Anyone for 3-Bank Battery Charger ?

[scottyb]

There is some mis information in this thread. All the batteries in a series pack receive an equal charge. They don't charge once and charge again or gas while waiting for another battery to charge UNLESS you have a serious imbalance in the pack. That is why it is so important to have a balanced pack.

Understand we are not working with rockets here scientists. These are DC electric golf carts. They are used to transport fat people over moderate ground. The battery pack is designed to give 5 years of useful service, generally. Check water levels & charge after use with the OEM charger & you will likely meet or exceed this goal.
Are there better chargers? Yes. Are there higher (or more anal) standards? Yes. Do we need to be overly concerned about them? No.
Example: My wife's 70 yr old Aunt used an old heavy 3 wheel cart to haul a horse feed wagon 2xs a day. The cart had a power robbing resistor coil speed control system and big transformer charger (25amp) She knew enough to keep the water levels up and charged once a week regardless of use. The poor batteries got improperly charged 468 times over 9 years and still had enough life left in them to drive the cart to the grave.
I spent time in the service industry. I tested random carts for battery condition daily. I found no evidence of this first cell failure. When I did see battery failure I found it was closely tied to the remainder of the pack. No one or two batteries were typically failing even as much as 25% sooner than the balance of the pack. Because in series the draw and the charge is uniform for all applicable purposes in my experience which I supported with countless hours of refractometer analysis.

If you have quantitative evidence to the contrary we would view it. Thank you for the discussion.
So enjoy your discussion. It is good to realize your batteries have certain needs & require certain considerations, however, your modern charger

P.S.
God instructed Noah how to build the Ark. Certainly you don't imply God is an armature?

[simple man]

Originally Posted by seulater

As an FYI, for the car battery. The all 6 cells in a 12v battery are subject to the same heat in the engine compartment. So heat is not the factor why the 1'st cell by the + Post typically craps out first.

I have a theory on this, from experience over the years. The + post is always the one to corrode first. I don't know why this is, but it is true for any battery! The corrosion causes a poor connection, that causes heat. Over and over again the + post gets hotter than the other cell connectors. Like I said, this is just my theory, but it seems sound! Sometimes a connection will be so bad that the post, or terminal, will melt!

[gornoman]

Originally Posted by simple man

I have a theory on this, from experience over the years. The + post is always the one to corrode first. I don't know why this is, but it is true for any battery! The corrosion causes a poor connection, that causes heat. Over and over again the + post gets hotter than the other cell connectors. Like I said, this is just my theory, but it seems sound! Sometimes a connection will be so bad that the post, or terminal, will melt!

The negative battery post on our Honda Odyssey had corrosion present just last week. Positive post was clean as a whistle.

[scottyb]

Why are 3 chargers better than 1 charger? If one charge heats up 2 end point cells then would 3 chargers heat up 6 end point cells?

Are they little chargers providing the proper algorithm the battery manufacture suggests?

[yurtle]

I promise I'm not trying to fan the flames, but I offer a possible explanation to something you apparently have seen in cell phone and RC batteries.

Is it possible that super cheap, mass produced cells, are "so" unequal that they benefit from separate charging circuits for each cell, rather than solving a perceived problem with "end" cells failing first?

[seulater]

Yikers, how did something so simple turn to strange.

@scottyb, i agree with you on the fact that the stock charger will be more than adequate for the average guy. I did say that we are all anal with some things. Proper battery charging is one of mine, Will my batteries last more than the same set used with the stock charger, yes. Will it make my batteries last another 2 years, probably not. It the anal factor. Just knowing that i am doing what is best for the batteries give me peace of mind. Not to mention a bank changer is less than the stock one. Which is why i posted this thread to start with. A guy on a low budget, could get one of these for less, and better charge their batteries.

Again, i have offered more than one way to prove these things. I have not just given smoke and mirrors. Next time you get a battery at EOL and is sort of dry inside, take the caps off it and set the charger on it on boost. you will see small amounts of smoke coming from the most + cap vent. This is yet just one more way to prove what i am talking about. The current always flows form the + to the Negative on charge.

Why are 3 chargers better than 1 charger? If one charge heats up 2 end point cells then would 3 chargers heat up 6 end point cells?

Are they little chargers providing the proper algorithm the battery manufacture suggests?

The best thing to do is to look up how a Li-Po pack charger charges a battery pack. This will hopefully explain it better than i have tried to and failed. There is a reason they make bank chargers, there is a reason that almost every boat on the sea has them.



As far as This goes.

God instructed Noah how to build the Ark. Certainly you don't imply God is an armature?

Of course not! I use this statement for people who think that just because they are taught in a high tech field they know everything. GOD gave Noah the main parameters to know on how to build it. He did not give him a blueprint for the entire vessel. So there was much of Noah's own ideas and concepts involved in it as well. Not to make Noah lifted up higher than GOD, just showing that just because one was educated with a degree does not mean they don't know anything. Much like us, as we get older we learn from things as we go along and can use them on other things.


At this point i feel like Noah, The storm is coming, the storm is coming and everyone is saying ya right your nuts.

I wish you all the best, i really do! But this thread has taken a turn far from its intended point.

[scottyb]

We see a lot of people come through here. Sometimes we get the wrong impression with our limited view and this 2D print.
It did seem you were telling us there was a better way to charge the batteries? What about the 4 additional endpoints, if in fact endpoints are trouble or weak spots.... and what is the algorithm of these chargers?

[seulater]

Originally Posted by yurtle

I promise I'm not trying to fan the flames, but I offer a possible explanation to something you apparently have seen in cell phone and RC batteries.
Is it possible that super cheap, mass produced cells, are "so" unequal that they benefit from separate charging circuits for each cell, rather than solving a perceived problem with "end" cells failing first?

I dont mind honest questions, and will always try to answer as best i can. I am the type of person that i will NEVER offer any answer or opinion that i have no personal experience with.

I should make note, here while i think about it that EVERYTHING i have said applies to a fast charge not a trickle or slow 1-2A charge. A high current charge is when you heat up the end most + cell. a slow charge does not affect it to the point where its even a problem.


I hope this does not get to long and boring. But it basically goes like this.
Years and years ago when Ni Cad was the best we had. It was known that the + most end cell got the hottest during a fast charge. Even get so hot it would vent. Ask anyone in the RC business who was into racing. I guarantee you if they are worth their salt they will tell you the same thing. I was into racing RC speed boats. Many times pushing a pack to over 140A. Over 15 years ago i though that it would be better to have a second plug on a battery pack which all the wires went to each cell. So the charger could charge them individually. EVERYONE in ever told this to back then even my best friends though it was nuts. Telling me who would ever need or want to charge a battery that way. In my ignorance and youth i let them convince me it was a bad idea. Yet look at EVERY charger from every manuf. on the market today for charging these Li-po today. They are all exactly what i suggested back then. Had i stuck to my guns and not let the people who did not see the light yet talk me out of it i would be in a whole other place today.

I digress, sorry i would have to say that there are so many cheap cells out there that they are un balanced when placed into a pack. But that is the beauty of it, it does not matter if they are made so cheap they are un balanced. The charger takes care of it with its multiple lead output to each cell. Even if you were to make a matched pack, which we did just that back in the day of racing boats, they would only stay matched for a few charge / discharge cycles. Believe it or not once a month a few of us would buy 200 cells, and charge and discharge each cell individually. the high end charger we had would give a readout of starting voltage, end voltage and ma charged into the battery. then it would discharge them at a high rate and give results for that cell. we would record this for all these cells and in the end put only those cells that were the closest match together in a 8-cell pack. All batteries has this same phenomenon, when they charge as far as the outer most + cell taking the brunt when high amperage charging.

[seulater]

Originally Posted by scottyb

We see a lot of people come through here. Sometimes we get the wrong impression with our limited view and this 2D print.
It did seem you were telling us there was a better way to charge the batteries? What about the 4 additional endpoints, if in fact endpoints are trouble or weak spots.... and what is the algorithm of these chargers?

You make a good point i guess i have to make my bones first huh ;)

what drawing are you referring to, end points are not the trouble, its a single battery in the in the pack getting up to charge first when the others are not.

"and what is the algorithm of these chargers?" Please read what i have to say carefully. Before trying this, not all charges are created equal, or for that matter even designed correctly. You don't have to get a "bank" charger to do what i am explaining here. You could just as easily grab 3 - 12v chargers from walmart and do the same thing. The only problem from trying this with a so called walmart charger is did the designers make it a floating output. If not then this will not work. It MUST be a floating output. Bank chargers have floating outputs so when you connect the + lead of bank one with the - lead of bank 2 together they dont buck heads with each other. Its not that there is a special charging algorithm that makes these bank charges great, its their ability to charge each battery separate from the rest. It like filling a cup, when it full stop, and fill the rest. dont try to fill them all at once, some will be overfull and the rest will not have enough.

[yurtle]

I get everything you're saying, but still don't get the "end" cell phenomenon.

Comparing a series electrical circuit with a blow torch or a sledge hammer just doesn't seem to fit.

Sorry if I've taken your post in places you didn't want it to go, but I think we need to understand statements, such as, "Its a well known fact that charging batteries in series that the end battery takes the hardest hit", since this forum is meant to be informative.

I can't tell you how many of us have heard folks say that you need to drive your pack until it's nearly dead, at least a couple of times a month. Continuing that myth does a disservice to newbies.