Cases A new charger build

murankar

Staff member
Yes its playing okay I guess. Its finding the correct stuff for the build that's been hard for me.

As for ends:
On the awg8 and 10 I was thinking crimp on ring ends. These will allow for easy maintenance from inside the psu. Also thought of the 4 or 5 mm bullets for the opposites side of the wires. That power block is what I have been thinking of using. That will allow me to expand or configure output power without messing with the PSU. I was hoping to find something that would allow 4 outputs. I have to be able to jump from the block of one PSU to the block of another so I can make 24v 1050w at 47amps.

The pl6 also has ec style connectors. This is good and bad. The bad is that it introduces a fail point in the power system. If I have a fail point I want it to be a fuse not a connector. The good is that it is an ec style connector, firm solid connection that's hard to separate.

Wires:
I think an awg8 line would suite for the jumper that is used to make 24v. Awg10 line would be used for everything else.

I think 10 would work for the jumper because tony did his with 10 and charged a shloald of packs at 30amps just fine. 4 3s packs maxed won't even challenge the system at all.

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vimy

Member
Hello M,

The EC5 connector won't be a point of failure, it has a 120 Amp continuous capacity. The only reason an EC5 would fail is through faulty soldering creating a dry joint.

What would be an idea though, is using breakers rather than fuses so they can be reset, either thermal or manual. These can go inline from the brass terminal blocks then an EC5 connector for the charger to connect to. Something like this:

http://thumbs2.ebaystatic.com/d/l225/m/m7_iRH6l4vZfBsMoot2dOUQ.jpg

To save money on cable, I went around to a car wreckers and stripped out what looks to be 8AWG from various 1990's Volvos. You get good lengths of cable out of them and some of it is in black removable outer covering so it still looks new. Strange thing though, the red cable seems to have a sticky coating and numerous attempts to get rid of it has failed. =/ ??

Thinking about what you said, bullet connectors would be a good idea for the ends of the internal wiring. Since it is not going to move and flex, soldering it isn't a problem.

I use "Images" a lot on the browser to find components. It seems to be the best thing for finding difficult to locate parts.

The charger is coming along OK. :)
 

murankar

Staff member
Thats what I have been doing alo. I have been trolling forums to find images of similar builds to get some ideas on how to do this one.

My dad and I were looking at copper flat stock and a few other bits and bobs. One thing we discussed is the type of wire I should use. In his experience of 39 years he told me that AC current prefers stranded wire whereas DC prefers solid core wire, so now I need to do some research. Down side to solid core is how stiff it will be so I just might stick with stranded for both sides but I will still look into it.

Ill look at the breaker idea also. So right now I am at a design standstill till I get more info.
 

Tony

Staff member
Actually, I think that is backwards. All houses are wired with solid, and all cars are done with multi-strand. In my charger, as well as with Gaba's build, we both used Deans Spaghetti wire (I think that's what it's called anyway). Very flexible, and very durable for prolonged use. And with hundreds of strands of wire in there, it works quite well. Much better than thick copper. Each of these strands is silver coated copper, and silver conducts electricity better than copper.
 

vimy

Member
M, I've never seen a 12V car system use anything other than multi-strand cable. Due to constant vibration, a solid cable would fracture due to it's stiffness.

Solid cable is not suitable for those terminal blocks either.

The only time I have seen solid cable used, is for domestic 240v power in homes.
 

murankar

Staff member
its possible i got it backwards. I have a bad habit of reversing info like this. more studying is in store for me. I have a few decent lengths of AWG10 wire in the garage that I bought for a power inverter. It has multiple strands of copper. The wire was meant for a car stereo amplifier. Not sure if this would be good wire to use.
 

Tony

Staff member
It will work, it's just a little harder to solder than the wire that I used. Amp wire is still quite flexible.
 

vimy

Member
The ideal way to solder heavy multistrand cable is to use a crucible of molten solder and dip the flux soaked end into that.

The other way is to use a large iron so heat isn't easily lost. Hang the cable with the end downward and heat with the iron. Introduce the solder and let if flow over the bared end. Hanging it like this, goes some way to stopping the solder wicking through the cable which is undesirable.

What ever you do, do not use acid based flux.
 

murankar

Staff member
Is this what you ment--- Deans Wet Noodle 12 Gauge Wire


The biggest I found so far is 12g I would really like to get to 10g if possible. I am beginning to thing 10g will work for the entire project on the output side. I don't thing I will be able to solder the wire with the solder irons that I have. I only have 40w irons and one of them is adjustable temp but maxes out at 40w. So I am going to consider using crimp on loop ends. I am also thinking of not doing the bus bar, just use wire to jump maybe two extra 12v posts on maybe have one external 24v even though at this time I don't think I'll need it. One extra I am considering is a 5v usb plug in. This could come in handy for my scorpion power stations and my cell phone since it drinks power like mad. If I go to fly and video my phone would be dead in about an hour so having that option could be beneficial.
 

Tony

Staff member
I tried to find where Gaba and I ordered our supplies, and I can't find any of the links.
 

murankar

Staff member
I have found a number of sites selling it. The only size I could find is AWG12. Is that going to be big enough for a max load of 47 amps? I am guessing if that's what you used it should be fine since you had a shload of packs at 30 amps.
 

murankar

Staff member
Those were going to be my alternative in case I could not find anything that would work. I think I might be ordering those just so I can end the search. I think 5 feet of each should be plenty with some left over.

As for the case I think the 120sr maybe getting evicted for this project. So now I have to find that case and start taking measurements for the deck and set the PSUs inside.
 

Tony

Staff member
Those are a meter a piece (3'). I'm not sure if they cut them or not so if you order two, you may be getting two 3' pieces, or a single 6' piece. My bet is 3' though. But yeah, I would order those.
 

murankar

Staff member
I am thinking it will be two 1 meter pieces, but then again its possible they could send it in one piece. I will have to inquire about it.
 

vimy

Member
Hello M'

Do what ever is appropriate. Crimping sounds good, it keeps the cable flexible along it's entire length without risk of "wicking".

All that has to happen is a low resistance joint. That is the most important result.

As far as cable goes, I thought the input cable to the PL6 and the PL8 was 12AWG.

If you are considering another charger at some stage, it would better to put 10AWG or even 8AWG so that two chargers can work off the PSU connection.

Those brass terminal blocks take 4AWG input and four outputs of 8AWG anyway.

Make sure you have enough depth in your choice of case, so you have enough gap between the charger and power supplies. This will allow for better cooling.

Get a cardboard box of a size you are considering, so you can "mock up" a design.

I'm probably stating the bleeding obvious. :)

All the best.
 

murankar

Staff member
its going to be a long build. I still need some AWG 10 wire with ring ends, a couple switches, velcro, binding posts, acrylic and the charger which at the moment is still the PL6. I have a lot yet to get done. The hard part is finding the time and money to get the rest of the stuff.


The 120sr is officially evicted from the case. Have the PSUs in the case just sitting there.
 

vimy

Member
its going to be a long build. I still need some AWG 10 wire with ring ends, a couple switches, velcro, binding posts, acrylic and the charger which at the moment is still the PL6. I have a lot yet to get done. The hard part is finding the time and money to get the rest of the stuff.


The 120sr is officially evicted from the case. Have the PSUs in the case just sitting there.

Hello M,

Are you thinking of changing from the PL6 charger to something else? If so, what are you considering?

Is your initial choice of case, the 120sr, too small for what you want?

I know what you mean about time and money. It has taken me the best part of this year to collect all the gear I wanted to make up a well equipped ground station. And yes, M, there will be A LOT to get built, but like you, I'm up for it and looking forward to getting started.

I have a few things to do, like establishing a work area to do the PSU modifications and rebuilding the flight case I have for the charger. Still waiting on the materials supplier for that.

In the end it will be worth it, as it will add to the overall operation. You can concentrate on flying planes.

There is nothing more frustrating than poor ground support. You end up wasting more time not flying, if you have to wait for batteries to be charged because the charger is inadequate. There is also the safety factor with using good quality gear.
 

murankar

Staff member
I have the same case Tony has for his case. It a harbor freight $19 case. I am not changing the charger right now but if the option was there I would go one size up to the PL8. That charger is way more than what I need and would fill a want more than anything.

This case I bought before I left for Korea almost 4 years ago. I wanted to take the 120sr with me but know way to pack it. So I got the case and had everything in it to fly. Radio heli batteries and the eflight charger with some spares. Now the 120 needs a tail motor and batteries.

Now that i wont be traveling much I figured that the case would work for this project. Now I don't need to make or buy a case for this project. This will allow me save money and invest it else where on this project.

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