The "battery is like a capacitor" has extremely limited utility. As you overcharge most batteries you do NOT store additional charge resulting in higher terminal voltages. You incite chemical reactions that release that energy in the form of heat and the terminal voltage increases little, if at all. So, more likely, if you had two sufficiently robust batteries (say a 12 V and a 24 V battery with adequate current limiting) the final voltage would be down close to the lower voltage one as it would simply suck the energy out of the higher voltage battery and do a good imitation of a space heater.

 

If I take a thread over 5.5 years old and resurrect it with a brand new post what will my current be? More specific what would motivate me to resurrect such an old thread?

Ron

 

Consider this: Batteries are sort of similar to capacitors. They both can be charged and discharged (assuming a rechargeable battery).

I said batteries are SORT OF SIMILAR to capacitors. They BOTH can be charged and discharged (assuming a rechargeable battery. SORT OF SIMILAR. No, not identical. Capacitors are entirely different beasts from batteries as batteries are chemical based and caps are electron charge based. In both cases a battery and a capacitor have more electrons at one end than the other. And if a path is provided from the higher concentration of electrons to the lower concentration of electrons then current will flow.

This discussion is not about putting a 5000 volt 5000 amp hour battery in parallel with a coin cell battery. It's Theory we're focusing on. At least that's where I'm going with this. Assume there's no such thing as a battery that can't take an infinite voltage and theory becomes all we can discuss. So, again, two capacitors charged to different voltages WILL equalize their voltages when in parallel.

Now, if you want to compare a 2000 volt capacitor to a 16 volt capacitor and assume a starting voltage in the 2KV cap to be charged to 1.8KV then yes, there will be a rather spectacular conclusion to the experiment when you attempt to connect the 16 volt cap in parallel to the 2KV cap.

Do we really need to hash this out further? It's just theory. An attempt by the thread starter to understand his theoretical circuit. Or am I so wrong that I'm now making an utter fool of myself? I'd like to hear what others think about this. If I'm wrong I'll take my lesson and shut up.

 

what would motivate me to resurrect such an old thread?

Inadvertently I've asked a question that has been addressed before. Sometimes I fail to exercise "Due Diligence" searching out threads and just blurt out my question. Sometimes someone new has a question just like many of us may have had at some time in our early lives in the realm of electronics study. The only thing worse than asking a dumb question is to sit silent and learn nothing from it.

 

Inadvertently I've asked a question that has been addressed before. Sometimes I fail to exercise "Due Diligence" searching out threads and just blurt out my question. Sometimes someone new has a question just like many of us may have had at some time in our early lives in the realm of electronics study. The only thing worse than asking a dumb question is to sit silent and learn nothing from it.

Tony, my post was not aimed at you or you asking a question. I have also inadvertently responded to an old thread without catching the original date. Old threads need to be literally dug up as they are not on the surface. Makes me wonder why this old thread was literally dug up? What was the point?

Ron

 

@Reloadron I didn't think you were taking aim at me. I was just responding to how an old thread can be dug up. Once I scrolled down below the last box and found "Similar" threads and clicked on one and responded to a post that was nearly a year old. It happens. Oops. Probably most of us have done that.

I like this forum because it exercises my otherwise lethargic brain cells. It feels good to get them vibrating from time to time. The only problem here is that the BB's start to rattle and the neighbors complain about the noise.

[edit] Hm. Seems to have escaped me too. Johnny Radio was the one who brought it back to life. So I bet my answer to the "ORIGINAL" post will likely go unheard.

 

Tony, my post was not aimed at you or you asking a question. I have also inadvertently responded to an old thread without catching the original date. Old threads need to be literally dug up as they are not on the surface. Makes me wonder why this old thread was literally dug up? What was the point?

Ron

Digging up old threads is trivially easy. Look at the bottom of the page any time you are posting and you will see a list of "Similar Threads". This list almost always includes threads that died over a decade ago. But, especially for new users, these are the threads that AAC is recommending that you look at and so it is really easy to look at it and respond to it without realizing that it is ancient. SImilarly, someone doing a search for something, either from within the forum or via Google, et. al., will often return long dead threads.

Having said that, there IS the mechanism that when you reply to a thread that was last active more than a year ago, you get a big red warning box that you have to check off saying that you realize that it is an old thread and you want to reply anyway. THAT's were I find myself scratching my head on many necroposts.

 

Having said that, there IS the mechanism that when you reply to a thread that was last active more than a year ago, you get a big red warning box that you have to check off saying that you realize that it is an old thread and you want to reply anyway. THAT's were I find myself scratching my head on many necroposts.

Yes, I have a handle on all of that. I just, like you, scratch my head as to why a brand new member would dig up such an old thread when the actual subject matter was pretty well addressed and original question answered over 5 years ago? Not saying it's a bad thing, just questioning it.

Ron

 

I just, like you, scratch my head as to why a brand new member would dig up such an old thread

The member who resurrected the thread joined 5 years ago! Though he's not a very active "Active Member"...

 

Yeah, with two post I can see they are not very active.

Ron

 

Hi,

What is most interesting about this thread is that there have been over 24000 views. Is that correct?
If so, that would tell us that there are a lot of people looking for information on how to parallel batteries.
We could start a company called, "HTPB Inc.", which stands for "How To Parallel Batteries, Inc."
Because of all the problems that come up maybe a better name would be, "How Not To Parallel Batteries"

 

I'm in.

Ron

 

I'm in.

Ron

I could see this becoming the start of a funny comedy thread too because of what can go wrong when paralleling batteries. ie Circus music in the background
Maybe a new movie too: "Abbott and Costello Meet Frankenbattery".

 

Who's that guy who shocked his tongue on YouTube? Get HIM to parallel batteries and make a video of it. Now THERE's entertainment.

 

I could see this becoming the start of a funny comedy thread too because of what can go wrong when paralleling batteries. ie Circus music in the background
Maybe a new movie too: "Abbott and Costello Meet Frankenbattery".

MrAl, this is serious stuff. I knew a guy, who knew a guy, who had a sister who was engaged to a guy and his cousin tried to parallel batteries and this was the result:

Ron

 

Hi,

What is most interesting about this thread is that there have been over 24000 views. Is that correct?
If so, that would tell us that there are a lot of people looking for information on how to parallel batteries.
We could start a company called, "HTPB Inc.", which stands for "How To Parallel Batteries, Inc."
Because of all the problems that come up maybe a better name would be, "How Not To Parallel Batteries"

I'd opt for just pointing them to batteryuniversity.com. Someone recently posted that they had heartburn over something related to connecting batteries in parallel (at batteryuniversity.com), but I trust the information at batteryuniversity.com more than anything posted here.

 

I think the way to approach this question is to get out some voltmeters & ammeters; connect & measure (using precautions like making very brief connections at first). Once a nurse where I worked could not get into her car because the button battery in her car remote had died. I took her button battery & hooked it to my automobile lead-acid battery (in parallel) briefly. Nothing exploded. But the remote then worked. Evidently the button battery was recharged at least a little. Now what I propose to do is to use a 16 V lead acid battery to jump start a vehicle that has a 12 V battery & see what happens, look at the vehicle's built-in volt meter. What I have been seeing is a drop to about 8-9 volts on the existing 12 V battery when I crank. Do not alternators routinely stick over 14 volts in parallel onto 12 volt batteries with no explosions? & What voltage do you read at the battery terminals while they are connected?