Baroutologos's Handcrafted - Rechargeable LED Hurricane Lanterns

[Trevtrain]

Thanks for the reply here Baroutogolos.

My understanding of electronics is somewhat basic so I am not really sure how much work would be involved in you having to redesign the pcb using alternative topologies. I guess it is something you should consider for the future if your market expands beyond our rather specialty niche here at CPF and other like-minded audiences.

Due to financial limitations, I cannot see myself becoming a customer at this time no matter how much I admire your lights, so I guess you can't really view my observation as a "wish". But I do think that once you design someting for use with 12V, you have to figure that people might leave it connected to a source that is charging. Even campers using 12V solar panels to charge a deep cycle battery may expose your light to overvoltage if remains connected during the day.

Perhaps you could comment further on the internal fusing. Is this in the form of a resettable fuse or will something need to be replaced if the fuse is triggered? Is it easily user-servicable? Would the user understand what triggered the fuse?
I know, lots of possibly pedantic questions but I really want to see your products take the best form they possibly can.


In any case, a prominent warning about not using them in running vehicles might be in order when you ship your laterns.

Cheers.

 

[jonwkng]

Hi Panos,

I see you've been hard at work at your lantern workshop lately. Amazing what you've done with your latest offerings. Beautiful! The pair of Rhewhums have a pretty distinctive design. And I notice you've added a nice 'For Sale' page... Nicely done! :thumbsup:

For anyone who's deliberating about getting one of these beauties... Get them while you can. The price that Panos is asking for them is a steal considering the amount of workmanship and the parts and electronic expertise it takes to modernize them. And they're strictly small volume items.

My lantern has been a centerpiece mood light at the dinner table in many a family gatherings and been out on a couple of barbeques. Great conversation starter. Beautiful, rustic, yet practical. And I just love the warm tint of the SMDs that Panos uses.

 

[Baroutologos]

@ Jonwkng,

I am really more than happy to hear you saying that! Thanks a lot for your kind words!

@Trevtrain,

Yes, a redesign always involves considerable time from experimenting and finding the right component values in the breadboard till you procure parts and "print" the circuit as it should be. I am intending in the future to have that option (especially for larger lanterns).

Previous lantern models, made use of ressetable PTC fuses when exceeding certain amperage values. When working with 3-5 volts this is adequate, when going up to 12volts (that present a mismatch to the charging voltage of cells) then a really fast fusing is needed in the mSec range or serious damage may occur.
Thus newer models use a combination of PTC fuses for the cells (low voltage portion) and fast fusing to the potential higher voltage option.

When fast fuse has gone off, user can readily tell since no current goes to the lantern (but still lantern can work on cells)
Fuses can be easily changed and the models are common and readily available.

Thanks to David from Florida (owner of Rhewum lanterns made) a user guide was made.
http://www.rechargeable-led-lantern.com/wp-content/uploads/2014/04/barous_lantern_guide_v1.pdf

So in the future, in circuit terms my goals are towards achieving greater output (a 1000-1200 lumens will be nice ) and even greater voltage versatility.

cheers,
Panos

ps: now the lantern circuits are mainly with SMDs with few hole-through components (photos pending)

 

[Baroutologos]

Leds and Leds..


In this post i will show how i am assembling my own custom bulbs fit to my lanterns.
As known, those are replaceable in the unfortunate event of a failure so as to assure lantern long life.


After many topologies in electrical and mechanical terms i have concluded to the pentahedron (since 360 degrees light with no dark corners is achieved from 120 degress typical leds beam)
For leds i used samsung chips 2323 2700K and now i switching to Cree XHG ones. Although similar in electrical parameters and output, Crees are quite more fragile during handsoldering, a daunting task that eventually must be evolve to reflow soldering.

Pictures worth ,000s words
http://www.rechargeable-led-lantern.com/wp-content/uploads/2014/05/bulbs-1.jpg
http://www.rechargeable-led-lantern.com/wp-content/uploads/2014/05/bulbs-5.jpg
http://www.rechargeable-led-lantern.com/wp-content/uploads/2014/05/bulbs-6.jpg

I have assembled also a draft vid in order to see how they are run into place. https://www.youtube.com/watch?v=eIVDshhtvKk

Just to keep this thread updated

 

[Baroutologos]

Have you conducted any updated run time tests with larger, newer batteries? I see that your lantern states that it can take 1 - 3 batteries. I was just curious of the run times when using 3 x 3400 mAh Panasonic NCR18650B batteries?

RI Chevy

Hello RI Chevy,

I must confess i have not conducted run time tests with those newer cells, but i have done run time tests with common 2000 mAh cells, 6,3 V Lead acid battery, 12,5v lead acid battery etc etc (cells removed above 5 volts input).

Lanterns have an inside trimmer to adjust max power between 2-5 watts. (3.8 watts is the recommended setting) Whatever is your power source Wh rating, you just have to do the maths to estimate run time.
Based on maximum Ah rating is a bit tricky to estimate runtime for two reasons.

1st) internal boost regulator that maintains lantern luminosity irrelevantly of cell's voltage consumes an growing current over time at a given power setting (so you need to know Wh rating at say 0.5A draw)
2st) Cells must be fully charged, that means trickled charged. My way that cells are charged inside lantern give an 80-90% charge state in the C2-C6 (1-3 cells or C8 for 4 cells) charging cycle.There is a trick mentioned to tricle charge them to higher level also.

Anyway, in fewer words, newer more energy densier cells will keep the lantern more time lit according to the additional energy content respectively.

cheers

 

[RI Chevy]

Thank you sir. :thumbsup:

So could your lantern be adapted to use larger, multiple 26650 cells? I think they are almost D-cell sized.

 

[Baroutologos]

Hello RI chevy,

My lantern is not actually a standard lantern. I use a plethora of mostly old and restored lanterns that range from medium-small to large size. Small / medium sized lanterns can at best take only 18650 cells.
Larger lanterns if applicable can accomodate 26650 cells. I have given much thought in the past, but the use of such cells does not bring benefit to an extraordinary degree to justify the fuss. Other considerations arise as i have not spotted an appropriate 26650 cell holder etc..

By the way 26650 cells are like C alcaline cells that are longer.

Perhaps in the future.. who knows?

 

[RI Chevy]

Very good. Thank you for the update.

 

[Baroutologos]

It has been a while.. but here i am back again.

Even though the constant pressure of reality prevent me from issuing new lanterns, at least at the rate i would like to, the time i had on my disposal for lantern making was "invested in try addressing a series of issues towards lantern improvement and particularly developing a circuit that will enhance lantern's flexibility in operational terms, that campers will find it interesting and useful.

Those alterations resulted to a newer way of making my lanterns (and somewhat more difficult too) calling it λ series (L, greek word λ, right after K)

Changes:

* bottom lid closure
* Cell holder and velcro fastening
* potentiometer fastening
* Circuit fastening
* λ series circuit

Bottob lid

The snap on tin-can style bottom lid closure is being replaced in the new series by screw-in-place lid style.
three screws are used and my B mark goes anaglyph in the bottom.

Cell holder and velcro fastening

For easier and more robust assembly cell holder and velcro is screw to lantern chassis, being separated.
Below its a lantern's tank overview. Dummy circuits are screwed in place whereas the cell holder and velcro is not.

Potentiometer fastening

Potentiometers in the new making style are replaceable, are screwed inside lantern's wick turret and are stress free from shocks coming from wick controller. This simple thing i must confess took me considerable time to perfect since tolerances are really tight so as not be any slack.

Circuit fastening

The new type circuits can operate at considerable more power, and can take charge from a voltage range during cell charging. This creates some heat that needed sinking. Internal circuits that traditional split to two parts (the power section and the lead control & charge section) rest screwed on 1 flat copper heatsink and a plain iron sheet one.

Notice at the new circuit power section's heatsink, lantern's serial number is impressed to copper.

***

λ-series circuit presentation follows

 

[Baroutologos]

Regarding the new L-series circuit employed:

The right collumn circuits composed from the power (PWR) section (above) and the Led control & charge (LCC) section.
The left collumn circuits is the K-series + PWR and LCC sections respectively:

What's new L-series circuit

PWR section

Power section is a SEPIC topology, run by the proven FP5138 IC. SEPIC means isolation between input and output.
For enhanced efficiency bootstrap is employed and the standard power regulator pot is located on that pcb.
Runs about 85% efficiency at virtually all power levels and employ heatsinking (for running at higher power)

voltage range: 3-18volts (input voltage does not affect output voltage) Easily the lantern can be plugged to an RV 12v outlet that actually peaks some 15 volts and works like charm.

power: @ 3 volts max 6 watts, @3.5volts 8watts, @4volts 10 watts, @12 volts LED limited
note no yet developed lighting elements able to run above 4 watts (450 lumens), although soon they will be, intended to go as far as 1000 lumens or more.

power section has active shortcircuit protection plus current limiter (at 0.6Amps) irrespectively output power. (meaning voltage x current)

LCC section

The other half circuit controls the familiar red LED's function. i.e
* cells charging LED on - charging completed LED off
* cell drop below 3.2 (+- 0.15v) LED on
* current input to lantern more than 0.5amps LED on. (this helps on trickle to estimate charging)

Outside power pollarity protection . Internal Cells reversal polarity protection (95%)

(Charging + lantern's consumption) current max 1.5 Amp @ 5volt Input, 1,7A at 5,8V input
Active fusing at more than 2 A inrusing current for more than 10mSec. Resets on external power removal.

Cell charging voltage 4.5 - 7 volts (traditional 5v charger + 6v lead acid battery option)
Above 7 volts lantern works normaly but cells are electrically ISOLATED from power source. So no need for removing cells when the lantern is pluged to a 12-15v power source, but they do not charge also.

**

I know this is not the ideal circuit but i suppose there is not an ideal circuit, just reliable circuits that give us options about versatility and power output, maximizing in the same time ruggness and efficiency.

Just for the record it took a huge amount of time to develop from PCB design and making till bug elimination.
I am extensively testing it mounted on lantern (real conditions) with great success so far.

**
Comments and discussion welcomed!

Cheers,
Barou

 

[Poppy]

Barou,
Boy oh Boy, you must love to tinker! :thumbsup:

Just building those bulbs must take a lot of time, and a ton of patience. I wish I had your knowledge, and patience.

A couple of years ago, I bought a 6V SLA rechargeable lantern (a compact spiral tube florescent.) I then went out and bought a few back-up SLA batteries for it. That however, was the year before I was introduced to Li-Ion 18650s. I appreciate having multiple power, and charging options, for a light. I have modified a few of my 6V LED lanterns to run off of a 5V USB source, such as a power-bank. I didn't do anything fancy, I just wired a USB cable to the battery box, and the power-banks are external to the unit/s. I did this to the Energizer folding lantern with "Light Fusion Technology", the energizer "Pop up Lantern", and a 4D cell GE Enbrighten Lantern. As a result, they have the option of running off of a wall-wart with 5V USB output, its internal batteries, or the external power-bank. The power banks can be charged from essentially any USB output source, such as a car cigar lighter with a USB adapter, or a built in USB port (as more newer cars have), or a wall wart.

All this to say that if I were working on your project, I might ditch the 6V SLA and other voltage options, and pack the unit with 2-3 removable/replaceable 18650s in parallel, but with each having it's own over/under charge protection, (so that a person does not have to concern himself with matching batteries.) I'd supply it with a USB charging cable. But to be really cool, I'd also look into wireless charging.

 

[Baroutologos]

Hello Poppy!

I am glad you the first to reply this thread after its restart. thanks.

All this to say that if I were working on your project, I might ditch the 6V SLA and other voltage options, and pack the unit with 2-3 removable/replaceable 18650s in parallel, but with each having it's own over/under charge protection, (so that a person does not have to concern himself with matching batteries.) I'd supply it with a USB charging cable. But to be really cool, I'd also look into wireless charging.

You mean like this?

Since the first lantern made, the concept was to be packed with 2-4 18650 Li-ions cells. Nothing changed (except requests for not having cells), only options added.

***

Wireless power transfer huh its a really cool option but of not that great added merit i am afraid. One main obstacle to it, is that lanterns are made out of tin. Wireless power has a difficult time transfering via metal sheets since it creates eddy currents on their surface (heating them) and greatly diminishing output. Notice that devices that employ wireless power transfer, have their receiver / transmitter ends made of non conductive materials. This can be partially tackled by proper coil orientation but again.. it would be a feat i guess.

The other thing is that a tansmiter will require a circuit on its own + the traditional 110/220 ->5v converter. + some circuitry in the receiver's end.

Actually i am more intrigued sometime in the future at developing a relatively small photovoltaic panel foldable or/ embedded to the currying case for providing "eternal" light.

But that just me

cheers,
Barou

 

[Poppy]

Hello Poppy!

I am glad you the first to reply this thread after its restart. thanks.



You mean like this?

Wow!! You really work FAST!

I'm glad that I was able to help


Regarding wireless charging, there are Qi chargers on the market, so there would be no need to reinvent them.

I don't know anything about building a receiver, but I imagine that the bottom of the lantern could be replaced with plastic, and not ruin the aesthetics of the light. Anyway, it was just a thought. Perhaps it would take more effort than it is worth.

How do you charge the batteries now? I didn't see a charging port.

 

[Baroutologos]

hello again Poppy!

I have somewhere mentioned in this thread that lanterns (all) are equiped with 5.5mm outer 2.1mm inner female (- , +) power jack for connecting with the appropriate male jack from wall charger or 6v SLA or 12-16v car battery (so as to get power).

I have failed to explicitly state this to my blog also. So, here are few pics

Notice the powerjack at lantern's tank in the lower right section of the tank.

This is a typical charging mode when lantern is either off or on. The LCC circuitry section of K series + or λ series has a somewhat sophisticated charging control that gives moire amperage during low cell voltage, and goes to lesser as cell voltage climbs up (but never ends so protected cells are must or slowly cells will boil)

RED led is indicator in the simpler K-series circuitry and once charging is completed it goes off.
Same is true for λ-series. However, In λ-series circuitry due to increased amperage for charging and working (can go higher power), the LCC sections distributes the incoming max amperage (1.7 amps) to either charging or working. e.g. If working is in minimum power setting charging gets almost all incoming amperage. The reverse is true.


cheers,
Barou

ps: thanks for indicating off-the-self wireless chargers. By the way, replacing bottom lid with plastic is not an attarctive option. The magic is in the old chassis.

 

[Poppy]

hello again Poppy!

I have somewhere mentioned in this thread that lanterns (all) are equiped with 5.5mm outer 2.1mm inner female (- , +) power jack for connecting with the appropriate male jack from wall charger or 6v SLA or 12-16v car battery (so as to get power).

Hi there Barou

Thanks for the response. I guess I missed that, but it is certainly nice that it can be recharged from such a wide variety of sources!

Overall, you do nice work. I can see that they are a labor of love. :thumbsup:

 

[Poppy]

Barou,
Intrigued by the idea of wireless charging, I did some googling and found that transmitter and receivers can be had for less that $20 a package. It seems that the receiver coil can be glued/taped to the outside of the can, with wires running inside to the batteries/charger circuit.

I am thinking that in a home with the proper decor, that your lamps could be the perfect replacement for the standard lamp. Also that it would be neat to be able to carry it to the back patio in the evening with fully charged batteries, and when done for the evening, to just put it back in the den, or wherever, on its charging plate. The problem would be in the need to modify your charging circuit so that it would shut off once the batteries are fully charged.

 

[Baroutologos]

Hey Poppy!
Outside of the can? like thinking out of the box! hehe.. to be honest i have not tinkered with low powered wireless charging so as to know its potential and limitations, especially those of the trade availabla at 20 $.

I must admit, with the right craftship, the charging station (plate) could be formed like a pedestal that the lantern will rest and add beuty to it.
Its quite feasible to be done i guess.

When using protected cells and assuming wireless charging does not interfere with circuit's components, the cells would shut off once they fully charged.
I can see no problem there.

cheers,
Barou

 

[Poppy]

LOL... Barou, I think I can see wireless charging in your future

Have a great day my friend. :thumbsup:

 

[PapaLumen]

Hi, you do great work! Personally, I don't think wireless charging is necessary, especially if it raises the price.

One question, you mention "The LCC circuitry section of K series + or λ series has a somewhat sophisticated charging control that gives moire amperage during low cell voltage, and goes to lesser as cell voltage climbs up (but never ends so protected cells are must or slowly cells will boil)"

Are you saying that it will not terminate when batteries are full? I don't like to rely on battery circuitry for protection from overcharge. Maybe I have mis-understood.

Thanks and again, great work!

 

[Baroutologos]

Hey PapaLumen!

Nope, you understood it perfectly. IF cells are charged fully AND protection circuit fails to cut off, THEN they will slowly overcharge, then perhaps boil and spoil the cell, rendering it useless. (it was pretty useless from very start since since protection circuit did not function). This is why, and for other reasons as well those circuits take protected cells only.

For those concerned about the possibility of overcharging leaking, i have tested that most cells even overcharged (unprotected or protection circuit spoiled) will sit idle for long periods at 5volts drawing few current, and hardly call them (over)heated and not leak at all. (assuming standard 5v charger is used. not tested yet with a power source of e.g. 6.5 volts)

But for those intended to have this type of lantern used permanently hooked to a charger, and occasionally unhook it (from charger) and walk it around, i guess i should revise circuitry so as to have this added double safety feature (+to do list).
So far i had the notion to have it as portable with standard on-board charging cells.

***

One method for telling spoiiled cells in current made circuits is by looking the red LED. Usually certain number of cells (1-4 depends lantern model) at given depth discharge will take given amount of time to fully charge and then red LED go off.
If it nevers goes off*, at charging brightness, then something is definitely wrong.

***

Bottom line, thanks for the tip, It can be done. Sure.

cheers,
Barou

ps: thank you guys for your kind words
* some lanterns have red LED never going totally off, resembling as a dim charcoal in the darkness so as to spot the lantern easily.