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Jan 07, 2019, 04:35 AM
DS JUNKY
Quote:
Originally Posted by erh7771
I've been abusing graphenes high c rated packs for nearly 2 years and have never had them come down hot,

Suggested reading of first page of this thread - https://www.rcgroups.com/forums/show...risons/page422

Joe has done some good work at basically ripping the cover off of which lipos can take

Another thing that changed my flying EDFs is telemetry, now I know where my voltages are before I land and knowledge that even the most expensive lipo packs aren't eating anywhere near their C rating at nominal DoD so ... just fly with better packs.

Got some better packs and I don't do 4 minute flights any longer, If I'm not able to fly my EDF 5 mins I don't want to fly it at all ... that's how good the batteries have gotten these days.
Yes I have read through that whole thread. I was running Dinogys which were always considered tier 1 packs especially for their weight. Granted these were the 1.0 version (blue skin) not the current 2.0 version (grey skin). But 160 amps will make any pack get a little toasty. Part of the heating is also the depth of discharge. Bottom line is pulling 25+C you just arent getting much run time and still bringing the pack down at 20% charge.
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Jan 07, 2019, 05:29 AM
Registered User
erh7771's Avatar
Quote:
Originally Posted by Z06kal
Yes I have read through that whole thread. I was running Dinogys which were always considered tier 1 packs especially for their weight. Granted these were the 1.0 version (blue skin) not the current 2.0 version (grey skin). But 160 amps will make any pack get a little toasty. Part of the heating is also the depth of discharge. Bottom line is pulling 25+C you just arent getting much run time and still bringing the pack down at 20% charge.
Hmmm, that's possibly where my positive experience with the graphenes have come from; according to Joes test with a 30+ C pull past 80% DoD they only get warm to the touch were others are hot to the touch ... even the new versions.

I will be considering the Dinogy 6 ah packs, looks like they are the best MAH to weight ... just do't know about going over 20 C with them.

There are multiple 8 - 12 ah packs that will be able to do 16 - 20c pulls and not overheat or go negative and wont make a large turbine size model too heavy.

At best my experience flying a model under dry weight has been mixed and have welcomed the extra pound or two in winds above 10 mph but have not noticed the commiserate drop in performance
Last edited by erh7771; Jan 07, 2019 at 05:42 AM.
Jan 07, 2019, 08:44 AM
Registered User
Thread OP
Cell count here was 20s with a 530kv motor.

The motor in the video below is 500kv. I no longer have that fan/motor but I do plan on buying another one and for a 21s setup. With the 28-32lb thrust range of that fan, performance wonít degrade over a flight with minimal weight gain from 3x5s packs and a single 6s pack. Stay tuned!

Quote:
Originally Posted by erh7771
NICE !!!

What was the cell count again?

Looks to be 20s, just wanted to make sure.

Also, will you be doing a test with higher cell count seeing it looks like heat dissipation was one of the issues keeping from going higher wattage?

I just looked at your ""Cat 8" Dynamax EDF (28-32lbs Thrust) vid here and at 21s with the graphenes your setup peaks out about .5 kw more than it does with this video but it the end voltage thrust nets around 28 lbs before the shut down.
Jan 07, 2019, 09:10 AM
Registered User
Thread OP

7700mah pack


Just saw this 5s/7700mah pack on the dinogy website weighing less than 1000g. This pack is actually the same weigh as my graphene 5s/6000mah packs. Price is significantly higher though for the dinogy but thatís expected at this capacity. For my next set of batteries, Iím going to try HRB 5s/8000mah 35c lipos. I donít think they will hold up as well as the graphenes but at $90/pack, itís hard to pass up.
Jan 07, 2019, 10:02 AM
Registered User
erh7771's Avatar
Quote:
Originally Posted by Par_18
Just saw this 5s/7700mah pack on the dinogy website weighing less than 1000g. This pack is actually the same weigh as my graphene 5s/6000mah packs. Price is significantly higher though for the dinogy but thatís expected at this capacity. For my next set of batteries, Iím going to try HRB 5s/8000mah 35c lipos. I donít think they will hold up as well as the graphenes but at $90/pack, itís hard to pass up.
NICE !!

Be good info if those packs can really take a 20 c pull down to 3.5 a cell.
Jan 21, 2019, 06:14 PM
Battery Puffer
The dinogy 6600s and 7700s have worked very well in every jet they have ever been in that I know of. I have many BVM customers who tell me the packs are the best, work great and there very happy. You can't compare a constant 25c or 35c pull done in a test to what you will do in an actual jet flight. If your jet pulls under 160 amps, then no sense in carrying the extra weight of the bigger packs. If your jet pulls over 160 amps then you will have a very short flight unless you use a lot of throttle management. In which case the dinogys will work here too.
Par
when your ready let me know and I will give you a discount on your first dinogy order.

Mark
Mar 08, 2019, 01:06 PM
Registered User
demetrius's Avatar
Hey Par,


Just checking in to see how your flight went or if you were able to get to her yet?
May 08, 2019, 09:39 PM
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Thread OP
Quote:
Originally Posted by demetrius
Hey Par,


Just checking in to see how your flight went or if you were able to get to her yet?
Sorry it took so long to respond. Iíve been too busy at work the last few months and also didnít have any extra funds to do anything with the project. I havenít flown the plane because I canít risk it at the airfield here. I need a good paved runway to avoid damaging the gear. Mongo is throwing the latest fan into a jet of his own but heís also stuck with lots of work but he will probably get it done well before me.

I have parts for 5 more fans coming in so Iím looking forward to building a few more soon. I have a higher kv motor that I plan to run on 18s to see how it does at the 30lb mark. I think itís easier and cheaper to attain 6s/8000 packs and it may be cheaper from that end.
May 23, 2019, 09:06 PM
BFMA #13, aka Rogue 13
mongo's Avatar
Par,
take a look at how this guy vented his boomer for a 120 mm fan...

http://www.rcuniverse.com/forum/elec...m-edf-12s.html
May 24, 2019, 06:29 PM
Registered User
Thread OP
I like the intake at the front. That is something I can incorporate to get flow right over the batteries and back towards the fan. Thanks for sharing.
May 26, 2019, 05:58 PM
Registered User
How are the Flier ESC's holding up.
May 27, 2019, 09:31 AM
Registered User
Thread OP
Quote:
Originally Posted by lazer
How are the Flier ESC's holding up.
No issues with the ones Iíve been using and abusing. I do have a cooling fan installed on both of mine though and I run both @ 10-14kw. Forced cooling though the ESC is the key with a high volume fan. I havenít experienced any thermal shutdowns since the fan and Iím running them in 95 degree humid south Texas air.
May 27, 2019, 07:46 PM
Registered User
Par I have sent you a P.M.
Jun 02, 2019, 10:20 PM
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Par sent you a new private message


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