Lipo 3S

[pappyboy]

Guys,

Noob here. I've done some searching and can't find the answer I'm looking for so I apologise if it is answered somewhere else. I've got a small 1300Mah lipo battery that I'd like to use for my 9X. I've got a smartieparts board and have uploaded the er9x firmware. Is it as simple as cutting the plug off the battery holder that comes with the Tx and soldering it to the positive and negative cables of the lipo? Will a 3S lipo provide too much power for the radio and is there a risk a 3S would fry it?

I have seen the thread on the LiFe battery, but can't get one at the mo.

If others have used 3S lipos, is there a trick to setting up the alarm/calibration issues with the radio, and if so, can you provide some details on what I should use or look out for please?

Thank you

Darren

[Crucial]

3S lipo will be fine. There are many using a 3S without problems. If it were my radio I would set the voltage beeper to go off at 11.3V. This would be around 3.75 for each cell. To calibrate the voltage in the radio I plug in the battery and turn the radio on. Then I test the voltage at the battery and set the battery voltage in the DIAG screen in the radio settings.

[ShowMaster]

Please be very careful and not reverse the battery polarity. It will smoke your radio real fast.
Many have.
SM

[pappyboy]

Please be very careful and not reverse the battery polarity. It will smoke your radio real fast.
Many have.
SM

Thanks Guys. So ShowMaster, I simply join red to red and black to black right??

Thanks again guys.

Darren

[pappyboy]

3S lipo will be fine. There are many using a 3S without problems. If it were my radio I would set the voltage beeper to go off at 11.3V. This would be around 3.75 for each cell. To calibrate the voltage in the radio I plug in the battery and turn the radio on. Then I test the voltage at the battery and set the battery voltage in the DIAG screen in the radio settings.

Crucial,

Thanks for the info. Not sure if I understand. How do you test the voltage at the battery if you've got it plugged into the radio with the radio turned on. I'm reading your message that you plug it in and turn it on, then test the voltage with a meter of some kind, then plug it back into the radio a d set the voltage in the DIAG screen, but I think I'm misunderstanding what you're saying.

By the way, I forgot to mention that the battery has a 30c discharge rate. Is that still OK?

Thanks again. I really appreciate your help.

Darren

[ReSt]

So ShowMaster, I simply join red to red and black to black right??

Darren

NO, verify the polarity and don't trust the colors.
join +to + and - to -

Reinhard

[gohsthb]

If you can measure the battery voltage while it is plugged in to the radio you will get the best calibration. You can probably set your battery alarm down to 10.5V The nominal voltage of a 3S is 11.1V. You can run a lipo as low as 3V/cell so 9V on a 3S. However the lower the voltage goes the faster it drops off. The discharge rate of a lipo is only a measure of how fast you can get the power out of it. And yes beware of reversing the polarity of the battery. There is no internal protection on the 9x.
-Gohst

[ShowMaster]

If your lipo has a balance connector like most you can measure the plugged in pack but putting your meter across the the two end pins from each edge, carefully so you don't short the pack! This voltage will be the same as he larger+ and - wire reading. Another way is to stick a modelers or sewing pin thru the larger wires insolation red and black at two locations that won't allow a short at use you meter there. A small pinhole will not cause any future trouble when you remove the pins but may prevent shorting if you try and use the large meter probes on the back of the battery connector ect. Helps to plan ahead on how your going to do this, even buy a balance port male connector, before you power it all up and measure. Sparks can fly if there is an oops probe slip. Again, even after you solder the new tx connector on please measure the voltage polarity before you plug it in and power on your 9x.
SM

[gohsthb]

Yes sparks could fly. You 30C lipo can put out over 40 Amps!!

-Gohst

[pappyboy]

So ShowMaster, I simply join red to red and black to black right??

Darren

NO, verify the polarity and don't trust the colors.
join +to + and - to -

Reinhard

Reinhard and others,

Thanks for the helpful comments. OK. So I know which of the battery wires are positive and negative (red and black respectively), but how do you mix up the positive and negative on the battery pack plug on the stock battery holder if you're using it to solder to the batt cables. Shouldn't the black wire on the stock battery holder go to negative in the radio and red to positive? I'm not sure I understand how people are getting this mixed up and frying their radios unless the factory black and red wires in the stock battery holder are sometimes installed the wrong way around. I'm not trying to be clever, just want to understand before I try the mod. I'd be very grateful for any advice here please.

Thank you

Darren

[MikeB]

Because there is no protection if the battery is connected the wrong way round, and components get destroyed if it is, you are just being advised to be absolutely sure you have the power connections the right way round. We don't want you to break the radio! You never know, I have heard of LiPos having the wrong wiring where the black wire is positive and the red negative due to an error in production. If you can check everything then it is worth the extra time taken.

Mike.

[pappyboy]

Hey Mike,

Thank you. That makes sense. As I said, I'm new to this and didn't know that about batteries. Thanks for the quick response.

Darren

[skywalker14]

Can you just Solder Pos And Neg Wire On to Circuit Board and Run It Through Where USB programmer usually is routed through With Whatever Connector You Choose For Example Deans and eliminating Factory Wires With Say 14G Wires?

[MikeB]

The USB programmer is only 5 volts, you must make sure the battery goes through the power switch and the 5 volt regulator.

Mike.

[kaos]

I agree with ghosthb said, if you use a 3S lipo you can set the alarm at 10.5 V. lipo will get damaged only if each cell gets below 3.2V. but like Mikeb said, when it gets to lower votage, the voltage drops fast. so set it at 3.5V /cell (10.5) will be a safe bet.

When you can get a LiFe (now is in stock at HK): http://www.hobbyking.com/hobbyking/stor ... duct=15088
then you set the alarm at 8.6 to 8.7 volt. cause the damaging low voltage for LiFe is 2.8 v /cell. LiFe is much better than Lipo, I have to say, the discharge curve is much flatter and not a fire hazard like lipo. shelf life is longer than lipo too. I can set that LiFe in the Tx 6 month still not much change in voltage. I have only tested it for 3 months sitting there in the Tx (I still want to fly, you know ). There is not one bit drop of voltage.

that HK LiFe comes with a futaba plug, it is very easy to attach a servo connector to the Tx plug (not even soldering), put a female servo connector by clamping 2 in the connector. You never have to worry about getting the polarity wrong. as long as you connect the middle wire as positve wire corretly the 1st time. If by accident you can force the servo connector the wrong way in, it just won't have any power. (you do need to trim off the little fin along the futaba connector that came with the LiFe, but it only takes 3 sec with a sharp blade).
I don't need to fiddle around unplug the dingy connector 'inside' the Tx any more, just unplug the converted servo connector and done.

like this:

[kaos]

by the way, I found out the PS2 connector fits perfectly in the original charge plug hole. I got 2 pairs of PS2 connectors ordered, when I get around to do it, I will replace/desolder the stock charging connector with a PS2 plug at that position and connect the 3S battery balancing plug (4 leads) and the extra power lead (2 leads) to the 6 pin PS2 connector. And I don't even have to open up my Tx anymore for balance charging. Any one has quick fingers can do this earlier than me too.
Another mod you/I like to do is make a little hole on the side to place that Smartie USB port to the side. I am tired of opening up my batt cover to reflash/update er9X or change my splash screen every time I need to do it. Especially, these geeks around here come out with new ideas/functions/ improvements like every other day. My batt door is wearing out and turning loose already.

[Crashj007]

kaos, I just obtained the parts to do that. One source is http://www.lcom.com . They make a front mount mini din, MD66FJF. They also make a great cable and if you get a double ended male-male you have two cables for $7US PN CSMD6MM-6.
Mouser and Digikey carry less expensive all plastic receptacles. The digikey PN is CP-2960-ND
If you replace the built in transmitter antenna you can run the USB connection up there and protect it with one of the rubber bolt cars from Lowe's.

[kaos]

1.90 per connector set , 2 is 3.80
http://www.ebay.com/itm/130610982802?ss ... 1439.l2649

but you have to do some work to dig that little connector from the rubber housing though and it is tough housing I must say. already pulled on out.

it has 6 poles/pins , but the ps2 cable actually only has 4 wires in it.

[Crashj007]

You pays your money and you takes your chances. The cable and connector I cited are full 6 circuits. There is probably some sort of minimum order, of course. Digikey also has the plugs for you to wire up yourself.

[kaos]

Hmm, just looked into those plugs you showed. a set would be 12-13 dollars. well, I will get a few blister on my fingers trying to solder those wires to it, I guess.

[Crashj007]

Yes, I do get the point. OTOH, mine are free.
"I'm so ashamed . . ."

[Crucial]

http://search.digikey.com/scripts/DkSea ... D&x=6&y=15

I used these for putting a programmer plug in the radio. A little drilling to widen the charge jack hole and some CA glue to hold it in and it fit's perfectly.

[kaos]

yep, they all work. Just finished soldering one female connector for the Tx. Got to say, takes a long time, for me, to get all six wires soldered. Now need to solder the male one for charging cable. no blister though.
But it is a good practice for me to practice small soldering. getting quicker and quicker.
and all done by a DIY copper soldering tip too. Well, this is part of the fun into this hobby.

Cruicial: do you have problem fixing that connector in the tx in place? I found the PS2 is quite tight. I noticed pushing and pulling take a lot of pressrue and force. I wonder how good the fixation inside the Tx would work without a flat extension fin to stop it from being pushed in or pulled out, with just epoxy or hot glue.

[Crucial]

I have only broke the CA glue bond once. It was within the first few uses so it was a poor glue job. I haven't had a problem since.

[cre8tiveleo]

So off topic...

[Crashj007]

I have attached a 6 position mini-din for the battery charging on the back. I did take pictures and will post when the battery is connected. Since I already installed the SP board and USB, I'll leave it like that, but another mini din would be a good way to handle the programming interface.

[kaos]

So off topic...

OK, continue on to the proper topic here: viewtopic.php?f=25&t=25