Batteries in Series

Batteries, Chargers, and Battery Management Systems.
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markz   100 GW

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Batteries in Series

Post by markz » Jul 27 2015 9:50pm

I think I solved my own problem.

Add Voltage in Series, and add Ah in Parallel. But you add Amps in series as well BECAUSE its commulative!!! Fact!!!
Once you add up the batteries in series you get a certain sum of voltage and a sum of amps. V x A = Ah
Each battery has a Ah rating, while the output of the series cct has a Ah.
Add each battery Ah, thats the output of series cct.

If the amperage is commulative in a series cct, then you have a 1C 2A 3V battery. 100 in series = 300V 200A 600Ah.
How can the last battery at 1C 2A 3V be able to handle the throughput of 200A?




Voltage is your "Water pressure in a water pipe" voltage between 2 points is "electrical force" that would drive an electric current (measured in Amps) between 2 points.
Amperage is your "Flow rate" how many electrons pass in a time period 1 Coulomb/second.
Resistance is the "Pipe Size"

Hillhater   100 GW

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Re: Batteries in Series

Post by Hillhater » Jul 27 2015 10:10pm

No, very wrong !..you do not add the amps or Ahr in series connection, only add the volts in series.
a 100 string of 2Ahr , 3volt , 1C, ( 6 Whr) cells will result in a 300volt , 2 Ahr 1C pack but still only capable of 2 Amps
...but you would have a 600 Whr pack , as you do add wattage in series connection
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Gregory   100 kW

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Re: Batteries in Series

Post by Gregory » Jul 27 2015 10:27pm

markz wrote: V x A = Ah
Also no.

Maybe you are confusing this with power?


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teslanv   100 MW

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Re: Batteries in Series

Post by teslanv » Jul 27 2015 10:31pm

Gregory wrote:
markz wrote: V x A = Ah
Also no.

Maybe you are confusing this with power?
Right:

Amps x hours = Amp-hours. ;)

Volts x Amps = Watts

Watts x Hours = Watt-Hours
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nutnspecial   1.21 GW

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Re: Batteries in Series

Post by nutnspecial » Jul 27 2015 10:40pm

I thought this op was joking.

markz   100 GW

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Re: Batteries in Series

Post by markz » Jul 27 2015 10:54pm

Massive brain fart going on here.
P=IV & V=IR
Ah is just some rating a battery has, I guess you could calculate it, measuring whats needed.
But yes I understand Ah in series stays at whatever the single battery Ah is. V is added.
So my formula's are off, I am misplacing Ah.

Stick with V, A, C.
Still same question arises.
3V 2A 1C, 100S......200A on last battery?
Or we need the Ah rating. Hmmmmmmmm :oops: :?

It must be a full moon tonight :?

Yes thats what has to limit it. Gotta. The Ah!

Right?

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Gregory   100 kW

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Re: Batteries in Series

Post by Gregory » Jul 27 2015 11:34pm

Current in a battery is the same everywhere, 1st or last battery....same.

But look what hillhater wrote. 300V 2Ah is only going to be supplying up to 2A.
Remember it is still a 1C battery i.e. 1C x 2Ah =2A.

The watts you can use has gone up 100 times.


1) x5305 Hub Motor in a 24" Sun rim with 10G spokes, Kelly 72601 controller, 74V 10Ah Turnigy LiPo 20C Battery and CycleAnalyst
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dogman dan   100 GW

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Re: Batteries in Series

Post by dogman dan » Jul 28 2015 6:37am

Let me know by PM, if you want this whole misleading thread to vanish. We all have brain farts.

You can edit and correct your own posts.

Hillhater   100 GW

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Re: Batteries in Series

Post by Hillhater » Jul 28 2015 8:00pm

Dogman..
Don't delete the thread. As silly as it seems, there are some basic lessons for beginners to learn here about battery terminology and connections.
Otherwise , the same mistake may be repeated and the questions posed again by others.
This forum owes its existence to Justin of ebikes.ca

999zip999   100 GW

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Re: Batteries in Series

Post by 999zip999 » Jul 29 2015 2:54am

The only way to get more amps is more cells in parallel. Or higher quality cells. More amps less range.
Watt's are you looking for ? Clue !

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amberwolf   100 GW

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Re: Batteries in Series

Post by amberwolf » Jul 29 2015 3:42am

Hillhater wrote:Dogman..
Don't delete the thread. As silly as it seems, there are some basic lessons for beginners to learn here about battery terminology and connections.
Otherwise , the same mistake may be repeated and the questions posed again by others.
Unfortunately, since few (even non-noobs) ever read anything already existing before posting their own zillion threads (or will read it even if pointed to it), the same mistake *will* be repeated and the same questions posed again, and again, and again, and again. :(



But I agree, don't delete the thread.

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dogman dan   100 GW

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Re: Batteries in Series

Post by dogman dan » Jul 29 2015 6:32am

Well, the completely wrong statement in red at the top of post one bothers me. Watts are cumulative, but amps are not in series.

destro23   1 W

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Re: Batteries in Series

Post by destro23 » Jul 29 2015 8:53am

Newbie here!! good thing i found this thread! Cuz i have the mother of all questions that will hopefully clear everything up for me and a lot of new people, hopefully we can stick this example in the FAQ. I'll ask as clear as possible. and would also like to see the math for it. Please take it easy on me as i'm only a few posts new here :)

I would like to build 2 batteries:
48v 10ah
48v 20ah

using an 18650 cell Samsung 25r or 26f

Samsung 26f
Rated Voltage: 3.7v
Capacity: 2600 mAh
discharge rate: 5 amps

Samsung 25r
Rated Voltage: 3.6v
Capacity: 2500 mAh
discharge rate: 20 amps


How would you build the pack and please do the math as you go.

example: for the 26f it's 3.7v X13 cells = 48.1 volt. after that is where i start to get confused what is the AH on just those 13 cells? 13 batteries in series get the voltage up... is when you place them in parallel when you get the AH up?

If the answers can be line by line i'd appreciate it.


ok hope i made this clear enough :)

thanks and can't wait for the replies.

999zip999   100 GW

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Re: Batteries in Series

Post by 999zip999 » Jul 29 2015 11:00am

Capacity is what ah is made of. 2500 mah per cell so two equals 5,200mah or 5.2ah, three 7,800. So four in parallel is what you need 10,400mah is 10.4ah. In a 4p battery I would use 25r as the higher c-rating so should run easier and can charge faster, so should hav less stress. Plus they are on sale now. A pony and a horse can pull a cart on flat land, but when you go up a hill you want a horse or you get out and walk up the hills. As the pony would melt.

999zip999   100 GW

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Re: Batteries in Series

Post by 999zip999 » Jul 29 2015 11:23am

More cells in series = more volts.
More cells in parallel = more ah.
More ah = more available amps.
More amps = more available watts.
More watts less range.
That's a start.

destro23   1 W

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Re: Batteries in Series

Post by destro23 » Jul 29 2015 12:45pm

ok can you make a 48v 10ah pack?

13 x 3.7v = 48.1v but 13 cells lined up in a row... do you add all the mAh of all 13? or when they are in a series does the mAh stay the same? and just the voltage goes up?

999zip999   100 GW

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Re: Batteries in Series

Post by 999zip999 » Jul 29 2015 12:52pm

Mah same. Go read the thead on top of page. Battery F.A.Q. don't stop reading.

destro23   1 W

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Re: Batteries in Series

Post by destro23 » Jul 29 2015 1:05pm

ok i think i have it....

Samsung 25r
Rated Voltage: 3.6v
Capacity: 2500 mAh
discharge rate: 20 amps

in order to make a 48v 10ah pack you can do this:

I take (13) 18650 cells in series (attached to each other) times 3.6v = 46.8v OR<------ do i add another cell (14) to make it 50.4? what is "more safe"?

so i now have a 46.8v Pack that is currently 2.5AH

So In order to get it to about 10AH is to make 4 packs of 13 cells(52 batteries total, because AH multiplies in parallel not in series.


999zip999 i think i'm good now.. i did read the faq :) But needed an actual build scenario for it it sink into my brain.

Next Question... samsung 26f 5amps discharge vs samsung 25r 20amps discharge... where how does this come into play?

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