Power distribution on a heavy lift rig

[Carapau]

My rig is using 8x Axi 4120/20s that peak at 50A each ie the system could spike at up to 400A. That's quite a current! My question is this- what are people's thoughts on the distribution system? (I will be using 2x 5s 11000mAh batteries in parallel)

I have seen the PowerHungry distribution board that is rated at up to peaks of 400A so on paper this is perfect- except the price- flipping heck that is expensive.

What I am thinking at the moment is that it might be just as effective, and certainly cheaper to to solder all the wires together and create a home grown distribution system.

I have seen people using copper rings and then soldering wires/connectors onto the rings.

So, what are people's thoughts on such a distro system?

 

[Benjamin Rowland]

I can't offer much feedback on power distribution, but I noticed that you said you'll use 11,000mah batteries. If you're planning to use Maxamps batteries you should look at their 10,900mah batteries with a higher C rating.

 

[Carapau]

No need for higher C rating. At 40C and 11000, that's already an output of 440amps per battery theoretically and because I am using 2 batts in parallel I will be only pulling about 200amps max on these and only then for very short durations. The only thing I can see the 10900 batteries getting me is a slightly larger whole in the wallet for no real term gain in flight performance.

 

[BorisS]

Carpau there is a thread at RCgroups about hthe C rating of the maxamps. Where a dealer spoke out the truth and got the info from maxamps that the 40C rating is wrong.

Wait i will look for it !

Boris

 

[BorisS]

http://www.rcgroups.com/forums/showpost.php?p=23145360&postcount=1

 

[ChrisViperM]

This one would be the only one to meet your requirment: http://mikrokopter.altigator.com/index.php?main_page=more_news&news_id=245

If you can live with less (like in most cases in reality) you should look at this one: http://www.mikrokopter.us/shop/dw-pwr-dist-8-droidworx-power-distribution-board-8



Chris

 

[BorisS]

first link that chris posted is certainly suitable but the price just makes me angry. Get yourself two copper plates draw some circle and bring the design to a water jet cutter (what ever they are called) oder CNC guy . Get it cut and solder on some bullet connecters or even better direct. It will be half the price.

 

[Carapau]

Wow, that's very worrying to hear about the Maxamps and I would say against trade description law here in the UK. Thanks for the heads up on this guys, I will investigate these batteries further. When every other manufacturer states a true Xc rating they mean in the constant draw, not the peak!

 

[BorisS]

Carapau,

but it was mentioned that Maxamps can assemble 11,000 or 10,000 for you with a higher C peak and constant draw. I would write them a mail about it !

Boris

 

[shco1t]

Hi Carapau,
i use x2 maxamps 11,000 4s on my sj8 with the av200-360 (seperatley powered by x2 3s 800mah for servos and vtx) and havent had any problems yet (over 20 full flights), but i have also ordered higher c rated ones so i will compare them some time this week when they arrive. I'll post if there's any real difference.

 

[Carapau]

Thanks Boris, I have just emailed them and await their response. Ill' keep people here posted on the outcome.

 

[ross_badger]

I think for a power distribution system, it is hard to beat the simplicity and functionality of a home-made "power spider" using wires and a hot soldering iron (or 2). These really work great on my hexas!

http://www.youtube.com/watch?v=Tn2Nt3sjsI0&lr=1

 

[Jodde73]

Two flat 50mm long 8x2mm copper bars with holes in the ends to bolt them to cf or gf. High amps no cost.

 

[Carapau]

Well, Maxamps were very clear about the rating and it is indeed 40c peak. They reckon that 8c constant is what they will put out without stressing the packs too much. As for the power dist, I ordered some copper bar and soldered the wires to two pieces of this separated by a couple of pieces of acrylic. All sorted and total price of about £15. Not bad and a lot better than £250!

 

[Eggbeater]

Just a thought on the Power Hungry (money hungry) PDB or any of them that use connectors. The plate may withstand certain amperage but what is EACH bullet rated at? Typically an EC5 size would be 120a? So what are 3.5mm? Loads are rated not only for continous and peak amperage but you must also consider these factored over TIME. Being realistic, what is the amp rating of the wires supplied by the battery makers? If you ask me (no one did...ha), the weak link is the wires. Any comments?