| What does Battery Chemistry matter to me? |
There are many different chemistries for batteries, each having different facets including:
There are other differences, too, like what temperature range a chemistry will work well within and how quickly a cell will discharge in storage. But the main differences are listed above so that is all we will consider at this time.
The obvious question is - Why don't we just use the best chemistry?
It's because the differing chemistries have tradeoffs in the main factors listed. There is no best one, just the best one for a particular application.
Non-rechargeable Batteries
Generally, non-rechargeable batteries have greater capacities than their rechargeable counterparts. They also generally stay charged in storage better.
For example; An alkaline AA battery will have a rated capacity of about the same as a single charge of a NiMH AA battery, but the alkaline battery has a higher voltage, meaning overall it delivers more energy.
In a typical lower-current application like a small radio, the alkaline batteries should last you about 30% longer than a NiMH AA in the same place. And if the radio isn't used much, the better storage life of the alkaline cells make them easier to work with, not to mention pennies compared to dollars in initial costs.
Non-rechargeable lithium has some amazing specific energy and energy density. That's why when capacity is the most important factor, non-rechargeable lithium is king when recharging is not a practical option.
Why is recharging a battery not always a practical option?
Rechargeable batteries would be great to use all the time because the electricity for a recharge is very little money compared to buying a whole new battery. But there are other costs - The cost of replacing the battery more often, and up-front costs that are much higher than non-rechargeable counterparts. And there is more management involved with switching out discharged batteries with charged replacements.
So why don't we use the best of each type; rechargeable and non-rechargeable?
Because trade-offs are made with every type of battery chemistry. Which, unfortunately, means we have to pay attention to the different properties of each type. Still, the first difference we note is between non-rechargeable and rechargeable.
As far as non-rechargeables go
Alkaline is inexpensive, although it doesn't store as well or deliver current as well as some other chemistries. Lithium is expensive and doesn't deliver current as well as some other chemistries (although lithium's higher voltage makes up for this somewhat). Then there is 1.5V lithium, which is a monopoly product by Energizer that is a special case in its own right. There are a few more non-rechargeable chemistries that have niche markets and I'll probably go over them in a future post. Still, when a company designs a product, they generally have to decide on either alkaline or lithium because alkaline is about 1/2 the voltage of lithium. To make it for both, such different voltages would drive up the cost.
As far as rechargeables go
This could be a topic unto itself. Because the nature of recharging is so attractive designers would like to use it if they can. And a lot of chemical engineers have thought of a lot of different cell types to address problems by designers. But they haven't found a chemistry that will address all problems. Thus, designers use rechargeable chemistries based on cell factors are most important to their design.
Some specs on the main chemistries
Here is a list of chemistries and their capacity per weight and volume. There are many sub-chemistries and varying constructions used to make the above cells, so these numbers are a general rule-of-thumb comparison:
(Watt-hours per kg / Watt-hours per liter) Lead acid 40/100 Alkaline 110/320 Non-rechargeable lithium 700/1100 Silver oxide 130/500 NiMH 90/250 Lithium-ion 150/330 LiFePO4 105/210 |
Thursday, March 30, 2017
What can chemistry do for me?
This article appeared at Zbattery.com some time ago. I see it needs some updating so I'll reprint it with edits here:
Wednesday, February 22, 2017
Under Pressure!
This article was published after a number of people were coming in to replace bloated batteries. This situation didn't look safe and they wondered what happened.
This battery has been catastrophically overcharged. We recommend unplugging the charger from the wall before unhooking the battery’s terminals. The battery may contain volatile gasses that could react badly to a spark near the battery’s vent. When a battery is charged it creates gasses that re-combine into solution; however, when the charge creates gasses faster than they can re-combine, that gas creates pressure inside the battery.
What happened to my battery?!
This battery has been catastrophically overcharged. We recommend unplugging the charger from the wall before unhooking the battery’s terminals. The battery may contain volatile gasses that could react badly to a spark near the battery’s vent. When a battery is charged it creates gasses that re-combine into solution; however, when the charge creates gasses faster than they can re-combine, that gas creates pressure inside the battery.
So what happened to the battery in the picture? Typically, a battery’s vents will expel any gas pressure that builds up faster than the gas can re-combine. The battery pictured above, however, collected gasses faster than the vents could remove them, allowing pressure to build up internally. Luckily for the customer, the additional safety features in the battery limited the damage to the battery only—sparing the charger and the charging environment. The malleable plastic design of this sealed lead acid battery allowed it to balloon without breaking, and an internal shorting design ceased the collection of more gasses. Furthermore, these batteries are designed with the electrolyte, an acid, to be absorbed in a glass mat, preventing the spilling of acid even in the instance of a broken casing. Our best guess is that a large 12V charger was used on this relatively small 6V battery.
How can you prevent overcharging your battery?
The most common overcharging error we see is matching a battery to a charger that is not designed for use with that battery’s capacity even if the voltage is the same. For instance, our 12 volt 3 Amp charger should not, in general, be used on 12 volt batteries that have a capacity below 10Ah. A capacity miss-match will result in a charge that may be harder on a battery than it should be, shortening the battery’s life. As batteries are used, their chemical properties degrade. They will hold less and less energy as time goes by, meaning their capacity decreases over time. If a battery degrades to a level below the range a charger was designed for, the charger may begin to overcharge that battery. In that case, the battery will wear out faster and faster each time it is charged. Of course, if a charger was designed for higher voltage batteries, hooking up a lower voltage battery will overcharge that battery.
Chargers are often engineered with built-in overcharge protection; they charge in stages, stopping or reducing the energy going into the battery when it is full. Yet there are some models that are not designed to stop charging after a battery is full which will shorten the life of the battery, sometimes severely. This will often cause customers to believe they have a defective battery rather than a defective charger and they end up overcharging battery after battery.
These instances will rarely result in the kind of swelling you see in the photo, but it will shorten the life of your battery or render the battery unusable.
So pay attention to the charger you use on a battery. Don’t use a car charger with small sealed lead acid batteries (or, in general, any batteries that use a glass mat to absorb the electrolyte). If you aren’t sure a charger is slowing down its charge after a battery is full, take the battery off the charger when it’s fully charged. A rule of thumb is to not leave a battery on a charger that you are sure will charge the battery in about 10 hours. And last, but not least, pay attention to the voltage the charger was designed for and the voltage of the battery you are charging.
Tuesday, February 7, 2017
What's on the bench
A number of people have asked what is on the test bench at Zbattery.
The simple answer is 1 battery analyzer and 3 variable power supplies.
That is what is used the most. The variable power supplies charge the batteries, which can be monitored by the analyzer if needed. And the analyzer also records any discharge.
The analyzer can handle 48V, or 150W, or 40A. That's not too bad in most cases. Sometimes with very large or very small batteries, we have to either split the supply or amplify it. That makes a test less accurate, but it doesn't happen often and the result is usually close enough.
The analyzer is really the center of the test bench.
And we've found the best chargers are the variable power supplies for these reasons.
It's not to say we don't have smart chargers. We have them for some more common cells/packs. Also, we sometimes need to charge something faster than a variable power supply method will allow which a smart charger does.
Testing is something we love doing. One of the most popular articles is about testing AA alkaline batteries. Who doesn't want to know what the best AA alkaline battery is? Although that set of tests is getting rather old because the latest in alkaline battery technology is a little better than they show. I'll work to update that information and I'll republish the old article here as well.
If there is any question about battery testing, or if there is a specific test you haven't seen, just let me know.
The simple answer is 1 battery analyzer and 3 variable power supplies.
That is what is used the most. The variable power supplies charge the batteries, which can be monitored by the analyzer if needed. And the analyzer also records any discharge.
The analyzer can handle 48V, or 150W, or 40A. That's not too bad in most cases. Sometimes with very large or very small batteries, we have to either split the supply or amplify it. That makes a test less accurate, but it doesn't happen often and the result is usually close enough.
The analyzer is really the center of the test bench.
And we've found the best chargers are the variable power supplies for these reasons.
- They are accurate to a hundredth of a volt and charge almost any cell and pack.
- Variable smart chargers are limited to a range of batteries and packs and we'd need other smart chargers to do as wide a range as the power supplies do.
- We can "rig" up a charging protocol with power supplies if a pack/cell falls outside the immediate range of what they can do natively while smart chargers can only do their native range of cells/packs.
- And sometimes we want to know exactly what the charger is doing - voltage and amperage wise - which only the most expensive of variable chargers will let us do.
It's not to say we don't have smart chargers. We have them for some more common cells/packs. Also, we sometimes need to charge something faster than a variable power supply method will allow which a smart charger does.
Testing is something we love doing. One of the most popular articles is about testing AA alkaline batteries. Who doesn't want to know what the best AA alkaline battery is? Although that set of tests is getting rather old because the latest in alkaline battery technology is a little better than they show. I'll work to update that information and I'll republish the old article here as well.
If there is any question about battery testing, or if there is a specific test you haven't seen, just let me know.
Wednesday, February 1, 2017
EZ Battery Reconditioning Guide Exposed
Someone was nice enough to tell us what they learned from a part of the EZ Battery Reconditioning guide. Sure, the EZ Battery people got their money, but at least we can give the person that asked an honest opinion on what they bought.
One of the supplementary guides is titled "How To Revive A Dead Phone Battery", and I made sure to ask if the word Dead was in quotes. There is supposedly more information on how to recondition li-ion batteries beyond the supplement. But we'll start with the supplement.
The word Dead is not in quotes. They supposedly put it in quotes later in the document.
Wow... If I had the chutzpah to pull off publishing something like this for money I'd probably be richer in my bank account. Fortunately, I value my soul more than my bank account.
The method they propose is to "jump start" a good battery that has gone below what we call the "threshold voltage".
I'll explain what a threshold voltage is. Every cell phone has a charger in it that takes a 5V USB signal and modifies it to properly charge the li-ion battery. If the voltage of the battery goes below a certain level (the threshold voltage) the electronics in the phone will not recognize the battery and thus won't charge it. The solution COULD be to raise the voltage of the cell just a little so it reaches the threshold voltage and the phone can recognize the battery and charge it. This, again, only works if the battery is actually a good battery that happens to have a low voltage.
Please note, every smart charger has a threshold voltage regardless of chemistry the charger works with. The solution in cases like this, whether it be Lead Acid, NiCd, NiMH, or even Li-Ion is to charge the battery with what we call a "dumb" charger. A dumb charger is just a power supply that delivers a certain voltage whenever electrically possible and thus a threshold voltage is not applicable.
That power supply could be any DC power source in a certain voltage range above the threshold voltage. Even another battery of the same type that has enough charge in it to give a low battery a higher voltage would work.
So the guide says that to revive a DEAD PHONE BATTERY one should apply a straight 5VDC from a USB supply by cutting a USB cable, expose the bare leads, and touch them to the + and - of the battery in the right order.
Doing that CAN raise the voltage of a single cell li-ion battery enough for the charger to start working. Don't hold it on the battery too long, though, because the battery will be taking in the full Amperage that the USB supply will deliver. And it will take that Amperage for as long as the wires are touching the contacts - even after the battery is fully charged. And overcharging a li-ion battery is a bad idea. As far as I understand, the supplemental guide does not give a time limit, but I wouldn't want to hold those wires on there for more than a few seconds. If this trick is going to work, that's all the time it should need.
But is that the kind of dead phone battery that 99.999% of us run into? The kind of battery that is good but just happens to be below the threshold voltage of the phone? No. The dead phone batteries we encounter are ones that have been in use for a year or three and need to be charged at lunch just to make it through the day.
This EZ Battery Reconditioning trick won't work for a battery like that.
I realize the title of the guide and the supplement and all their advertising might lead you to believe that a normal dead battery that you get after using your phone for 3 years can be reconditioned. And perhaps there are other parts of the guide that go into that. But nothing about it has been told to me yet.
Perhaps people can ask me more questions about the methods in the guides and I'll keep giving my opinion on their effectiveness.
Do you have a EZ Battery Reconditioning guide? Have a question about it? Feel free to ask in the comments!
One of the supplementary guides is titled "How To Revive A Dead Phone Battery", and I made sure to ask if the word Dead was in quotes. There is supposedly more information on how to recondition li-ion batteries beyond the supplement. But we'll start with the supplement.
The word Dead is not in quotes. They supposedly put it in quotes later in the document.
Wow... If I had the chutzpah to pull off publishing something like this for money I'd probably be richer in my bank account. Fortunately, I value my soul more than my bank account.
The method they propose is to "jump start" a good battery that has gone below what we call the "threshold voltage".
I'll explain what a threshold voltage is. Every cell phone has a charger in it that takes a 5V USB signal and modifies it to properly charge the li-ion battery. If the voltage of the battery goes below a certain level (the threshold voltage) the electronics in the phone will not recognize the battery and thus won't charge it. The solution COULD be to raise the voltage of the cell just a little so it reaches the threshold voltage and the phone can recognize the battery and charge it. This, again, only works if the battery is actually a good battery that happens to have a low voltage.
Please note, every smart charger has a threshold voltage regardless of chemistry the charger works with. The solution in cases like this, whether it be Lead Acid, NiCd, NiMH, or even Li-Ion is to charge the battery with what we call a "dumb" charger. A dumb charger is just a power supply that delivers a certain voltage whenever electrically possible and thus a threshold voltage is not applicable.
That power supply could be any DC power source in a certain voltage range above the threshold voltage. Even another battery of the same type that has enough charge in it to give a low battery a higher voltage would work.
So the guide says that to revive a DEAD PHONE BATTERY one should apply a straight 5VDC from a USB supply by cutting a USB cable, expose the bare leads, and touch them to the + and - of the battery in the right order.
Doing that CAN raise the voltage of a single cell li-ion battery enough for the charger to start working. Don't hold it on the battery too long, though, because the battery will be taking in the full Amperage that the USB supply will deliver. And it will take that Amperage for as long as the wires are touching the contacts - even after the battery is fully charged. And overcharging a li-ion battery is a bad idea. As far as I understand, the supplemental guide does not give a time limit, but I wouldn't want to hold those wires on there for more than a few seconds. If this trick is going to work, that's all the time it should need.
But is that the kind of dead phone battery that 99.999% of us run into? The kind of battery that is good but just happens to be below the threshold voltage of the phone? No. The dead phone batteries we encounter are ones that have been in use for a year or three and need to be charged at lunch just to make it through the day.
This EZ Battery Reconditioning trick won't work for a battery like that.
I realize the title of the guide and the supplement and all their advertising might lead you to believe that a normal dead battery that you get after using your phone for 3 years can be reconditioned. And perhaps there are other parts of the guide that go into that. But nothing about it has been told to me yet.
Perhaps people can ask me more questions about the methods in the guides and I'll keep giving my opinion on their effectiveness.
Do you have a EZ Battery Reconditioning guide? Have a question about it? Feel free to ask in the comments!
Thursday, January 26, 2017
More on EZ Battery Reconditioning
What they don't imply
One thing to note about EZ Battery Reconditioning. You won't find the claim to be "how to find good batteries that people throw away. I'm sure that wouldn't sell as well.
A claim like:
is a great deal more enticing because getting good batteries that people throw away is a lot harder than getting dead batteries that people throw away.
But I'm going to guess, without having read the book, that a lot of the secret is to get batteries that people don't want anymore and check to see if they are really no good or if they can still be used.
What I think they might suggest
With a simple voltmeter, one can check a non-rechargeable battery. That's how the battery testers do it. If an alkaline battery is over 1.5V, it's probably good. If a non-rechargeable lithium battery is over 3.0V, it's probably good. If a silver oxide battery is over 1.55V, it probably has enough life left to be considered good.
But NONE of that is "bringing dead batteries back to life.
One might even check a battery to see if it is good "under load", which is a better test. But how much load should one put on a non-rechargeable battery for how long for it to be considered good? I could go into that because it isn't that complicated, but it's not dead simple. It will be a good topic for a future post.
But back to our EZ Battery Reconditioning people.
What they do imply
They imply that dead rechargeable batteries can be brought back to life. Non-rechargeable batteries can only be brought back to life under certain conditions, but we've found that even under the best conditions it still isn't worth it. What I mean is that alkaline batteries CAN be recharged, but they are much weaker after it is done, and they don't recharge enough times to go to the trouble.
Please note: they use the words "Long Life" and "Alkaline" on their website. Here's the screenshot:
And they use the word "Recondition" to top it all off. So if they mean there are chargers to recharge alkaline batteries, well, I suppose you might still be able to find one. But "long life" batteries are more commonly known as carbon zinc or zinc chloride. And these cannot be reconditioned. Again, though, there is a little wiggle room with the terminology seeing as someone could always say that "long life" just means any battery should have a good long life.
What I really think is inside the alleged "guide"
They probably tell you about a few tricks that are no secret in the battery industry. We've tried these before with RARE success. Here is the list:
One thing to note about EZ Battery Reconditioning. You won't find the claim to be "how to find good batteries that people throw away. I'm sure that wouldn't sell as well.
A claim like:
"Bringing Dead Batteries Back To Life Is Simple!"
is a great deal more enticing because getting good batteries that people throw away is a lot harder than getting dead batteries that people throw away.
But I'm going to guess, without having read the book, that a lot of the secret is to get batteries that people don't want anymore and check to see if they are really no good or if they can still be used.
What I think they might suggest
With a simple voltmeter, one can check a non-rechargeable battery. That's how the battery testers do it. If an alkaline battery is over 1.5V, it's probably good. If a non-rechargeable lithium battery is over 3.0V, it's probably good. If a silver oxide battery is over 1.55V, it probably has enough life left to be considered good.
But NONE of that is "bringing dead batteries back to life.
One might even check a battery to see if it is good "under load", which is a better test. But how much load should one put on a non-rechargeable battery for how long for it to be considered good? I could go into that because it isn't that complicated, but it's not dead simple. It will be a good topic for a future post.
But back to our EZ Battery Reconditioning people.
What they do imply
They imply that dead rechargeable batteries can be brought back to life. Non-rechargeable batteries can only be brought back to life under certain conditions, but we've found that even under the best conditions it still isn't worth it. What I mean is that alkaline batteries CAN be recharged, but they are much weaker after it is done, and they don't recharge enough times to go to the trouble.
Please note: they use the words "Long Life" and "Alkaline" on their website. Here's the screenshot:
And they use the word "Recondition" to top it all off. So if they mean there are chargers to recharge alkaline batteries, well, I suppose you might still be able to find one. But "long life" batteries are more commonly known as carbon zinc or zinc chloride. And these cannot be reconditioned. Again, though, there is a little wiggle room with the terminology seeing as someone could always say that "long life" just means any battery should have a good long life.
What I really think is inside the alleged "guide"
They probably tell you about a few tricks that are no secret in the battery industry. We've tried these before with RARE success. Here is the list:
- For lead acid batteries, add some Epsom salt to de-sulfate the plates
- For NiCd batteries, a cell can be "zapped" with 10x voltage to burn off any internal shorts
- For NiCd batteries again, if they have life but one wants to try and revive them to a better life; cycle them a few times with a deep discharge to about .2V per cell
Tentative Conclusion
I doubt it.
They claim in their video that "any" battery can be reconditioned. They claim in thier screenshot that lithium batteries, which are what laptop batteries are, can be reconditioned. They claim NiMH batteries can be reconditioned in their list, as well.
I don't think it's possible.
They claim in their video that "any" battery can be reconditioned. They claim in thier screenshot that lithium batteries, which are what laptop batteries are, can be reconditioned. They claim NiMH batteries can be reconditioned in their list, as well.
I don't think it's possible.
I'm going to look into it further, but I don't think my conclusion will be proved wrong.
Tuesday, January 24, 2017
How do they get away with it?
So I was looking at this battery reconditioning site. They sell an e-book that supposedly tells people how to restore their spent batteries to "100% of their working condition."
There might be a little wiggle room in there that "working condition" is not "new condition." However, they do claim that batteries using this guide will be in "new" condition in the video.
I began to look on the web to find people that had tried the guide and reviewed it. But there was no-one. I'm sure people will point to all the review sites listed for this process, but they are all sites that also get money if the guide sells from that site. They are all thinly veiled sales sites at best, and have nothing to do with reviewing the product.
So how are they doing it? How do they make such bold claims that would certainly be worth the $27-$47 it is selling for on various sites and yet no independent party has reviewed the claims?
I'll keep looking at this and write more about it as I find out more.
But just to give you an idea of the claims, take a look at these:
I'm looking at links and videos, and perhaps I'll even give them some money just to make an honest review of my own.
There might be a little wiggle room in there that "working condition" is not "new condition." However, they do claim that batteries using this guide will be in "new" condition in the video.
I began to look on the web to find people that had tried the guide and reviewed it. But there was no-one. I'm sure people will point to all the review sites listed for this process, but they are all sites that also get money if the guide sells from that site. They are all thinly veiled sales sites at best, and have nothing to do with reviewing the product.
So how are they doing it? How do they make such bold claims that would certainly be worth the $27-$47 it is selling for on various sites and yet no independent party has reviewed the claims?
I'll keep looking at this and write more about it as I find out more.
But just to give you an idea of the claims, take a look at these:
The EZ Battery Reconditioning™ course is the easy to follow, step-by-step system anyone can use to recondition all kinds of old or dead batteries with just simple supplies you probably already have in your home.
The course is made up of step-by-step guides that show you how to recondition each type of battery. And each guide is full of pictures and diagrams so you not only read exactly what to do …you see exactly what to do as well!
It’s like having me and Frank (aka "The Battery Man") standing there with you, guiding you every step of the way as you recondition your batteries.
And it doesn’t matter if you’re not technical or don’t know the first thing about batteries …because our course is incredibly easy to follow and absolutely anybody can use it.
I'm looking at links and videos, and perhaps I'll even give them some money just to make an honest review of my own.
Friday, January 20, 2017
VRLA Battery Guide
Zbattery published this very nice information on VRLA batteries. Take time to comment on the guide and we'll update it with the latest information.
Valve Regulated Lead Acid (VRLA) Batteries are low maintenance sealed lead-acid batteries. They limit inflow and outflow of gas to the cell – thus the term “valve regulated”. VRLA batteries are unique due to the fact that they contain a “starved” electrolyte (acid), which is absorbed or immobilized in a separator.
Electrolytes are commonly absorbed or immobilized in two ways:
Absorbed electrolyte: a highly porous mat made from microglass fibers is partially filled with electrolyte, acting as a separator. Also called AGM for Absorbed Glass Mat.
Gelled electrolyte: Fumed silica is hardened into a gel that free-floats in its container. During charges, the gel dries more creating cracks and fissures develop between the positive and negative. Often referred to as Gel Cell.
Advantages:
· Maintenance-free
· Moderate Life
· High-rate capacity
· High charge efficiency
· No “memory effect”
· State of charge can be determined by measuring voltage
· Relatively low cost
· Available in a variety of sizes and voltages from single cell units (2V) to 48V or higher
Disadvantages
· Cannot be stored in discharged condition
· Relatively low-energy density
· Lower cycle than NiCad batteries
· Thermal runaway can occur with incorrect charging or improper thermal management
· More sensitive to temperatures than conventional lead-acid batteries
According to BatteryUniversity.com, “heat reduces the life of VRLA. Most batteries are enclosed in spaces without proper ventilation or cooling. Every 8°C (15°F) rise in temperature cuts the battery life in half. A VRLA battery, which would last for 10 years at 25°C (77°F), will only be good for 5 years if operated at 33°C (95°F). Once damaged by heat, no remedy exists to improve capacity.”
Simple Guidelines
· Always store in a charged condition. Never allow the open cell voltage to drop below 2.10V. Apply a topping charge every six months or when recommended.
· Avoid repeated deep discharges. Charge more often.
· Prevent sulfation and grid corrosion by choosing the correct charge and float voltages. If possible, allow a fully saturated charge of 14h.
· To reverse sulfation, raise the charge voltage above 2.4V per cell for a few hours.
· Avoid operating lead-acid at elevated ambient temperatures.
VRLA Uses:
· Fork Lifts
· Uninterruptible Power Supplies
· Emergency Lighting
· Wheelchairs
· Telecom Back-Up Power Supplies
· Lawn and Garden Tools
· Engine Starters
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