Need help with XTW6009

[BOFH]

Started work on my second mod today.

Thought id do a little boost mod based around http://www.ebay.co.uk/itm/XTW6009-DC-DC-Voltage-Boost-Module-Output-Adjustable-Power-Module-4A-e-/261479097494?pt=UK_ToysGames_RadioControlled_JN&hash=item3ce15e6496 with a pair of 850 mah batteries in parallel. 

4A limit should be ok as this one is for the wife and she mainly uses 2.2 ohm Mini Davides so don't need much power.

Ive changed over the POT to give a more sensible range.  Unloaded it works perfectly.  However when I add a load the voltage output is very low, starts around 3 ish and will slowly climb to just over 4 at most.  Unloaded I get 3.6 to 5.8 depending on where the POT is set to.  To be safe ive stuck a 2.8 ohm coil on to keep the current demand down for testing.  The batteries are not fully charged yet, 3.8v atm and drop to 3.65 under load.  Im charging now to see if that the issue but I don't think so as they are rated for far more current than this can ever pull.

Is the issue the XTW is just no good for the job or have I messed something up?  If its the XTW can someone recommend me a similar sized alternative.  Really need this one as a boost mod to keep it nice and simple and USB charging.  Next mod will be a buck converter for me

Soldering work isn't the neatest as my iron isn't holing temp properly, need to send it back on Tuesday to get sorted.

This is everything wired up, no box for it yet thought id check it works first and my printer is in bits waiting on me finishing some upgrades.

[Breaktru]

What type of batteries are you using? They maybe the problem. Also are your input and output wires heavy enough?

I'm not familiar with that board. Could also be a factor. 1st start at looking at the batteries, wire gauge and solder points for cold solder.

[BOFH]

Batteries are a pair of these in parallel  https://www.hobbyking.com/hobbyking/store/__51375__ZIPPY_850mAh_20C_single_cell_UK_Warehouse_.html

All the power wiring is https://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=46597 non power is the same type but 24 awg.

Could well be the soldering that's the issue.  Was hoping someone might know the board.

Debating buying another board as can get them for £2.80 and wiring a 18650 to one end and the 510 straight to the other and see what happens, might be quicker than stripping all the wiring down and resoldering it.

[Mimms]

The batteries seem capable and the wire gauge is good. I would suspect the soldering. Or might be that the board design is crap. Buying a new one most likely will be the same. I wouldn't expect good efficiency with that board either.

[BOFH]

Any other small boost boards around that will do the job?

Really only need about 4.2-5v(Ish), 3A, 15w that will work with a 4.2v input

Main goal of the mod is something small for the wife. 

[Breaktru]

The PTN04050C. You can get 4 free samples from TI.com
See: http://breaktru.com/smf/index.php/topic,460.0.html

[BOFH]

Thanks Breaktru ill have a look at that one.

Had a bit more of a play with this one.  The black horn switch appears to be part of my problem.  Its rated for the current but its crap.  Removed it from the circuit and im getting 4.1 under load (no creep up from a 3v start) on a 1.8 coil and 5.1 on a 2.9 coil, even if I change the resistance for a higher voltage this seems to be a hard max limit.  So im guessing now its a limit for this board.  That said I hooked the wifes Davide up quickly and its a better vape than the Vamo shes got it on at the moment so I might test this one a bit more.

Looks like I need to hook a mosfet up for the momentary switch as the black one was the only push switch ive got that can handle any current.

[CraigHB]

Boosters are generally sensitive to input impedance so the poor quality horn switch could likely cause a problem.  For any booster, you want a good low resistance connection to the battery and also a battery with a high drain limit to support the demand.

[BOFH]

Thanks for the help guys.

Dropped a mosfett in today, and has dropped the output again.  But reading some more info on mosfetts on here I don't think this one is really suitable for a single battery? http://www.mouser.com/ds/2/308/NTD4963N-114435.pdf

Im looking at this one instead http://www.mouser.com/ds/2/302/PSMN1R8-30PL-354301.pdf

The drain-source on-state resistance is only stated for 4.5V and above but the graph (fig 12) I think shows it will work down to 3V? And its a far lower resistance that the one ive got.

[CraigHB]

If you look at figure 9 on page 8 of the PSMN1R8-30PL data sheet, you'll see that part has very nice characteristics for use with a single cell.  Nice find actually.  Characteristics like those can be hard to find in a TO-220 or similar package. 

[BOFH]

The Box for the wife is built!!!

Its Purple not pink BTW....just photos as pink for some reason!


This is based on the XTW6009 from Ebay, 2 * 850 MAH lipos and built in charger, master on off, voltage display input or output.  Id have to say don't buy this board, its really not very good.  It cant deliver the 4A its rated at.  With a 1.8 ohm coil it maxes out at 4.1V, 2.7 Ohm you get 4.7V.  Which really isn't very good, however as the wife likes her protanks and the like and is used to Egos it will do the job nicely for what she needs.  This will be the only mod I build with this chip.

I think a 10A raptor with 18500's is next, would like to make something smaller.  Anyone know if the Raptor generates much heat?

[Breaktru]

Looks really great. Congrats on the build BOFH.
Too bad the board stinks. Those types of regulators do get hot but the Raptor should not.

[BOFH]

Thanks.  Was a bit worried about confining the Raptor, planning on printing a very tidy box with as much hidden out the way as possible.  Think I can squeeze a 10A Raptor between the two batteries as long as it doesn't get hot.

[Visus]

My friend has a pink cell phone he claims his was broken and his sister had one laying around,  he is a multimillionaire;   so un huh made for the wife, pics?
kidding about wifje pics, maybe   

nice build even tho issues

check out the 4050 booster,  Breaks modified mod  your next 4.2v build it will with those lipo's handle up to 7amps maybe more, IDK I am scared to find out lol...
I have rung it out,  even tho rated ~2 or so amps I use it at 24-38 watts all the time no issues one year and some change going strong..
Only works that way with high discharge batts with weaker cells it will squeal like piggy and not fire..