Arlo - dual 18650 DNA20/30 step-by-step how-to

[mamu]

I've been wanting to do this project for a while and kept putting if off because of the time involved with stopping the build to take pics and take notes then gather the pics and notes and then make sense of it all when writing the tutorial.  But it's been calling my name so I gave up and just got er done. 

Arlo is 100mm x 60mm x 23mm, so not too big for dual 18650 batts plus all the circuitry plus internal charging.

Here's the step-by-step how-to: Arlo how-to

All done and ready to close er up...








For those who want to jump right in and do it to it, here's the wiring I did with this case...

[Breaktru]

Looking good mamu. Well done.
Your tutorial is excellent.

[kortt]

Nice mamu, always love your step by step guides.  Have learned a lot from them.   

now if I could just get my hands on a dna30 module

[rdwilliamson]

Another great looking mod!!!!

Loving this one.

[mamu]

Thanks guys!

Been vaping all day and still lots of charge left!  I love these dual batt mods. 

[Mandro]

Thanks for the tutorial mamu, it's easy to follow and as a few techniques that can be used in any box build.
The finished mod looks great and once again the internals are very neat and tidy. 

[CraigHB]

I love these dual batt mods.

For sure, they're a bit large, but they provide a boatload of run time, really nice.

[Boonos]

Awesome - thanks for the tutorial

[Littlefeather]

For those who want to jump right in and do it to it, here's the wiring I did with this case...


Ok, little confused here on the fusing you’re showing between the DNA20/30 on this build tutorial and wiring diagram. In previous build posts with parallel 18650’s and the DNA20 using this fuse 16R300GU (PTC RESETTABLE 16V 3A RADIAL), my understanding that it was determined that 2x fuses per positive battery leg were required to achieve the reverse polarity and battery failure safety to save the boards bacon.
For the DNA20 you’re showing here it’s only calling for a single fuse (MINISMDC260F/16-2) off each positive leg before meeting at the parallel battery junction and 2x same fuses (in parallel) for the DNA30 at the same location.

This confused me because with my DNA20 and single 18650 build I used 2x fuses 16R300GU in parallel on the positive battery connection leg as recommended and thought 2x fuses per battery leg would be required in a duel parallel battery scenario for the DNA20. Did I miss the boat and/or over complicating it?

[mamu]

For reverse polarity protection each batt when using dual parallel batts does not have to have 2x fuses. 

For reverse polarity protection when using dual parallel batts, each batt must have its own fuse and you can split the total hold current needed among the batts. 

For the DNA20 a total of around 6A hold current.  2x 3A for single batt = 6A.  1x 3A per batt for dual parallel batts = 6A.

For the DNA30 a total of around 12A hold current.  2x 6A for single batt = 12A.  1x 6A per batt for dual parallel batts = 12A or 2x 3A per batt for dual parallel batts = 12A.

[Littlefeather]

Thanks Mamu

You've cleared my confused state. And, I was!

[Jasen]

Howdy from the new guy.
Mamu,
Great write up, it answered a few questions  for my 1st mod which is similar to yours from the Xinbo box, if the slow boat from China hasn't sunk.
I should have all my IC parts Mon/Tuesday to build Breakthru's TIPTR08100WVD circuit.

Jasen

[deftones]

Awesome tute again, thanks mamu! Working on my own twin right now too!
Funny how you kept the leds of the original box for charging status and flashlight. 
Noob question of the day: why did you bypass the charge input of the board?

[SDaddy]

Great little tutorial!  Going to use this for a VAMO pcb setup!

[mamu]

Awesome tute again, thanks mamu! Working on my own twin right now too!
Funny how you kept the leds of the original box for charging status and flashlight. 
Noob question of the day: why did you bypass the charge input of the board?

I didn't bypass the charging board's input or output - it's all still functional.

[Boonos]

thanks so much for the well explained tutorial, even though I'm not using this setup, I've learnt loads.

[deftones]

I didn't bypass the charging board's input or output - it's all still functional.

Maybe I got this wrong but there is nothing connected to the "CHG" on the wiring pic?

[mamu]

Maybe I got this wrong but there is nothing connected to the "CHG" on the wiring pic?

There's no "have to" with using the DNA CHG pins.  Wiring the charging board's + and - either to the DNA CHG pins or wiring directly to the + and - batt as I did with Arlo and as shown in the wiring pic will get the job done of charging the batts.

If I'm not using Evolv's micro usb charging board and using instead a foreign usb charging board that has other features than just input charging, I like to bypass the DNA CHG pins in case there should be some sort of compatibility issue.

[Jasen]

Mamu,
I'm still waiting for my Ximbo box so the only look inside I've had is from your write.
I had the notion of parring down the USB charging circuit to just the micro USB for charging the batteries only, no accessory charging, flash light or batt stat LED's. Am I getting carried away here, just buy another USB charger?

Jasen

[mamu]

Modifying the charging board that comes with the case to get just the usb input charging would be a hard thing to do as you'd have to find all the traces on the board for it.  I'm not capable of doing that. 

You could replace the charging board with Evolv's micro usb charging board if you want to go that route.

I had thought about just eliminating that entire section and parring down the case for just the batts and circuitry so to save on height, but that's a no go as you'd not be able to attach the back cover since the spring loaded part of it is in the charging section of the case.

[Jasen]

I kinda had that in the back of my mind, but hey,a  guy can dream can't he. I can get a charging board locally, like Evolves, from the last remaining electronics store in 250 miles

Thanx for the insight,

Jasen

[deftones]

There's no "have to" with using the DNA CHG pins.  Wiring the charging board's + and - either to the DNA CHG pins or wiring directly to the + and - batt as I did with Arlo and as shown in the wiring pic will get the job done of charging the batts.

If I'm not using Evolv's micro usb charging board and using instead a foreign usb charging board that has other features than just input charging, I like to bypass the DNA CHG pins in case there should be some sort of compatibility issue.

So I'd better bypass the charging input if I'm using a third party USB board. But if I use Evolv's USB, then should I bypass it too? What is the benefit of using the CHG input? I am asking this because my box is done now    and the last thing to add is this, and I was wondering where I should solder this without any safety issue. 

[fullthrown]

Awesome tutorial! This is exactly what i needed. I recently ordered a DNA 30 board and i had a few questions.
1. Are the fuses necessary? Are they simply keeping the board from frying?
2. Where can i get the fuses required for the DNA 30? Im planning a parallel 18650 build with the evolv charging board.
3. I know you pretty much explain it in this tutorial, but there was only a picture for the DNA 20 fuse wiring (if im not mistaken), could you possibly explain what the DNA 30 fuse wiring would look like. (basically what do parallel fuses look like and does it fit into this build).

Any help would be much appreciated.
Thanks! and again, awesome tutorial

[Breaktru]

So I'd better bypass the charging input if I'm using a third party USB board. But if I use Evolv's USB, then should I bypass it too? What is the benefit of using the CHG input? I am asking this because my box is done now    and the last thing to add is this, and I was wondering where I should solder this without any safety issue. 

The charging input and the battery input on the DNAs are exactly the same.
The benefit of the charging input is not having to tap into the battery. Not a big deal.
You don't need heavy gauge wires for the charger. Current will be lower. 500ma or 1000ma depending on which charger you're using

[deftones]

Sorry Breaktru, I don't get it, I'm a electronic noob don't be mad. 
I meant: is there any benefit between "connecting the USB to the CHG input of the DNA board" and "bypass the DNA board CHG input and connect the USB directly to the batteries (not the batt in of the DNA board)", or is it the exact same thing?
Is the CHG input here on the board just for convenience (just like the fire, up and down switches), or is there some kind of "extra safety" granted from using it?

[mamu]

It's both, deftones - using the CHG on the DNA is for convenience like the onboard buttons are and whatever onboard protection the DNA has for input.

You can wire it up however you want - use the CHG on the DNA board or bypass it.  It really makes no difference as the CHG traces on the DNA board go directly to the input.

I've had 2 failures with using the CHG on the DNA though.  I talked with Brandon about this and he speculated that maybe the traces from the CHG to the input got fried from some sort of surge or current. With those 2 boards, I bypassed the CHG and wired the usb + and - directly to the batt and everything was aok.  Never did find out what the exact failure was with the CHG.

When I'm using Evolv's micro usb charging board I wire to the CHG on the DNA board as Evolv's usb charging board has no protection other than overcharge.  When I'm using a foreign usb charging board that has additional features and onboard protection I wire directly to the batts.  It's just something I do, it's not something you or anyone else has to do.  As modders we can opt to do what we feel comfortable with.  It's our decision, our build.

Awesome tutorial! This is exactly what i needed. I recently ordered a DNA 30 board and i had a few questions.
1. Are the fuses necessary? Are they simply keeping the board from frying?
2. Where can i get the fuses required for the DNA 30? Im planning a parallel 18650 build with the evolv charging board.
3. I know you pretty much explain it in this tutorial, but there was only a picture for the DNA 20 fuse wiring (if im not mistaken), could you possibly explain what the DNA 30 fuse wiring would look like. (basically what do parallel fuses look like and does it fit into this build).

Any help would be much appreciated.
Thanks! and again, awesome tutorial

It's your option to use fuses or not.  With the testing I've done with them I've found how valuable they are in protecting the batts from meltdown and the circuitry from frying in cases of overcurrent, especially with reverse polarity with this boost circuitry.

I listed the part number for the fuses I used in this build in the tutorial.  Go to octopart.com, plug in the part number, and you'll find who sells that part and at what price.  You don't have to use the fuses I listed though as there are options - you can use 2x 3A fuses in parallel on each batt, or one 6A fuse on each bat, or you can use one Littelfuse's smd 7A fuse on each batt.  It's your choice.

To parallel fuses, you simply solder one end of each fuse together and solder the other end of each fuse together to make a parallel set then treat it as one fuse.  If you've paralleled 2 3A fuses together, you now have a 6A fuse and with half the resistance.

[CraigHB]

It's always better to have a direct as possible connection from the battery to the controller board, but there shouldn't be a big consideration in that respect for the charging board.

Putting anything inline with the power supply to the controller board introduces additional resistance which is something to avoid (increases source impedance).  However, it also depends on maximal input current.  For a lower power device with smaller input currents, source impedance is less of an issue.  For high output designs, source impedance increased by splices or circuit board traces can be a significant consideration. 

Since a charger board does not output more than 1 Amp, resistance in the charging circuit is not a big consideration.  Wires can be a lighter gauge or longer without causing any issue.  So there shouldn't be an issue putting an extra connection inline with charging output.  I don't really understand why there's a problem there.

[deftones]

Thanks mamu, since I have the charging board from Evolv, I guess I should wire it to the CHG input then.

CraigHB, my problem is: I don't know anything about the differences or safety issues between different charging boards and different wiring. So I was asking the best way to do it before I do anything stupid. For example I thought foreign chargers would have less protection than the one from Evolv, and I honestly can't tell what is missing other than overcharge.

[CraigHB]

All the Li-Ion USB chargers are pretty much the same.  There's a standard set of features you find with any charger controller used to assemble these USB charger boards.  The DNA charger board is no different.  There is some variance in safety features, for example you can get them with or without a temperature monitor and some have overall charge cycle time-outs. 

Some features are common to all such as over-charge and over-current protection.  That's just something that comes with the standard Li-Ion charge profile, that is the PCM, CCM, and CVM stages the profile cycles through. 

One of the great things about Li-Ion technology compared to other rechargeable technologies is the very simplistic charging profile they use.  It's based purely on cell voltage level and programmed rate.  Other charging profiles for batteries like Lead-Acid and NiMH require more sophisticated methods of sensing the state of charge.

[fullthrown]

It's your option to use fuses or not.  With the testing I've done with them I've found how valuable they are in protecting the batts from meltdown and the circuitry from frying in cases of overcurrent, especially with reverse polarity with this boost circuitry.

I listed the part number for the fuses I used in this build in the tutorial.  Go to octopart.com, plug in the part number, and you'll find who sells that part and at what price.  You don't have to use the fuses I listed though as there are options - you can use 2x 3A fuses in parallel on each batt, or one 6A fuse on each bat, or you can use one Littelfuse's smd 7A fuse on each batt.  It's your choice.

To parallel fuses, you simply solder one end of each fuse together and solder the other end of each fuse together to make a parallel set then treat it as one fuse.  If you've paralleled 2 3A fuses together, you now have a 6A fuse and with half the resistance.

Would I have to go with a lower guage wire to handle 2 separate 6 amp fuses? If I were to go with the 2 parallel 3 amp fuses on each wire, would it matter if i used 3.2 amp fuses? (the 3.2 amp fuses are the only fuses available at my local store) Thanks for the reply!

[mamu]

Would I have to go with a lower guage wire to handle 2 separate 6 amp fuses? If I were to go with the 2 parallel 3 amp fuses on each wire, would it matter if i used 3.2 amp fuses? (the 3.2 amp fuses are the only fuses available at my local store) Thanks for the reply!

No need to go lower ga - 20ga wire is recommended.

3.2A fuses will be fine - are these PTC resettable fuses that your local store carries?

[fullthrown]

Yep, here they are:http://cablesandconnectors.com/PIX/nte16003ec.jpg 
Now how would that work though (sorry if this is an obvious question), but 3.2 X 4=12.8. If the DNA 30 board is 12 amp input, then the board would be damaged before the fuse would set at 12.8 right? I feel like i'm missing something. One other thing- why do you prefer to use fuses in parallel versus using a single fuse on each wire. Is there added protection using parallel fuses or are you just using them because they add up to the limit you want?

[Visus]

Yep, here they are:http://cablesandconnectors.com/PIX/nte16003ec.jpg 
Now how would that work though (sorry if this is an obvious question), but 3.2 X 4=12.8. If the DNA 30 board is 12 amp input, then the board would be damaged before the fuse would set at 12.8 right? I feel like i'm missing something. One other thing- why do you prefer to use fuses in parallel versus using a single fuse on each wire. Is there added protection using parallel fuses or are you just using them because they add up to the limit you want?

She answered this already up a few posts.   
Woot

This thread is full of DNA awesome.

To parallel fuses, you simply solder one end of each fuse together and solder the other end of each fuse together to make a parallel set then treat it as one fuse.  If you've paralleled 2 3A fuses together, you now have a 6A fuse and with half the resistance.

[fullthrown]

Hm, sorry but i'm still not quite getting it. With 4X 3.2 amp fuses, its above 12 amps correct? Where does the resistance come into play? Basically, around how many amps would the 4 x 3.2 parallel fuses, trip? Before 12 amps? After?

[Visus]

Hm, sorry but i'm still not quite getting it. With 4X 3.2 amp fuses, its above 12 amps correct? Where does the resistance come into play? Basically, around how many amps would the 4 x 3.2 parallel fuses, trip? Before 12 amps? After?

Seems @ 12.8 after overload so 13A --

Making connections make resistances by adding another fuse you halve that fuses data sheet resistance, measured for you already by the manufacturer rating on the fuse you purchase.

 small hose small flow of water,  big hose big flow of water;

The DNA has been tested to not like a lot of resistance feeding it,  it is noisy, stinky, and down right ugly to the mouth/input of the DNA board it wants caviar/little resistance.

Mamu, Break, others,  have found  this for us by breadboarding and running through different atomizer resistances.

So with one fuse you have a very small hose with two a bigger hose and the DNA board is getting happier.  But --  throw in some bad battery contacts and the DNA will once again complain at some atomizer resistances.. 

[fullthrown]

Ah that makes a little bit more sense haha. But my main point is what are the fuses doing, other than creating resistance, if the amp load of the fuses is higher than that of the input of the DNA..again i'm sorry for dragging this on, i have all of the necessary tools for this build, but i want to build it with as much protection/safety as i can, and i'm kind of stuck on this whole fuse thing.

[Visus]

The fuses protect the DNA board and if using dual batteries from oops reverse battery insertion.  The DNA board protects itself from shorted atomizers.  Read around the forum, theres even pictures from mamu when she tested the reverse battery and how she does it.  You can also find how it's done with a mosfet.  CraigHB taught us it would work with fuses alone..

[CraigHB]

You can use a MOSFET for reverse polarity protection if you prefer, you don't ~have~ to use a fuse or fuses.  However, the fuses do double duty, they can protect from reverse polarity ~and~ any kind of short circuit condition.  The DNA provides protection from short circuits, but fuses can act as a backup in the event the DNA is not able to handle it for some reason.  When using LiPo cells especially, it's not a bad idea to have backup short circuit protection.

You don't have to use a PTC fuse either.  You can use a fast acting fuse and holder if you have some kind of problem with PTC fuses.  Though replacing a fuse every time a fault occurs can become annoying.

BTW, don't run more than 2 fuses in parallel.  It sounds tempting to increase hold/trip currents and reduce resistance, but there's derating issues that come up when paralleling fuses.  Those issues become significant when using more than two in parallel.  There's still some derating with just two, but it's a reasonable trade-off.

[ride_bmx_mhell]

hi mamu, can i use 2x 2.5a 16v resettable fuse in dna20 both are incline in + wires thanks 
this http://ph.mouser.com/ProductDetail/Littelfuse/1812L260MR/?qs=2VFNtWizgifd79olPjpZfQ==
or this would work?
http://www.fuzetec.com.tw/pptc_fsmd2920.htm FSMD250-2920-R

[mamu]

hi mamu, can i use 2x 2.5a 16v resettable fuse in dna20 both are incline in + wires thanks 
this http://ph.mouser.com/ProductDetail/Littelfuse/1812L260MR/?qs=2VFNtWizgifd79olPjpZfQ==
or this would work?
http://www.fuzetec.com.tw/pptc_fsmd2920.htm FSMD250-2920-R

The 1st fuse you linked should be ok 2x in parallel, but the 2nd one you linked the trip time is quite high.

[oleskool]

Hello everyone. I have a DNA30  knock-off chip from China coming. This will be my first build. Although I don't think I will be able to use this box, because the chip dimensions are different if I recall correctly. I have a few questions, and just decided to put them here instead of starting a new thread.
1. Lipo vs. Dual 18650 vs. Single 18650/26650. What are the advantages/disadvantages of each?
2. I noticed in the pdf it said to run a line of super glue along the ribbon connector and board. Is this just to keep from pulling them apart, or is there some other known defect?
3. Keeping in mind this is my first build.  Would you be able to suggest a Hammond box that will work well for the configurations mentioned in#1.

Thank in advance for any help.

[CraigHB]

1. Lipo vs. Dual 18650 vs. Single 18650/26650. What are the advantages/disadvantages of each?

On single versus series, battery voltage, obviously.  Higher input voltage is better for higher power outputs, but you need a power converter than can deal with it.  Your DNA 30 knockoff will not be able to handle series cells since it does not have the type of converter required to deal with input voltages higher than output voltages.  Not for sure on that, but if it works like a real DNA30, then it can not put out voltages lower than input voltage.

On single versus parallel, it's only a matter of increasing drain limit and charge capacity.  Two parallel cells provides twice the capacity of single cell with half the losses and twice the drain limit.  For a box, two round cells in parallel makes better use of the space.

On LiPo versus round cell, aside from the shape which can be good or bad depending on the enclosure (LiPos are usually flat), the 18650s can perform better in some aspects.  The big advantage of a LiPo is efficient power delivery, less voltage loss with higher currents.  However, the latest high drain 18650s compete nicely with a LiPo in that regard and they have more charge capacity for a given volume (higher energy density).  You'll probably get the best performance with a high drain 18650, but a LiPo can can better utilize the space in box and in some cases provide better power delivery.

A lot of losses can occur with the contacts used in a round cell battery sled.  If you want to use a non-removable cell with on-board charging, a LiPo can be better since they can be soldered into place.  That provides a much better connection to the battery than a battery sled, though you can use a hobby type LiPo for series packs with a standard plug to allow removing and replacing the cell easily.

[oleskool]

Thanks Craig. I was trying to decide which to go with. Looks like the parallel 18650s is going to be my choice based on what you just said.
Now to find the best box for this build.

[Claviger]

I'll second Craigs comments on the newer 18650s. Very good batteries when compared to LiPO rectangular cells.  The LiPOs of course can achieve crazy high discharge rates, their main advantage, but really we don't need 60c batteries lol.

I have found both work very well, are similarly priced, and really space vs capacity vs shape should be the main concerns imho.

[CraigHB]

The small 20C or 10C flat cells are good for an e-cig, but they don't really offer any advantage over the quality high drain 18650s other than the physical characteristics.  They fit in a box better and they're easy to hard-wire. 

The 60C hobby LiPos are not really practical for an e-cig.  The series packs can be handy for step-down stuff, but then the high drain is even less of a help.  Series cells halve the drain compared to single making that high drain limit pretty redundant. 

One other issue with those really high C LiPos is they're pretty volatile.  If you puncture one they pretty much explode.  The lower C ones don't do that, they still burn pretty fast, but it's not as volatile.  The 18650s are much safer batteries in general.