View Full Version : Hacking the Dnano charger

2009.04.01, 08:08 AM

I'm considering the fact of "hacking" my dnano charger (and perhaps also the blade mCX one) as it uses too much fresh batteries to work.

So, here's the question, what kind of transformer can I use?
(don't know if it's the correct word in english, but I mean here a power supply like the one used to charge a cellphone, or use a portable CD player without battery)
From what I know, I understand that a transformer provide only the current required by the device that is connected. So a transfo of 500mAh for example, provide up to 500mAh, but can also provide a device that requires 350mAh.

A simple tranfo of 6V with 150mAh output could it be enough to charge the battery of the Dnano and Blade wich are respectively 130mAh and 110mAh for 3.7V?
Or should I look for one that is 130 or 110 mAh?

Or, do I even need to find a more powerful transformer to obtain the same intensity as that obtained by the 4 batteries?
(In order to avoid the double red/green LED signal that means that the batteries in the charger are low)

At first my goal is to continue to use the system LED indication of each of the two chargers, but only by using a transformer instead of 4 batteries...

Thanks a lot for your help.

2009.04.01, 03:14 PM
Here (http://www.wattflyer.com/forums/showthread.php?t=42193) is the first of many hacks that come up on google for the MCX charger. Same thing for the Losi Micro series charger. May be some good stuff you can use...

2009.04.01, 04:10 PM

Thanks for this link. In fact, I do not have a professionnal charger. Only a MAHA C-9000 for the mini-z.

And so, I'm looking into a way to continue using the original charger. ;)

2009.04.01, 07:54 PM
it uses 8 batteries right? so thats 1.5v X 8 = 12V. so just find a 12 volt A/C to D/C adapter and solder it to the battery connectors. Yeah the current draw is determined by the battery charger so mah doesn't matter as long as its not to low. I don't think that little battery takes much current, i'm sure a 500mah(.5 A) dc adapter is safe.

2009.04.02, 03:05 AM

Both chargers (mCX and Dnano) use 4 AA cells. So, 6V.
In my mind I would put a DC plug on the chargers soldered to the cell pot and so, beeing able to use the charger with both battery and adapter. And if it's possible, the same adapter on both chargers.

So, the cheapest way of all! :D

Does anyone have done this before? Ideally for one of those charger, but another model is also a help. I'm not a pro in electric device and so, I prefer to go with caution before mod my chargers.

2009.04.10, 02:42 AM

I know have the answer. A 300mAh is not enough for both charger.

I went to a 1000mAh (1400 at 6v) and this works perfectly.

I will put some pics soon.

2009.04.21, 09:22 AM
And here are the pics of the modification of the Dnano charger:
http://img27.imageshack.us/img27/3466/spa0103.jpg (http://img27.imageshack.us/my.php?image=spa0103.jpg)

http://img27.imageshack.us/img27/3835/spa0102uxf.jpg (http://img27.imageshack.us/my.php?image=spa0102uxf.jpg)

http://img27.imageshack.us/img27/6232/spa0101f.jpg (http://img27.imageshack.us/my.php?image=spa0101f.jpg)

Works really nicely and don't destroy the Dnano charger.

2009.04.21, 12:50 PM
what are you using as a power source?

i like this discussion as i to do not have a hobby class charger. i simply want to use a plug in power source vs. batteries.

i have my powered pit box with 3v, 5v and 12v power outs made from an old pc psu.

2009.04.21, 03:42 PM
Thanks a lot Pierrot le Fou.;)

2009.04.22, 05:34 AM
Hello Arch!

I use a simple regulated universal voltage adapter.
This one can get output voltage from 1.5 to 12V. with 1000mA at 12V (1400 at 6V).
It also contain different plugs.

You should be able to find something similar in any electronic shop.
The whole modification (for the two chargers including wire, plug and adapter) cost me around 15€ and about one hour with my dremel and a pretty pranky solderer.

And the big advantage of this hack is the fact that I still can use cells if I need to. So, adapter at home and club and cells if I have to move somewhere else where I can't use my adapter.

@ kalou: I got trapped! ;)

2009.04.22, 01:24 PM
do you have a part number for the regulated universal voltage adapter? i can then try to find something similar.

would this work?
6V/1800mA AC-to-DC Power Adapter (http://www.radioshack.com/product/index.jsp?productId=2049709&tab=techSpecs)
Model: 273-1763 | Catalog #: 273-1763

Power your portable devices with this convenient AC-to-DC adapter. Works with devices requiring 6V and a current of up to 1800mA. Perfect for many digital cameras, mini USB hubs and CD-ROMs.

Power Device Fits Univeral Adaptaplug devices like digital cameras, mini USB hubs and CD-ROMs.
Voltage Required AC 110/120 V (60 Hz)
Power Type Mini AC to DC power adapter
Intended Device Type Products requiring 6VDC/1800mA
single voltage Yes
Power Voltage DC 6 V (1800 mA)

2009.04.22, 01:32 PM
Say guys, what voltage of lipo does nano need? Can we homebrew out own, higher cap battery? Can we mod the stock charger to charge custom ones safely?

2009.04.23, 03:42 AM
Hello Arch.

I would say that the one you founded will be perfect. In fact, I do believe something around 600-700mAh will be enough. It just need to give as much power as brand new AA cells.

I started with a 300mAh but it wasn't powerfull enough as the led light on the charger was dual red/green. So I decided to go 1000 and not beeing annoyed anymore. The charger will only use the power it needs so the adapter doesn't force to give less than it's maximum capacity.

The one I use is a HQ power PSU10R. Some obscur "made in china" brand... At least for me. :p
I get this as one day I had to replace an adapter for my computer's speakers and get one of this brand. It runs perfect since 3 years now and so I hope to get the same with my new one.

I know some guys get their own lipo for the Dnano but if I remember correctly, it is a higher capacity that is used. The voltage is 3.7 as any 1 cell lipo. If you can get the lipo to fit in the charger, I believe it should not be a problem to get it charged. But for my Dnano, I prefer keep on the kyosho stock lipo at the moment.

2009.04.23, 08:58 AM
3.7, you don't say... :D :D :D This technically means I can just pull 1 outta my motorola and viola- fairly light, 800 or so mAh with its own control board. Sounds prospective, doesn't it? I've always wanted to utilize those in RCs, but voltage was too low for something like Zs. Now the idea seems perfect.

Plus they're 5-10$ to buy and usually come with USB chargers for them, so screw kyosho's $50+.

2009.04.29, 09:33 PM
well, 4aa = 6 volts. mah is pointless to worry about unless you stay above a min. which you seem to have figured out as aa mah ratings are usually 1000-2500 mah.

i just want to make sure i'm not going to fry a brand new charger and or battery. at $21, the batteries are not cheap. i thought ahead and bought an extra and plan to for each car i buy.

i really don't even plan on using the charger wit batteries. i seriously do not want to have to buy batteries to charge batteries and don't want the hassle of charging charger batteries.

i'd also love to be able to use my 12v power jacks in my travel psu box so that would require some sort of step down from 12v, ?mah to 6v, 1800mah.

2009.05.03, 02:36 PM
checking into this converter more, it uses a rs adapater piece that precludes using a port. it would essentially be a dongle hanging out of the charger that you plug the converter into. either that or hardwire the converter to the charger. i prefer the jack style plug but debating on if i want yet more parts to solder/assemble, etc.

can you please tell me what jack you installed in the charger?

2009.05.04, 03:58 AM

It's a normal 2mm DC jack if I remember correctly. The adapter I use come with various jack so I could have chosen other plug/jack.

I simply find more convenient to use this type of jack and plug as it's the model used by a wide variety of electrical device such as CD player, PC speakers...

I've seen other plug used successfully by other guys. So, just check what you find the most clean/easy for you.

By the way, no problems at all on both my mCX or Dnano since I made the hack. I even got another Dnanocharger at home that I must hack for one man at the club.