Wiring Batteries in Series

Your question makes no sense.

Both series and parallel would be wired as a circuit or they wouldn't do anything.

A cell that makes up a battery has around 1.5 volts. Connecting cells in series adds the voltage. So a 12 volt car battery has 8 cells in series(start at a terminal and connect positive to negative, positive to negative and so on eight times until you get to the other terminal.)--It doesn't have to end there. If you connect another 12volt battery positive to negative, you will have 24 volts across the open terminals, and another-- 36volts across them, another-- 48volts, then add a 6volt battery to the series--54volts of potential difference.

If you connect them in parallel(hook positives together and negatives together), then you double the capacity without increasing the voltage.

What we call batteries--D's C's AA's AAA"s are all really just cells at 1.5volts--Their capacities are reflected with size of the cell. Just dissimilar metals separated by acid or paste.

There is a lot to them and you should check into it for yourself--Cheers

Car batts wet lead acid have 2v nom x 6 cells = 12v nom- fully charged at 14.25v rate- sitting volts = 12.6v- sg = 1.260. 8 cells would be true if dry cells used to make 12v batt pack- cheers.

Hello Kilgore Trout

V"....So a 12 volt car battery has 8 cells in series(start at a terminal and connect positive to negative, positive to negative and so on eight times until you get to the other terminal.)....">

Just to advise that all 12V car batteries I have ever seen, are lead-acid type with nominal 2Volts per cell, and six cells are connected in series to arrive at the nominal 12 Volts of that car battery.

Kind Regards....

Hello FKIA

just a good side bar to your above post.

Actually car style lead-acid batteries when fully charged, are 2.2 volts per cell.

Thus the fully charged car style lead-acid battery voltage is really 6 x 2.2 = 13.2 Volts DC.

The Voltage rating for electrical accessories to run in a car "12 Volt" system, is 13.6 Volts DC.

Car alternator regulators are normally fixed at 14.2 Volts DC Output.

Truck alternator regulators are normally fixed at 14.7 Volts DC output.

As you may realize, the Alternator regulator settings must be higher than the fully charged battery voltage, to allow for the full series connected circuit resistance, battery (cells) individual internal resistance, and ensure that charging current flows, to charge the battery.

There is a good page re these cells, here: http://en.wikipedia.org/wiki/Lead-acid_battery

The car lead-acid battery normally has acid of specific gravity of 1.300 approx.

Large telephone exchange lead-acid batteries, each weighing over 3.5 tons per cell, had the specific gravity much lower, with a fully charged cell SG of 1.285, and these cells commonly lasted for well over 30 years, because of daily checking, and regular maintenance.

24 large telephone exchange lead-acid cells gave 50 Volts DC, with a 25th cell being able to be "switched in" during a power cut, if the Exchange auto-start emergency generator failed to start.

These telephone exchange lead-acid batteries could run an exchange for some 8 hours, and there was a second identical bank which could be switched on, also with the extra 25th cell.

Thus in case of power failure, it normally gave some 15+ hours, for a skid-mounted emergency alternator to be connected to the exchange mains input, if the local emergency alternator failed to start.

Also refer from:http://www.buchanan1.net/lead_acid.shtml

<"....

Self discharge

According to the Yuasa book, conventional lead-acid batteries discharge at a rate of 1% per day at 77 degrees Fahrenheit. That means that in a bit more than three months, your battery is dead. Faster if your bike/car draws some current when not running, which many modern vehicles do.

....">

Kind Regards....

good afternoon sparky, as usual your textbook answer is smack on but, this is one time in my humbled opinion added info mught help.

as usual my adding of a experienced based scenario might help get my thinking across to the rest of the readers.

i had at one time a opportunity to become involved in the demolition of what was a decommed central dispatch station for a alarm provider. in the basement was a HUGE pile of B batteries so i took them to play around with as the voltage was right for the magnetic induction coil experiments i was working on at the time. not knowing that putting the positive to positive and negative to negative on each of the four dry celled batteries was not a good idea i did that.

fortunately my hands were not burned by the light guaged wire insulation as it melted and went up in flames, the smell of the sulphated batteries plus the boom of each cell exploding was enoigh to tell me that was not a good idea don't do it again. getting the tar and lead off the shop floor was not a easy job, my family was most unwilling to accept the explanations offered.

'da ber

Thanks Sparkstation and FKIA for the corrections--And of course, all this free information.

Sparkstation, with all due respect and not meaning to disparage you personally, the specific gravity you give are not the usual values used for normal consumer batteries. Your link to wikipedia gives data that refers to sealed Gel or AGM batteries and the voltage are not exactly the same as for flooded batteries. The other link provided by another poster give the following Temperature: 77 degrees Fahrenheit
Percent Hydrometer Unloaded
charge reading voltage
100 1.265 12.63
75 1.210 12.30
50 1.160 12.00
25 1.120 11.76

As you can see a S.G. reading of 1.265 is the norm. ( at 77F temperature) From your post it appears that you are using data for telephone exchange back up system batteries as your guideline. These are not the norm and the manufactures use different strength electrolytes compared to the normal consumer or even industrial batteries most people are likely to encounter.

It should also be noted that S.G. reading are temperature related as clearly shown in the link provided. A reading of 1.300 SG would most often indicate a too strong mix of sulphuric acid. Monthly self discharge is dependent on the alloy used in the plate grid. Recently several new brands have come on the market that use something else. OPTIMA uses a spiral roll construction which is completely different and has much better storage characteristics. Much lower self discharge characteristics. Your mention of regulator set point may well be true for NZ but in North America where "no maintenance" batteries are becoming the norm in automobiles, regulators are now set for 13.8V ( at room temp reference) since this does not cause the batteries to overheat duo to over charging. Being sealed these batteries will self destruct if charged at 14.2V or higher. Another curious detail has to do with continental origin. In correspondence with Indian and European battery manufacturers I discovered that Indian batteries are typically of superior design and quality compared to North American batteries. They also have greater SG values for some of their product. Most European products are used in more northerly latitudes with aveage cooler ambient temps and this reflect their recommended values. For the southerly latitudes and warmer ambient temps corrections must be made.

Sparky,

Many years ago, when I went to work for Western Electric installing central office equipment in the Los Angeles Long Lines Office, I helped install cabling from one of the upper floors to the battery room.

What folks don't realize is those batteries were composed of plates sitting in huge glass containers, each set of plates and container composing one cell.

Those cells were so large that maintenance, on occasion, consisted of lifting the cells out with an overhead crane, pumping the acid out, and then getting into the cell to remove precipitate and other foreign matter and then putting the plates back in, replacing plates when necessary, and then filling back up with acid.

We are here talking about a long lines office that if I remember correctly was nine or ten stories.

Today, with solid state, such an office is replaced by a few bays of gear and maybe a ten foot rack of deep discharge cells not much different in appearance from an auto or truck battery.

Also, in terms of providing a picture of what battery technology used to look like, batteries used on farms in conjunction with windmill generators (Is there anything new under the sun) before national electrification, were made of hard rubber cases, three or six cells to the case, and the top cover holding the plates was set down in and sealed in place with pitch or tar.

Like the huge phone system batteries those units could be serviced by using a hot knife to cut through the pitch enabling the plates to be lifted out, the acid removed along with detritus, and then reassembled with fresh acid and new plates where needed.

Because of our throwaway culture folks don't realize that the failure of their car battery is often nothing more than plates being shorted by precipitate falling to the bottom of the cells.

Lets call this post Jack's lecture on historic battery culture.

j.

G,day Jack- the batts of cars fail for many reasons- the most common being failure of a conn in 1 cell to the series total- resulting in insuff current to starter motor to actually start the car etc- my Dad ran a 1937 Chev with a starter handle- so even tho the starter motor wouldn't crank, 1 flick of the crank would start the ute!. I have done this myself- out in the bush- fit a dog to crank end- adjust clearance for handle to mate- & away you go!. The modern car/batt/start sys is throw away by design!.

Hi Sparky

Your response was very clear but do you think guest will appreciate the answer considering the way the question was framed.possibly you have helped.

Perhaps guest will answer and explain his understanding of this assuming he is tracking the forum.

One way you get high volts and low amps the other way you get hig amps with low volts.

OH YA!!!!.b-e-e-g mess-y!!!! ba-d-d-d-d-e-r st-i-n-k-y!!!!

when the ends are touched to get a spark and see if the batteries are still useable it becomes a great way to melt copper wires together so 22ga. can be turned into 18ga or maybe even 14 ga.

'da ber

Hi, Guest!

Sometimes, as engineers who have learned all this stuff a long time ago, we forget that an easy explanation is the best answer to a question.

THE SIMPLE ANSWER TO YOUR QUESTION IS

that when you use one or more batteries to power something, the battery or batteries are a part of a circuit. The word 'circuit' is similar to the word 'circle'.

The circuit is just a circle of power.

Power goes from the front end of the batteries, through the LOAD, which is the thing the batteries are powering, such as a light bulb or a motor, and then back into the batteries on their back end.

Some people maintain that the 'front end' of a battery is its positive side, and some people that the 'front end' is its negative side. It doesn't matter, though, because once the power of a battery is sent through a Load and back into the battery again, a CIRCUIT (circle) has been completed.

Batteries are typically composed of cells.

A single cell is just like a single battery that you can put into a flashlight, and it has a power of 1 1/2 VOLTS.

[A volt is what happens between one end of a battery and the other end when it is alive and can produce power. A volt is also called a 'differential'. This means that the difference between nothing when only one end of the battery is used and something when both ends are used is measured in volts.

The differential, or Voltage of a single cell battery that you can buy in the store is normally 1 1/2 volts.

There are two ways to arrange more than one battery in a circuit, and if you think about it, you can see what they are:

1. You can place the batteries end-to-end, with positive terminals touching negative terminals touching positive terminals. If you do that, the batteries will add up their power, which is, as has been explained, measured in VOLTS.

For example, if you place two batteries in a flashlight, each battery gives 1-1/2 volts and the flashlight adds up to a (1-1/2 + 1-1/2)= 3-volt flashlight. This is called SERIES, because all the batteries are lined up in a series, which you can see in the diagram "SERIES" below.

2. You can also use a bunch of batteries as though they are one battery. This is done by connecting all the positive terminals together. The the power is sent through the LOAD. The Parallel circuit finishes as it goes back into all the negative terminals connected to all the other negative terminals.

In the diagram, it looks like all the batteries have been lined up parallel to each other. Lining them up this way makes connecting all of the 'LIKE' terminals together easy.

So this kind of circuit is called a parallel circuit. Since the batteries don't have a chance to line up and thus add up in a parallel circuit, the voltage remains the same as if you are using only one battery.

However, the batteries provide more "push" to the power this way, because you have lots of batteries doing the 'pushing' of the power and only a little bit of power to push.

The "pushing" is called a CURRENT, and it is measured in amperes, or "Amps". If, for example you had 3 batteries of 1 1/2 Volts each capable of one amp of power, and you put them into a circuit in a parallel configuration as in the drawing below, you would only get 1 1/2 volts of power, but the 'push' of the current would be three times as strong, totalling 3 Amps.

There are two things that are important to remember about a circuit.

1. A circuit must have a LOAD. Otherwise, it is not a circuit. If you attempt to connect the two ends of a battery together without a load, the push will just go faster and faster through the battery, it will get hot, and there is a very good possibility that it will explode. People who have tried this have lost fingers and even been killed by the explosion.

2. The most useful circuits have a SWITCH. This is a connecting point along the conduit, or wires of the circuit that can be opened to stop the circuit from working, or closed to start it working. In each of the above drawings, the circuit is open, because the switch is open, and the light is OFF.

I hope this explains your question for you.

Mark

Hello

Your multiplication is incorrect.

3 x 1¹/₂ volts in series has always totalled 4¹/₂ volts, not 6 Volts.

Kind Regards....

Hi, Sparky! Hi, Guest!

The original question illustrated uncertainty about any variety of battery arrangement or circuitry. My response is intended to help a reader through the process of learning about those things in the simplest and easiest-to-understand manner.

I was a little worried about how long it looked after I finished it, but the steps and explanations are simple to follow, so I left it alone. After reading, and hopefully understanding what I offered, an enquiring mind can be helped to be able to better understand both the simple:

"Batteries (Cells) in series give the sum of the individual cells, but the maximum current is limited by the cell with the highest internal resistance (All other things being equal)"

This brings up a new part of the circuit, called RESISTANCE. Sometimes the speed and power of the amperage pushing the battery voltage through the circuit gets changed because something has been put in the way of it flowing smoothly.

For example, if the wire suddenly becomes skinnier (thinner), then the amperage has to work harder to push the voltage through the wire. The voltage bunches up and the flow becomes strained, causing the thinner wire to heat and burn up as too much amperage for the little wire tries to jam the voltage through the it.

Sometimes a special device is placed in the circuit to slow down the flow of the amperage. This device is called a "resistor".

And sometimes too many Loads, or Loads that are too big are part of a circuit. Then the resistance of the circuit becomes so big that the voltage can't be pushed all the way back to the battery in a way that the circuit is still 1-1/2 volts. Then the circuit won't work at all, (or at the most very poorly) and the battery just wears itself out trying to complete its circuit.

Resistance in a circuit is measured in "OHMS", named after a fellow called Ohm, who was the first to notice its influence in circuits.

Today, special resistance can deliberately be placed in circuits to make them do interesting things. So when you read Sparkstation's "maximum current is limited by the cell with the highest internal resistance (All other things being equal)", Sparkstation is simply writing that if one of the batteries possesses more circuitry resistance than the others in the circuit, that's the battery that might need to be kept in mind when calculating all the things: Volts, Amperes, and Ohms, in the circuit.

You will also have seen an answer by kilgore trout in response to your question. Kilgore trout was relating his response to automobile batteries, which are actually big batteries made up of little batteries inside a large box and hooked up in series. I have added a diagram so you can see how it's done:

Kilgore trout says, "Both series and parallel would be wired as a circuit or they wouldn't do anything.

A cell that makes up a battery has around 1.5 volts. Connecting cells in series adds the voltage. So a 12 volt car battery has 8 cells in series(start at a terminal and connect positive to negative, positive to negative and so on eight times until you get to the other terminal.)

Kilgore trout goes on to say, "--It doesn't have to end there. If you connect another 12volt battery positive to negative, you will have 24 volts across the open terminals, and another-- 36volts across them, another-- 48volts, then add a 6volt battery to the series--54volts of potential difference." The following shows how car batteries are made in series, and can be added together to get lots of volts, or lots of amps if added together in a parallel circuit.

Thanks, Sparkstation, for more opportunity to pursue this topic for our guest.

Mark

Hello again, MarkTheHandyman

Thank you for your reply.

The only 12Volt car battery which I have ever seen, consisted of 6 cells at the nominal 2V per cell, rather that the 8 cells at 1.5 Volts per cell you quoted above.

I do appreciate that quote was from Kilgore Trout, now I'm off to read his post.

Kind Regards....

Can you wire 12 v batteries starting in series then go to parallel??

thanks