The Li or Order/Power of Shen (God): Reverse-Engineering the Chafon 500 watt lithium battery Solar-Car DC/AC generator as the Onewheel

So I got the 100 watt solar panels from Harbor Freight. These are "old skool" amorphous panels so that they work in the low sunlight of the North. They have a DC male connection or else a SEC connection (that's the auto term). OK I first have to hook up the battery to the charge controller before I can hook up the panels to the charge controller...

BUT - the Chafon battery has a built in charge controller. Or so we are led to believe. Actually we are told - just don't use any panels over 120 volts and preferably 100 volts with a 5 amp limit for charging.

But ... here's the deal: Without actually opening up the Chafon 500 watt generator - I can infer that this is what is inside it.

So that's based on the specs from the questions answered by Chafon.

18650 battery pack, including three series and eight parallel 26000mAH 18650 Lithium ternary battery

SuPower 3.6V 3.7V 4.2V 18650 26Ah Lithium ion Li-ion Rechargeable Battery Pack Max. 5A with built-in protection circuit board

 So the circuit fuse is 8 amps for AC... for plugging in. So that's 960 watts.
So this 500 watt comes with a Car battery JUMP starter that is 300 amps.

So that has to over-ride the AC fuse for input - as 300 amps x 12 volts = 3600 watts.

So Chafon then said they stopped including the Jump starter for cars since it decreased the life time of the battery. Yes because you are short-circuiting the lithium cells if you use the jump starter.

Now if the battery is 500 watts but has

built-in 36 pieces, 3.7 V, 26000 mAh 18650 lithium battery, so the theoretically capacity is 36 * 3.7*2.6 (amps)=346.32

so than that's watt HOURS and so you figure a Jump Start is about 1 minute or so. The battery has to be 80% charge so... should be plenty enough of a surge.

O.K. so now we know why typically you want a 5 amp limitation on charging, to spread the 12 volt amps down to 2.7 amps.

And so people reported that the DC adapter for the Cigarette car charger - that cord that comes with the Lithium battery - it allows a 12 amp charge to go into the battery! But the cord can only handle 11 amps and so the cord melts.

And so then people recommend getting an AC inverter for the cigarette car charger - and so I'm getting an 80 watt inverter - to convert my car's 15 amp output back into 5 amps.

So that solves the DC overcharge problem.

So it's that it has a charge controller but more like a 5 amp circuit fuse breaker for the DC charging.

The AC input has a "pass through" to the AC output - so you don't use  up the battery - and so the Lithium battery doubles as a "universal Power source" that will then KICK IN to the battery if your AC power goes out.

This also means you can USE AC power from the battery while you charge up the DC battery.

But if you use DC power while charging up the DC battery then this might over ride the internal 5 amp limit - as someone reported happening.

And so as I mentioned - I can not hook up my charge controller for the 100 watt solar panels - but I do not NEED the charge controller, as long as the amps are under 5 amps - which is the case for a 12 volt parallel series.

OK so if am charging and the 80 watt AC inverter for the car's 12 volt then kicks out 6.6 amps - is that gonna trigger the built up circuit protector? How's that work?

We recommend that recharegable lithium battery be charged about once per half 3 months to prevent over discharge

What? I think they mean make sure it is fully charged every 6 weeks. Chinglish.

In the extreme case of internal short circuit, the safety of the pores can be quickly discharged from the internal exhaust, thus curbing the battery expansion, in order to avoid the risk of battery explosion, to ensure the safety of personnel
Top Button (Positive) made of Nickel (Ni) - Negative made of Copper (Cu) for an ideal conductivity and durability.

OK good to know.

 In the normal use of CIVICTOR 2400mAh 18650 battery, which still retain 75% of the original battery capacity after 1500 times fully charged discharge cycle; however as usual the other 18650 battery in the market only have at most 500 times, so CIVICTOR 2400mah rechargeable 18650 li-ion battery absolutely is high capacity battery.

DANG!! I just have the 500 times rechargeable type. oops.

 Several partial discharges with frequent recharges are BETTER for 18650 lithium-ion battery than one deep one because there is no memory effect.

 Highly Recommend CIVICTOR 18650 charger AR-XI-LU that limit the charging voltage to 4.2 V to protect your 18650 lithium battery

OK so what kind of circuit protection is there?

OH - there's a 5 to 10 amp protection circuit module. So that would cover the 300 amp surge for the battery jumpstart. 3.7 volts x 36 x 10 amp... if you have the 80% minimum charge on the battery... So must be one of these in the Chafon 500 watt - or something like it:

 Protection Circuit Module has special time delay function and high rate Mosft component.  It is especially designed for 18.5V Li-ion Battery Pack which requires high pulse current up to 85A within 10 ms.

Protection Circuit Module Specifications  For 18.5V Li-ion/Li-Po Battery  Pack
Model：PCB-LI18.5V10-85A
Over-charge protection voltage	4.280±0.025V
Over-discharge protection voltage	3.000±0.05V
Over-current protection	85±10A
Maximal continuous Discharging current	10A
Maximal Current consumption	20uA
Short circuit protection	Automatic Recovery
Protection  circuitry  resistance (B- TO P-)	≤30mΩ
Dimension	88mm(3.5") x 34mm(1.3") x 6.0mm(0.2")
Weight	11 grams
P+/P-	P+ = Charge+ / Discharge + P- = Charge- / Discharge -

Anyway I found one review stating the SAME thing I discovered - that the solar panel connection wires "appeared" to be reversed - and the person has stripped the wire to insert it into the charger. They twisted the wire FIRST. Yes I tried this but I didn't twist the wire, nor did I reverse the wiring - since the sun had disappeared. haha. I will get a wire stripper tomorrow to make the connection longer - and maybe the sun will be out.

But then next week I'll get the adapter - to hook up the solar panels directly to the Lithium battery - since I don't need the charge controller anyway. The Charge Controller is for Lead Acid batteries and so actually would SLOW DOWN the charge of this lithium battery. So the other thing about Lead Acid batteries is they weigh a LOT more.

This Lithium battery pack, inverter, charger weighs less than 8 pounds while a comparable Amp Hour Lead Acid battery would weight THREE TIMES MORE!!! Also you can only "discharge" the Amp Hours to HALF the amount!! So the capacity is 50% greater on this battery for 3 times less weight.

OK here is someone using that PRECISELY SAME type of a lithium battery cell that I have in this 500 watt charger

Only they are trying to set up the Protection Circuit Board themselves. Let's see what people say...

these BMS boards effectively go to open-circuit, thus isolating the battery, once full charge is reached. I've verified this many times with a bench supply set to 16V with a 10 ohm power resistor in series, with using the exact same BMS board you linked! The voltage at the input/output point clamps down to under 12V until the battery reaches full charge, and then springs back to 16V, while the cell combo sits at 12.6. Granted, this is not the fastest charge, so eventually you can go to a lower resistance.

Wow so it really is a type of built-in charge controller. Pretty cool.

 And most battery management solutions may be capable of 4-5A "fast" charge; so four of those simultaneously would be 20A. So theoretically you could either "slow-charge" them all with 2A, or "fast-charge" them all with up to 20A (assuming the batteries are rated for this.) I'd personally recommend not fast-charging them, as it would require a massive power supply and will generate much more heat.

 Some can have self-discharge rates as high as 30% or more per month. So if your device isn't used in 3-4 months, it may be completely dead.

 Good to know!!

It has an over-charge protection circuit, which means, you can't over charge it, nor short it out. but for a 3 cells batteries to fully charged, you need at least 4.2v x3 = 12.6 volt input;

OK now I get it - the 12.6 is the minimum charge rate voltage!!

 Overcharge protection voltage for single cell: 4.35V
Over discharge protection voltage for single cell: 2.40V
Over current detection protection: 4-6A
Supply current: Max 30uA
Short circuit protection
Protection circuitry resistance: <=50mohms

The PCB prevents overcharging because the delicate lithium ion chemistry of the battery can be damaged if charged with too high a voltage and the PCB will cut power to the cells if you did so. This should not be a problem if you charge with a smart balance charger. If you charge a cell with 4.2 volts, then the cell voltage will never rise above 4.2 volts, even if you charged the cell for weeks. You still don't want to charge a cell beyond the point at which it is charged. A smart charger will turn off once it has finished charging.

Many batteries can be discharged all the way to zero volts, this is not one of them. If the voltage of a lithium ion battery dropped to zero, or even below 2 volts, it would be damaged, and would never charge back up. Cell phones have this same protection. If you measured the voltage of a "dead" cell phone battery it would probably read 2.5 volts.

Over drain protection is necessary because this is a small PCB with tiny components and can only handle so much current. It shuts down to save itself when drawing between 4 and 6 amps.

Supply current is the current draw from the electronics on the PCB. It is practically nothing and will not drain your battery.

Short circuit protection means the PCB will turn off if it detected a short; if a wire became disconnected or if the wires crossed.

Protection circuitry resistance is the resistance caused by the PCB. All circuitry produces a little resistance. Again the drain is so little you will not notice it.

 18650s fall to 80% capacity after 200 cycles.

 The cells are a common format, and therefore widely available and cheap, called 18650s because they are 18mm by 65mm. They use 6800 18650s in the Tesla Roadster!

  that 2.6 amp hour cells have been the industry standard for years.

 If your battery shorts, it will most likely heat up and smell like fried electronics. That's what happened to mine a few days ago. It was an easy fix actually. I needed to more insulation between the stacks of batteries

However, worst case scenario, it could catch on fire when you are not at home and burn your house down. That doesn't mean this is a terribly dangerous project, you just have to be careful. Many projects on this site could end in fires. Only take on this project if you have a good idea of what you are doing and understand the risks.

A simple precaution is to break the battery in while it is in a bucket of sand or on a bit of concrete at least 8 feet from anything combustible. By breaking in I mean charge it and discharge it a few times to make sure it works with no problems.

This is the company in China that made the lithium batteries -

The English translation of the word "LISHEN" in the mark is "power of God"

weird

OH I get it now! Li and Shen. Cool!  funny - I already knew the meaning of BOTH those words from studying Daoism!!


So they are supplying Electric Bicycle batteries now...

So there is an "underground Catholic" church in Tianjin China where these Lithium batteries are made. My guess is the "God" reference in the trademark is then subversive!

Traditional Daoism in Tianjin?

google book

  Ironically, the environmentally friendly image of electric cars and green technology belies the environmental impacts associated with lithium mining in South America.
Following the scrapping of mining export taxes by President Mauricio Macri, Argentina has emerged as the pre-eminent producer in South America’s "lithium triangle," which also encompasses Bolivia and Chile. The resulting surge in investor interest in Argentina could see investment in the sector top $20 billion between now and 2025. However, as investment grows, so does the number of legal challenges from indigenous and rural communities fighting against the industry’s demand for water and land.
According to Verisk Maplecroft’s water stress index, the lithium-rich Puna highland desert of Salta and Jujuy is classified as "extreme risk." Conflict between mine operators and local populations over water rights have led to 33 indigenous communities from Salta and Jujuy filing legal challenges against lithium operations in Laguna Guayatayoc and Salinas Grandes.

A potential ruling in favor of the communities by the Inter-American Court of Human Rights is unlikely to halt operations, but local demonstrations against the projects might create continuity issues if they escalate to the extent of protests that we see in Peru.

China now effectively controls half the world's lithium production - Quartz

https://qz.com/.../china-now-effectively-controls-half-the-worlds-lithium-production/

May 30, 2018 - Tianqi Lithium, a Chinese company, recently paid more than $4 billion to become the second-largest shareholder in Sociedad Química y Minera (SQM), a Chilean mining company. The deal gives the company effective control over nearly half the current global production of lithium, a critical component in battery technology.

OK so I kept seeing mention of this "OneWheel"

https://onewheel.wiki/Charging_on-the-go#AC_battery_pack 

That link is truly a generic "reverse engineered" Chafon !!!

AC battery pack (e.g. Chafon)

- Most common solution - Safe - Includes multiple USB ports and outlets

- Heavy (7lbs w/ battery and charger) - You must carry charger too - AC->DC is inefficient from energy perspective - Expensive ($300+) - Battery capacity readings are wildly inaccurate

That's how the link was posted.

Only there's a few problems with their claim.

I got it for $50 less then they claim it costs.
You don't HAVE to carry the charger - if your car is the charger.
They do list the "car inverter" option but then state - make sure it can handle 300 watts!!
That was the purpose of this blog post - to make sure I had that covered.
Then they claim the Chafon is a "modified" sine wave - well MAYBE the smaller version. But the 300 watt has been tested as a pure sine wave... which is another way of saying is has PASS THROUGH as a "Universal power source" for electronic devices and digital signals.

They claim the Chafon is an AC pack - but it's also a DC pack - it's a DC battery! You can charge it DC.

So this DIY page really "sells short" what the Chafon really is. Pretty funny.

I had no idea there was a whole sub-culture trying to DIY a "better" Chafon - but I don't think they really did it at all.