Simplified & Practical Lithium Charging?

[warrior 90]

Originally Posted by SV THIRD DAY

Do you mind if I ask what's the point?
Isn't the simicity of charging the 4 cells with a single simple programable battery charger the easy way to go when the batteries are wired in series?

100% agreed....this is no rocket science
but to comply with battery manufacturers and to get long life from the batteries let´s put an EL CHEAPO to monitor balance

https://electriccarpartscompany.3dca...ower%20BMS.pdf

[Cadence]

Originally Posted by SV THIRD DAY

Set you solar controller, battery charger, wind generator controller, alternator regulatoe, hydrogen, and hampster wheel to let's say...13.4v to 13.6v and done. No drama, no over charge risk, simple and easy. Then move on and enjoy life. Its been working great for my 400ah bank now for 7 months. This ain't rocket science science folks, stop trying to make it harder than it is.

"Ain't" no fun if you can't put out formulas to prove you are a rocket scientist.

[hellosailor]

Many companies (especially car makers) won't release their research because it is a justifiable real trade secret. If Toyota can get 100k miles out of a $10,000 battery pack but Ford gets 50% more mileage out of it, which car are you going to buy? Ahuh, right, the one with less shrapnel in the air bags but I mean, after you ignore that.


BMSes are not necessarily cheap--that depends on how complicated they are! And frankly, if you've got a $1000 battery and you can "replace" the thousand dollar BMS with $200 worth of bigger cells...that's a no-brainer, unless you planned to use that BMS for 60-odd years. (At least one supplier was suggesting a "mandatory" BMS that really did cost that much, just a few years ago.)


As to whether a charge cycle from 20-90%, or 30-80%, or whatever is advisable? I think that's called "Here's the voltage adjust knobs, knock yourself out." The point can be made that for a Pacific crossing, you'd want 100% capacity, but if you were lazing around in Baja for three weeks waiting for a weather window, you might want to change that to 70% capacity until the day before you head out.


That's one advantage to kicking the pea-brained silicon fascists out of our lives. And gear.


Greg-
Tesla's solution may in fact have more to do with "How do we justify a billion dollar megabattery factory?" than anything practical to the rest of us. If I'm not mistaken, they still lose money every quarter and without tax subsidies, they'd lose even more market as well. Scaling up battery production to reduce the price, nice idea if it works. Check out how many times how many thousands of men and millions of dollars were lost on aborted "Panama Canal" projects before that finally happened. Or how many times the tunnel from England to France was planned before that got done.
Musk thinks he's going to build a battery roughly the size of an old fashioned steam radiator--something so annoying and obtrusive that they've been obsolete for fifty years--and convince people to hang them on their living room walls. Like another big flat panel tv, except eight inches thick with no picture. And then in theory, this easily affordable (ha) elephant in the room would store up utility power at night when the rates and demand are lower, or rooftop power when the sun is up and no one is home, and then release it when you need it, when loads are high or the grid is overloaded, etcetera.
And somehow this will be SO tasty, everyone will drink the KoolAide.


Well, lots of folks bought a Keurig and paid 10x what coffee costs in a tin can, so maybe he's on to something there. If he gets it down to an inch thick with a wireless Netflix connection and a 4K display...sure, I'll take another look.(G)


I give him great credit for some things, but wonder if he's heard about why fish don't buy bicycles very often?

[a64pilot]

The Prius, at least the non plug in model was NIMH batteries, not Lithium, I believe at least initially they were afraid of LIPO.
Older cell phone batteries etc with memory may have been either NIMH or Ni-Cd.

I'm not sure how useful Hybrid car battery data would be, I believe they are designed for multiple charge / discharge cycles per hour and high charge / discharge rates, unlike a house bank.
Gotta think a Prius can discharge it's battery in a couple of minutes and re-charge it in a few minutes too.

[Cadence]

Originally Posted by a64pilot

The Prius, at least the non plug in model was NIMH batteries, not Lithium, I believe at least initially they were afraid of LIPO.
Older cell phone batteries etc with memory may have been either NIMH or Ni-Cd.

I'm not sure how useful Hybrid car battery data would be, I believe they are designed for multiple charge / discharge cycles per hour and high charge / discharge rates, unlike a house bank.
Gotta think a Prius can discharge it's battery in a couple of minutes and re-charge it in a few minutes too.

I don't think I understand the new battery technology. You make a valid point. The commuter car is designed to go to work, come home and be recharged. Not really applicable to a boat with a slow drain and a slow charge, e.g. solar. Maybe some 8Ds for ballast. Can be bought cheap last forever and can be charged with a charger bought at Walmart or off the engine without something elaborate.

[nimblemotors]

Originally Posted by SV THIRD DAY

Do you mind if I ask what's the point?
Isn't the simicity of charging the 4 cells with a single simple programable battery charger the easy way to go when the batteries are wired in series?

Yes it is simpler to use a single charger for the series voltage and charge them all together in series.

There are a few points of charging the cells individually.

Biggest one is the charging source can be anything, and doesn't need to be 'programmable'. While many sources have adjustable output voltages, some don't. With this charger, it can take anything from 9v to 48v input, and it will charge the lithium cells correctly. This is a 'install it and forget it' setup, no worry about how to setup your solar/genset/wind/alt/etc for lithium.

No separate BMS to monitor cell voltages, charger does it.

The cells don't have to match at all, so one can replace 200ah cell with a 100ah cell, or have bad cells along with good cells.

And finally, charger can run in reverse and output 12v from a single cell.
Let that sink in...

[Stumble]

Originally Posted by hellosailor

Many companies (especially car makers) won't release their research because it is a justifiable real trade secret.


Greg-
Tesla's solution may in fact have more to do with "How do we justify a billion dollar megabattery factory?" than anything practical to the rest of us. If I'm not mistaken, they still lose money every quarter and without tax subsidies, they'd lose even more market as well. Scaling up battery production to reduce the price, nice idea if it works. Check out how many times how many thousands of men and millions of dollars were lost on aborted "Panama Canal" projects before that finally happened. Or how many times the tunnel from England to France was planned before that got done.
Musk thinks he's going to build a battery roughly the size of an old fashioned steam radiator--something so annoying and obtrusive that they've been obsolete for fifty years--and convince people to hang them on their living room walls. Like another big flat panel tv, except eight inches thick with no picture. And then in theory, this easily affordable (ha) elephant in the room would store up utility power at night when the rates and demand are lower, or rooftop power when the sun is up and no one is home, and then release it when you need it, when loads are high or the grid is overloaded, etcetera.
And somehow this will be SO tasty, everyone will drink the KoolAide.


Well, lots of folks bought a Keurig and paid 10x what coffee costs in a tin can, so maybe he's on to something there. If he gets it down to an inch thick with a wireless Netflix connection and a 4K display...sure, I'll take another look.(G)


I give him great credit for some things, but wonder if he's heard about why fish don't buy bicycles very often?

1) Tesla Motors released all their patents and technology on their battery systems about a year ago.

2) Don't believe that a company that isn't making money isn't really making money. Amazon hasnt made any money either, but they have quickly become a massive company. This occurs because the companies roll revenu back into infastructure instead of share dividends.

3) I am not sure I care about having a battery bank in my house, but then I pay the same flat rate for power regardless of when I use it. In an increasingly large part of the country power rates depend on when you use that power. Recharge the batteries at night on cheap power, and use it during the day when power is more expensive. Wether it is financially justified depends on the cost of the batteries and the relative savings on power. If the price of batteries comes down low enough it very well may be worth it.

3b) on a boat however a drop in Lifepo bank may be worth it now. If it was plug and play I can thing of a lot of boats that would switch just for the weight savings and increased capacity by volume. Right now lifepo is pretty close to FLA cost on a per watt usable basis, but they are too complicated for a lot of us to use. Drop the price for lifepo by 30% and make gem plug and play and you will make a fortune.

[zboss]

Elon Musk Thought Tesla Would Fail - Business Insider

[hellosailor]

Greg-
"1) Tesla Motors released all their patents and technology on their battery systems about a year ago. "
Yeah, actually mid-June not yet a year. And IIRC the statements from then, it wasn't quite that simple and comprehensive. But even if you think the patents are critical...For instance, who else will actually put up a billion bucks for a gigabattery factory?
Have you seen anybody using those patents and building Tesla clones yet? Or charging networks or battery swap stations that are interchangeable? Let the eggs hatch before we count the chickens.

"2) Don't believe that a company that isn't making money isn't really making money. ...infastructure instead of share dividends. " I do know that Musk and Tesla came within a hair of bankruptcy. And while profits can be skimmed and hidden in many ways (as in the recording industry and Hollywood) obviously somebody is getting the money that Tesla charges for cars. The question is, whether that will be a Ponzi scheme on the stockholders, who really have fronted the bill. Last time I heard numbers, 95% of all stockholders lost money and only 5% made a profit, and yet the markets have remained in business for how may decades now?

"3) I am not sure I care about having a battery bank in my house, but ...If the price of batteries comes down low enough it very well may be worth it. "
A solution in search of a problem. Why should the batteries, and the installations, be redundantly installed in a hundred million homes? Or ten thousand homes, since the millions aren't going to pay for electricians to install them, even if the electrical codes allow it.
Like I said, no one has asked for a clunky box like a radiator to be installed on their wall in a long time.

"3b) on a boat however a drop in Lifepo bank may be worth it now. "
Ah, well. Based on the # of charge cycles at 100% discharge, apparently Li batteries already ARE significantly cheaper. The problem being that you need the support system which will not damage them prematurely, and the electrical system on most mass-market boats is simply taken from cars. Which means it is NOT a deep-cycle system, and it does kill batteries, even lead-acid ones. That typically get replaced every 3-4 years by the mass market, when some folks (like Rolls) say that 8-10 years should be an easy goal.
Tesla's batteries won't help boats. They're too big for mass market, at least as proposed so far, and they don't touch the problem of off-grid CHARGING. They're aimed at on-grid storage and demand-shifting. Adaptable, perhaps, but different and not relevant compared to what could more easily be done now.
If the gigabattery factory comes online, if it doesn't bankrupt Tesla (didn't Panasonic pull out of the deal before groundbreaking?), sure, it might make Li even cheaper and more effective. That doesn't matter if it is already the most effective solution--and the claims are already stacking up to support that.
Tesla? About as relevant to boat power right now, as SpaceX is. And the hyperloop.

[warrior 90]

3b) on a boat however a drop in Lifepo bank may be worth it now. If it was plug and play I can thing of a lot of boats that would switch just for the weight savings and increased capacity by volume. Right now lifepo is pretty close to FLA cost on a per watt usable basis, but they are too complicated for a lot of us to use. Drop the price for lifepo by 30% and make gem plug and play and you will make a fortune.[/QUOTE]

It´s ALLMOST a plug and play if we keep to the subject of the title and keep it short and simple. To take out the confusion let´s keep this short, precise and easy to understand.
Lot´s of people are not into reading large storys or just don´t have the time.

For Lithium batteries more than for Lead Acid it is important to keep the voltage with in the upper and lower voltage limits recomanded in the spec sheet of the manufacturer.
This requieres a little cheap electronic device wich is conected by 2 wires to each battery wich cuts off the charging current at the point it is set to.
This results in all the batteries connected in series of the battery bank to have the same voltage once they are charged to the recomanded Voltage.
This is called balancing or leveling and the most important part of a Battery Managment System or in short BMS.
Here are such devices for sale....have a look to understand. There is nothing more to it and this can be done very easy.

https://electriccarpartscompany.3dca...ower%20BMS.pdf

This has nothing to do with the battery charger and is just used for leveling / monitoring and controlling the voltage of each battery.

Since every battery needs it´s own little device/monitor the bigger the batteries You use the less monitors You need and the more simple it gets.
Since bigger batteries are cheaper per Amp Hour design the battery bank with as less batteries possible

There are marine lithium battery packs plug and play available but they are expensive because they use Your confusion about the subject.

12V 400A Lithium Boat Marine RV Solar Battery Bank-Pack Kit

Hopefully what You will read here is going to change that.

The only other thing requiered is that Your charging sources (battery charger solar charge controller, alternator, generator ) can be programed / adjusted to the requiered voltage of the battery bank

Google or have an orienting look at battery prices here and form Your own opinion.

Lithium Batteries - Prismatic

A good size is a bank of 4 units LifePO4 prismatic cell 3,2 Volt 400 AH.
At 20% depth of discharge this gives You 320 Ah of usuable energy
This will give about the same usuable energy than a 640 AH at 50% DOD lead acid battery bank or aprox 1000 AH at 20% DOD

Here You can find more good info
There is also an interesting story about the different lithium battery manufaturers
Electric Car Batteries: Lithium!

[goboatingnow]

I actually think liFe is as close to drop in as possible. You just need the correct charging setup. The rest is just monitoring , optional or not as you see fit.

Dave


Sent from my iPad using Cruisers Sailing Forum

[hellosailor]

warrior-
fwiw "cheap" is a relative term. It takes more than two cheap wires for a BMS to cut off charging to each cell. You will need a fairly robust and expensive relay to handle 400A without any chance of arcing and with a good working life, as it will routinely control the start/stop of charging. And you need one per cell, so you'll need at least four of them. And, you might want four "safety" devices for when the relays do or will eventually fail. Putting 400A across relay contacts on four cells will call for some robust parts selection. Not impossible--but it won't be a $100 project.
And then too, you will also need three more high power relays to bring the cells back together into series configuration, to let them operate as a 12V battery when you're done.
No, wait, you may also need to do all of this twice, because you'll need an auxiliary battery to use for your 12v needs while the main battery is broken down to 3.5 volt cells that are individually charging. And some more switching and protective and control circuitry.


Wait a minute, what happened to "simplicity" ?!

[goboatingnow]

I agree and this why warrior is off base here

To do a proper Li install

1. You must setup your charge sources to suit Li charging , including terminal voltage , in normal operation your charge sources should never exceed your Li charging parameters. This requires the biggest change. Alternators in particular are major culprits. Modern battery chargers are somewhat programmable , but you have IUI chargers that are wrongly setup for Li.

2, HVC and LVC are protection systems. They should never trip in normal situations. As hello sailor points robust disconnects are not cheap , as are high interrupt fusing

3. Forget about in-circuit balancing , it's not worth it or is it needed. Just monitor the batteries for over voltage , the system should open the HVC protection if you have a over voltage at a battery level , if you have a fault. ( there are ways to protect the alternator )

4. None of this is electrically difficult, but just different from current installs. Arguably these types of systems should be on high value LA too, like AGMs. Save a few from early death too.

Dave


Sent from my iPad using Cruisers Sailing Forum

[nimblemotors]

You are confusing warrior90 wanting a BMS,
and nimblemotorsports charging each cell.
Good thing you don't design chargers, because your design is horrible.
Who draws 400 amps from their 12v house battery?

Originally Posted by hellosailor

warrior-
fwiw "cheap" is a relative term. It takes more than two cheap wires for a BMS to cut off charging to each cell. You will need a fairly robust and expensive relay to handle 400A without any chance of arcing and with a good working life, as it will routinely control the start/stop of charging. And you need one per cell, so you'll need at least four of them. And, you might want four "safety" devices for when the relays do or will eventually fail. Putting 400A across relay contacts on four cells will call for some robust parts selection. Not impossible--but it won't be a $100 project.
And then too, you will also need three more high power relays to bring the cells back together into series configuration, to let them operate as a 12V battery when you're done.
No, wait, you may also need to do all of this twice, because you'll need an auxiliary battery to use for your 12v needs while the main battery is broken down to 3.5 volt cells that are individually charging. And some more switching and protective and control circuitry.


Wait a minute, what happened to "simplicity" ?!

[hellosailor]

Jack-
I didn't design a charging system, so "my design" for one isn't up for review.


And I could care less who draws 400A from their batteries. Although a 2000W inverter will pull a fast 150A by itself. I mentioned 400A because that's what warrior spec'd as his bank size, and in case you aren't aware, a single "automotive" deep cycle battery can put out over 3000A into a crowbar sort, so deigning the critical disconnects to withstand full battery rated power? Is just a quick and convenient compromise. If your charger or cabling gets hit by a crowbar short and the disconnect relay can't open, without arcing and fusing shut, you're still in trouble. Which is why I said you need additional protection on each cell as well.


That's not a "design", that's a quick overview of what some possible complications in a design WILL be, and why "simple" and "cheap" aren't among them.


I've heard your intentions to build a magic box and market it. Computer controls are all nice and good, in principal, but once you start switching around potential high-amperage loads in varying configurations? You'll need more than FETs to do the work reliably.


And I love the way you neatly ignore the fact that one battery, with any sort of single-cell charging system, will still need to be totally switched out and replaced by another battery, while those single cells are taken offline and out of series configuration, to charge them. As Scientific American used to put it, " A simple exercise left to the reader."


Point being, it ain't gonna be as simple as warrior--or you--think. Don't confuse the forest for the trees.