines, even if they are of similar chemistry. If you want the longest service life from your battery, the manufacturer's recommendations should be followed.

    The use of lamps to program the charge current is somewhat clever, but there is no provision for occasional maintenance "equalization" charging. This is a deliberate overcharge for a period of an hour or two, that does cause some gassing, but the idea is to stir up the electrolyte and help remove plate sulphation so that it can re-combine with the electrolyte.
     
  4. axeman22

    Thread Starter Active Member

    Jun 8, 2009
    53
    0
    Any chance someone might sketch up a basic cct.. I don't get how the lamps would be used, perhaps I'm over complicating!

    also - would it be pure no break. years ago I used to run everything of a battery.. and had a 4 amp trickle charger accross that, worked a treat. This though would be somewhat different I'm thinking.. - slightly confussed, perhaps at the simplicity :)
     
  5. SgtWookie

    Expert

    Jul 17, 2007
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    They don't have any specs on the EBS-1.

    Where's the manufacturer's datasheet for your battery?

    We're not going to get very far without that.
     
  6. axeman22

    Thread Starter Active Member

    Jun 8, 2009
    53
    0
    This is the best specs I could find..

    EBS-1

    battery is a second hand one with no markings. It's 12V Lead Acid, very large. One half of a truck battery 24V pair. 1100CCA.

    reading some more on the EBS-1

    seeing the relay and the word SWITCH means to me that it's not true NO-BREAK 12Vdc .. which is what I'm after. I guess it would be very fast and there is a reasonable amount of capacitance in most devices and an ability to withstand a 100mS break.. but, not ideal. In the old days I just had a Battery, everything wires straight from that.. and a 4Amp trickle charger. It was proably so wrong in many ways but it works well for many years with little to no maintenance, plus I could buy a cheap charger (~$50 AUD) and a cheap battery (second hand batts were free in those days!) and the 'system' would easily supply a nice clean DC to my radio's etc.. I could pull 12Vdc @ 10Amps out of it .. for reasonable periods.. and then it would recover overnight etc. Plus, what was best was that I always had power - NO-BREAK.

    So now I have a suitable battery.. and I have this lovely big power supply.. which, when I use this battery will be of little use .. so I was just thinking, surely there is some relatively simply way I can make these two work in complementary harmony, ultimately giving me a No-Break system.
     
    Last edited: Jan 16, 2010
  7. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    If it is a truck battery, then it is not suited to being a deep-cycle battery.

    More importantly, it will vent hydrogen and oxygen gases during the necessary equalization cycle, along with small amount of venting during normal charging. It will not be safe to have such a battery indoors, as the gases are explosive.
     
  8. axeman22

    Thread Starter Active Member

    Jun 8, 2009
    53
    0
    yep.. but the challenge is that it's cheap, and I've done t before with great success. The old theory/versus practice discussion...

    and yes, it will be outside so nice and safe. 13.8V Power Supply will be inside. there is a cable gland in the brick wall to the outside, battery is located about 3ft away - perhaps 5-6 ft in terms of cable length.

    c'mon Wookie.. we can make it work, even if the battery cacks up and dies a slow death it's not the end of the world.. it was cheap and I could get about as much back for raw materiel recycling value.
     
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