more batteries + more power, yes/no

I know this is going to get a bunch of "you are a dumb newbie" replies, but i accepet that. I just need a straight answer, with no poliitcs or value judgments. I am not well educated in batteries and stuff. so,. If one battery produces X number of amps over Y minutes, do four batteries produce four times X amps or four times X minutes? thanks. PG

Comments

  • RCinFLARCinFLA Solar Expert Posts: 1,280 ✭✭✭
    Re: more batteries + more power, yes/no
    PHilipG wrote: »
    I know this is going to get a bunch of "you are a dumb newbie" replies, but i accepet that. I just need a straight answer, with no poliitcs or value judgments. I am not well educated in batteries and stuff. so,. If one battery produces X number of amps over Y minutes, do four batteries produce four times X amps or four times X minutes? thanks. PG

    Likely more then 4x but depends on current. The same amount of current from four batteries means 25% of original current on single battery. Battery capacity in yielded amp-hours drops the heavier it's load.

    The standard reference for AH is capacity rated for a 20 hour total discharge. Discharge it at 5X this amount and a typical lead-acid gets about 65% of the 20 hr AH rate.

    For example a 100 AH lead acid battery,

    At 5 amp discharge rate would yield 100 AH capacity for 20 hours to total discharge.

    At 25 amp discharge rate would yield about 65 AH, about 2.6 hours to total discharge.

    AGM lead acid batteries have a bit less degradation in capacity at higher discharge current.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: more batteries + more power, yes/no
    PHilipG wrote: »
    I know this is going to get a bunch of "you are a dumb newbie" replies, but i accepet that. I just need a straight answer, with no poliitcs or value judgments. I am not well educated in batteries and stuff. so,. If one battery produces X number of amps over Y minutes, do four batteries produce four times X amps or four times X minutes? thanks. PG

    All other factors being equal, 4X the same battery equals 4X the potential power. As in:

    One 100 Amp hour 12 Volt battery = roughly 1200 Watt hours
    Four 100 Amp hour 12 Volt batteries = roughly 4800 Watt hours

    And we do not allow "you are a dumb newbie" replies here. No one was born knowing anything; everyone has to learn. :D
  • waynefromnscanadawaynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: more batteries + more power, yes/no
    PHilipG wrote: »
    If one battery produces X number of amps over Y minutes, do four batteries produce four times X amps or four times X minutes? thanks. PG

    An oversimplified answer that may help you grasp the idea, if you haven't already got it, is yes, or yes.
    Until you get a good handle on the whole thing, you can think of it these three simplified ways.

    1) Yes, if 4 batteries are connected in PARALLEL, (side by side, + to + to + to +, and - to - to - to -) you can get 4 times the current of just one battery alone. But still maintain the same voltage as one battery alone.

    2) Yes, if the batteries are connected as above, you can think of it as a source that can supply a given load for 4 times the minutes of just one battery alone.

    3) Finally, if you instead connect those batteries in SERIES, one after another (end to end so to speak), the + of the first battery to the - of the next and so on until all 4 are connected, which will leave the Negative of the first battery, and the + of the final battery for connection of your load, which will be supplied with the same amps as one battery alone, BUT, 4 times the voltage. Once you grasp those ideas, then you can add to your knowledge and understanding by digging deeper into the ideas mentioned in previous posts, re amp hours available depending on how fast you take power from those batteries etc. Hope this helps. :D
  • ggunnggunn Solar Expert Posts: 1,973 ✭✭✭
    Re: more batteries + more power, yes/no
    PHilipG wrote: »
    I know this is going to get a bunch of "you are a dumb newbie" replies, but i accepet that. I just need a straight answer, with no poliitcs or value judgments. I am not well educated in batteries and stuff. so,. If one battery produces X number of amps over Y minutes, do four batteries produce four times X amps or four times X minutes? thanks. PG

    Four times the batteries = four times the power. Four batteries in series = four times the voltage at the same current as a single battery. Four batteries in parallel = four times the current at the same voltage as a single battery. Power is voltage times current, so either way it's four times the power.
  • SevenSeven Solar Expert Posts: 292 ✭✭
    Re: more batteries + more power, yes/no

    Yes, you get 4 times as much from 4 batteries as you do one. available amps is usually referred to as amp hours. That means amps per hour.
    You will normally need 4 times as much charger to charge them back up also.
  • BB.BB. Super Moderators, Administrators Posts: 29,850 admin
    Re: more batteries + more power, yes/no
    Seven wrote: »
    Yes, you get 4 times as much from 4 batteries as you do one. available amps is usually referred to as amp hours. That means amps per hour.
    Be careful... Amps is already a rate (like miles per hour). Amp*Hours is an amount (like miles driven). Amps/Hour is the rate of change (sort of like acceleration)--and not normally used in electrical (rate of change of current and voltage are used in impedance calculations--but it is not in the amp/hour units).

    So it is said as Amp Hours, meaning Amp*Hours (like Watt*Hours--"*" meaning to multiply). It is not Amps per Hour (per is divide).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • icarusicarus Solar Expert Posts: 5,398 ✭✭✭✭
    Re: more batteries + more power, yes/no

    The short answer, in the real world, devoid of technical jargon is YES. 4 batteries translates (roughly) to 4 times as much potential power available. Doesn't matter if in series or parallel, the amount of watt/hours you can draw will be ~4 times as much. (Watt hours are what we actually consume!)

    (Not counting wiring loses etc).

    Tony
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: more batteries + more power, yes/no

    as bill said we are dealing with amp hours and as such if one were to parallel 4 batteries it has 4 times the amp hours. if your load draws 4x as much, the time it will last will be the same as the single battery with a load of 1/4 of the larger battery bank. simply 4x the capacity with a load also at 4x the draw will yield a time it'll last being the same. if you increase the capacity by 4x, but keep the load the same as that for the single battery it will last roughly 4x as long, but will be slightly more as rc pointed out due to the peukert (spelling?) effect.

    somehow i feel you are confused though and you wanted a simple straight forward answer, but is there such a thing?:confused: i will say that assuming the batteries are identical and parallel,
    4x ah capacity + 4y load current = the same time it will last as it would for a single 1x ah capacity + 1y load current.
    4x ah capacity + 1y load current = 4 times+ the time as a single 1x ah capacity battery with 1y load current.

    x=set amp hours of single battery
    y=set load current
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