Search found 48 matches

by mkp007
Dec 12 2016 11:08am
Forum: Motor Technology
Topic: Fliermodel ESC 22S 500A 25kW - Photos and Test Results
Replies: 9
Views: 3236

Re: Fliermodel ESC 22S 500A 25kW - Photos and Test Results

But any progress / update on the Fliermodel 500a ESC ? Not yet. It will be another month or so. It failed from a control glitch causing shoot through IMHO. It would be nice to know for sure. Was heating and high voltage a factor? It seemed to be at steay state and then it just popped. Here is a gre...
by mkp007
Dec 12 2016 10:55am
Forum: Motor Technology
Topic: Fliermodel ESC 22S 500A 25kW - Photos and Test Results
Replies: 9
Views: 3236

Re: Fliermodel ESC 22S 500A 25kW - Photos and Test Results

ecotech wrote:How much did it cost you?
$408 on aliexpress.
by mkp007
Dec 05 2016 10:56am
Forum: Battery Technology
Topic: Multistar High Capacity 6S 16000mAh
Replies: 170
Views: 33621

Re: Multistar High Capacity 6S 16000mAh

Actually, the diagrams are not exactly correct, but the pics are. It helps to remember that electricity "flows" backwards, neg. to pos. Therefore, the #1 balance lead is the first neg. associated w/ the the first cell that receives the neg. main lead and everything follows from that. Ok, so in the ...
by mkp007
Dec 05 2016 1:50am
Forum: Battery Technology
Topic: Multistar High Capacity 6S 16000mAh
Replies: 170
Views: 33621

Re: Multistar High Capacity 6S 16000mAh

I received my 10 packs 4S 16Ah multistar batteries about a week ago and have been anxious to put them to a storage charge level. They all came in at about 15.0V with each cell at 3.75V. Almost every pack had each cell withing 2mV! Out of 10 packs, none were duds. Pretty happy about that. Also, I inc...
by mkp007
Nov 21 2016 2:20am
Forum: Battery Technology
Topic: Multistar High Capacity 6S 16000mAh
Replies: 170
Views: 33621

Re: Multistar High Capacity 6S 16000mAh

Thinking of ways to charge and balance four 4S packs at once. I just purchased the 308Duo charger http://www.icharger.co.nz/manuals/308DUO.pdf and it can charge and balance two 8S packs. So I just need some adapter cables like shown below. Does anyone see a problem with doing this? https://farm6.sta...
by mkp007
Nov 20 2016 7:19pm
Forum: Battery Technology
Topic: RC LiPo vs 18650 Cell High Power Packs
Replies: 6
Views: 1112

Re: RC LiPo vs 18650 Cell High Power Packs

.....BUT.. The big disadvantage is a perception of fire risk !.. And low cycle life ! ( both arguable on sketchy info)....The choice really depends on the application........Now sit back and let the debate resume ! Much of the low cycle life posts I read were because they used the battery below 3.5...
by mkp007
Nov 20 2016 6:23pm
Forum: Battery Technology
Topic: Common pack design mistakes, how to avoid?
Replies: 253
Views: 38334

Multistar R/C Packs vs. 18650 Cells

'
This post may be of interest here: RC LiPo vs 18650 Cell High Power Packs https://endless-sphere.com/forums/viewt ... 14&t=84949

I don't want to derail this thread so please post comments there
by mkp007
Nov 20 2016 6:22pm
Forum: Battery Technology
Topic: RC LiPo vs 18650 Cell High Power Packs
Replies: 6
Views: 1112

RC LiPo vs 18650 Cell High Power Packs

' I know there is a ton of info deep in these threads about the pros and cons of building packs, and I want to specifically compare building a pack from an array of R/C LiPo packs and an array of 18650 cells. As we gather info and test results, I will update this post to summarize these pros and con...
by mkp007
Nov 20 2016 5:43pm
Forum: Battery Technology
Topic: Multistar High Capacity 6S 16000mAh
Replies: 170
Views: 33621

Re: Multistar High Capacity 6S 16000mAh

I've made a few purchases from the UK, Canada Ect. They all say the same thing, you may be charged tax by your Customs and I have never been charged tax by our customs. I am also on the West Coast USA. I just bought 10 units so we'll see. I plan on testing each one individually to see if there are ...
by mkp007
Nov 18 2016 11:18am
Forum: Battery Technology
Topic: Spot Welding Copper Strips to 18650 Battery Cells
Replies: 219
Views: 36852

Re: Spot Welding Copper Strips to 18650 Battery Cells

Finally got around to ordering the tungsten electrodes that Sunstone recommended for copper, http://sunstonewelders.com/product/resistance-tungsten/?attribute_tungsten=EL125TUNG I'll let you know how it works out. Tom Interesting shape for the electrode. Can you confirm with them the optimum shape ...
by mkp007
Nov 17 2016 6:02pm
Forum: Battery Technology
Topic: Spot Welding Copper Strips to 18650 Battery Cells
Replies: 219
Views: 36852

Re: Spot Welding Copper Strips to 18650 Battery Cells

You will find grinding Thoriated Tungsten is very toxic. If purchasing Tig tungsten eletordes to make your own, Green is pure Tungsten where other colours have other elements. It might be a good idea to find out what tungsten electrode colour / type Sunstone use for copper. Good call on the toxicit...
by mkp007
Nov 17 2016 1:03pm
Forum: Battery Technology
Topic: Common pack design mistakes, how to avoid?
Replies: 253
Views: 38334

Re: Common pack design mistakes, how to avoid?

If you plate with nickel, it may make spot welding easier due the increased resistance. 2 for 1 hopefully (corrosion resistance + weldability). just how much would that resistance increase ?? i doubt the difference in resistance through a few microns of nickel at the interface , would be significan...
by mkp007
Nov 15 2016 10:43am
Forum: Battery Technology
Topic: Common pack design mistakes, how to avoid?
Replies: 253
Views: 38334

Re: Common pack design mistakes, how to avoid?

I know you are using data from reference tables, but i am struggling to understand why a microscopic plating thickness of Nickle on the surface of a copper conductor would cause its Ampacity to be reduced by 13%...?? For sure , its Conductivity would not be affected. Can anyone explain ? Good point...
by mkp007
Nov 15 2016 10:35am
Forum: Battery Technology
Topic: Common pack design mistakes, how to avoid?
Replies: 253
Views: 38334

Re: Common pack design mistakes, how to avoid?

Plating is cool but why wouldnt you simply spray the finished assembled pack with one of the protective coatings used for electrical equipment and motors etc,..like Scotch 1601/1602. ?http://solutions.3m.co.uk/wps/portal/3M/en_GB/ElectricalMkts/ElectricalSupplies/products/sprays-coatings/insulating...
by mkp007
Nov 13 2016 1:34pm
Forum: Battery Technology
Topic: Common pack design mistakes, how to avoid?
Replies: 253
Views: 38334

Re: Common pack design mistakes, how to avoid?

.....I would then be using about 10 meters total of conductor strips... Interesting. Take a hypothetical pack of 14Sx16P. Below I created a circuit diagram of the sub-group of the sketch I made previously. The current from these four cell Ctot is then dumped into a cable. Even in this simi-ideal si...
by mkp007
Nov 13 2016 12:56am
Forum: E-Bike Technical
Topic: 420A 24S ESC by aliens
Replies: 675
Views: 90117

Re: 420A 24S ESC by aliens

Here is my thread for the Fliermodel 22S 500A 25kW ESC

https://endless-sphere.com/forums/viewt ... 30&t=84783
by mkp007
Nov 12 2016 10:44pm
Forum: Motor Technology
Topic: Fliermodel ESC 22S 500A 25kW - Photos and Test Results
Replies: 9
Views: 3236

Re: Fliermodel ESC 22S 500A 25kW - Photos and Test Results

' Since we have limited test data on these "high powered" ESC, I want compare everything we can with the Alien 24S 420A ESC and why it failed at 80V and 100A. There is so much to consider: 1) Test voltage and current 2) Fet type and quantity 3) Capacitor type and quantity 4) Cooling fans, heat sinks...
by mkp007
Nov 12 2016 6:28pm
Forum: Motor Technology
Topic: Fliermodel ESC 22S 500A 25kW - Photos and Test Results
Replies: 9
Views: 3236

Fliermodel ESC 22S 500A 25kW - Photos and Test Results

' I bought this new ESC from Fliermodel http://www.fliermodel.com/en/prc-show.asp?id=694 Mass = 1.52kg (as shown in photos below) L x W x H: 7.8" x 4.3" x 2.0" Many of you will likely want to reply that this thing is crap and will not withstand much power. And that might be so. However, please refra...
by mkp007
Nov 12 2016 3:59pm
Forum: Battery Technology
Topic: Multistar High Capacity 6S 16000mAh
Replies: 170
Views: 33621

Re: Multistar High Capacity 6S 16000mAh

So are you in Europe(profile please)? If not, why are you wasting your time w/ that sketchy site over there. It seems to me that many of the reviews are from a core of haters that have some sort of vendetta against HK. I'm in California (profile updated :wink: ). Is European HK site different? I on...
by mkp007
Nov 11 2016 2:02am
Forum: Battery Technology
Topic: Multistar High Capacity 6S 16000mAh
Replies: 170
Views: 33621

Re: Multistar High Capacity 6S 16000mAh

I would like an update on how these batteries are holding up after 50+ cycles. Anyone? The link below shows a teardown of a smaller Multistar battery. You can see the cells are flat and rectangular similar to cell phone batteries. Any thoughts on how these cells compare to 18650 in terms of durabili...
by mkp007
Nov 10 2016 2:57pm
Forum: Battery Technology
Topic: Common pack design mistakes, how to avoid?
Replies: 253
Views: 38334

Re: Common pack design mistakes, how to avoid?

I 'peeked' inside my Luna Cycle Shark battery pack. It was suggested that I link the pictures to this thread so ... https://endless-sphere.com/forums/download/file.php?id=205144 The full thread is here https://endless-sphere.com/forums/viewtopic.php?f=3&t=83817&p=1239761&e=1239761 Are those copper ...
by mkp007
Nov 10 2016 11:13am
Forum: Battery Technology
Topic: Power Source to Test ESC and Motor - Mimic a 22Sx36P Battery
Replies: 13
Views: 862

Re: Power Source to Test ESC and Motor - Mimic a 22Sx36P Bat

' I'm considering ordering 18 of those packs and configure them in 6Sx3P (packs) for 89V and 48Ah. This would get about 15min at 150A for $1,000 including shipping. Each pack will be drawing 50A which seems more reasonable. I may need to remove 2 cell off 3 packs to make is a 22S due to the limitati...
by mkp007
Nov 09 2016 7:19pm
Forum: Battery Technology
Topic: Power Source to Test ESC and Motor - Mimic a 22Sx36P Battery
Replies: 13
Views: 862

Re: Power Source to Test ESC and Motor - Mimic a 22Sx36P Bat

Quick and dirty test pack solution .. https://hobbyking.com/en_us/multistar-high-capacity-4s-16000mah-multi-rotor-lipo-pack.html 6 of those will give you 24s, 16 Ahr with 160/300 amp potential for $300 ! Double up the quantity for more run time and less voltage sag ..still only $600 Quick and easy ...
by mkp007
Nov 09 2016 5:16pm
Forum: Battery Technology
Topic: Power Source to Test ESC and Motor - Mimic a 22Sx36P Battery
Replies: 13
Views: 862

Re: Power Source to Test ESC and Motor - Mimic a 22Sx36P Bat

And at 10a/cell that GA pack will be giving closer to 70v than 90v and dramatically lower at 288a peak pack current. Have you considered renting a large genset ?? The ESC I'm testing is the newer Fliermodel 22S 500A airplane version. It is not clear to me what is limiting the voltage? For fully cha...
by mkp007
Nov 09 2016 3:33pm
Forum: Battery Technology
Topic: Power Source to Test ESC and Motor - Mimic a 22Sx36P Battery
Replies: 13
Views: 862

Re: Power Source to Test ESC and Motor - Mimic a 22Sx36P Bat

After some review, I'm coming to the conclusion that I need a bank of batteries. Trying to modify my shop electrical system to handle 30kW of power is silly. Especially for 10-30min tests. So to go the battery route, is there batteries on the market that will be cheaper to use for short term testing...