LiPo's for the Gaui R5

[jhamel]

I understand that the max LiPo compartment dimensions are 340x46x48mm. What LiPo's would fit this heli? 6S 3300mah x2? 6S 3700mah x2? Anybody using 14S?

[Vinger]

GAce 12S 3300mAh fits perfectly, either the stick pack or two 6S packs.

[jhamel]

Is there enough clearance for larger 6S 3700mah packs?

[jhamel]

How many "passes" and flight time are you getting with the 3300mah packs? Also, what is your max collective pitch, current blades, and max head speed. I just want to get an idea of what to expect. Thanks.

[john2kx]

Vinger posted his size, Robert G is running Hyperion 3650 mAh 6S 50/99C and I'm using Pulse 3300 mah 6S 65C packs.

My motor is on for 4:00 minutes and pulls between 70-72% out of the batteries. I believe that is about 5 high speed passes, one cool down/slow down circle and a unrushed smooth landing. I'm running 13+ pitch (Rail 606) and vary my head speed from 1800 (take off and landing) to 2300 to 2800. I'm using the flight mode switch a lot to drop my HS 500 rpm when full power is not needed to conserve battery power.

Vinger touched on this in another of your posts today, but I will elaborate. If this is your first speed machine, I would not be so concerned about having the most powerful motor out there. More than likely, you have not flown over 80-90 mph with a rc heli. Any of the motors mentioned today will take you to 120-140+ mph. This is a dramatic difference compared to anything I have flown in the past 20 years.

I started off with the same questions before my kit arrived. Which bad a$$ motor to buy and knew from the start I was going 14S. After 25 or so flights, my focus has changed. On 12S, it has all the power I need right now. The only issue I have is the fun ends way too soon. 3:30 minutes is up before you know it.

Mine started life with a 200 kosmik. If I were to do it all over again, I would have used a 120 amp esc and sought out the largest 6S packs I could fit, followed by the most efficient motor available. Flight logs show majority of flight is at 30-40 amps. Full power/pitch pushes it up to about 80-85 amps.

John

[jhamel]

I wonder if the Glacier 6S 45C 3700mah packs would be sufficient for speed runs. The dimensions are 140 x 46 x 42 mm so they should fit fine, but I don't know if they if they are up to the speed task.

[john2kx]

I have a pair of those Glacier 45C 4000 packs used in my X5. If connectors were the same, I'd give this 11 month old set a workout. Surprisingly, they are same length as Pulse 3300s, only 6mm wider and 1mm taller. I'll mount them up in a spare battery tray soon and see if they actually fit. I could use another 700 mah of capacity.

[jhamel]

I look forward to your findings. Thank you.

[john2kx]

The 4000 is just a bit too wide to pass through first carbon rib. Turned pack 90 degrees and it makes contact with retract pieces and parts.

[jhamel]

OK. So you established that the Glacier 6S 45C 4000mah packs won't fit. That's is useful. Thank you.

It may be safe to assume that the Glacier 6S 45C 3300mah packs will fit.

I wonder if the Glacier 6S 45C 3700mah packs would fit?

[john2kx]

Tried another pulse laying the around the shop and this may just work. The battery will fit between carbon ribs but the gaui Velcro will not pass through. Adhesive tape could be used to wrap pack through battery tray.

[john2kx]

I wonder if the Glacier 6S 45C 3700mah packs would fit?[/QUOTE]

My money would be on these.

[john2kx]

I wonder if the Glacier 6S 45C 3700mah packs would fit?[/QUOTE]

My money would be on these.

When I switched from 2700 mah packs to 3300s, flight time increased 30 seconds, while pulling 70% out of packs. 4:00 minutes vs 3:30. You may reach 4:15 with the 3700s.

[john2kx]

Plenty of space with 3300s

[jhamel]

Thank you so much for checking.

[jhamel]

So it looks like in general 6S 3300mah pack sizes should fit fine, but 6S 3700mah packs may be a bit of a gamble.

Let's talk C rating. I understand that speed helis require a high flow of current from the LiPo's for an extended period during speed runs. So it makes sense that a 65C 6S 3300mah Pulse Ultra should be able to deliver more current (214.5A) than a 45C rated 6S 3300mah Pulse Ultra (148.5A). However, according some folks, our hobby grade LiPo's only rate at 32C on their best days and then degrade from there. Assuming that 32C is about as high as a C rating can go, It is difficult for me to determine whether the substantially more expensive 65C rated LiPo's are any better than the 45C rated counterparts.

I understand that several of you are using the 65C 6S 3300mah Pulse Ultra's for this speed heli. Has anyone successfully tried the 45C 6S Pulse Ultra's or similar lower C rated packs from other brands?

[TheKingPhisher]

I just ordered 4 x 7S 3300mAh packs from Thunder Power using the BOGO discount. Also according to Helidirect the maximum battery size is (340 x 46 x 48). The TP 7S packs are (46 X 43 X 137). The TP 6S 3850mAh packs may also fit at (47 x 44 x 137). These are the 55/100C series and should handle speed flying very well. For reference RGorham is using the Hyperion 40/80C in his R5.

[Vinger]

There are no LiPo packs with a REAL C-rating above 35, check over at rcgroups for a healthy discussion on it. I use the GensAce 45C 3300 and they work well with the Xnova 4530 motor. I do have one 65C pack and the internal resistance is the same as the 45C packs, so in reality they are the same in performance.

Battery packs will always be the bottle neck for speed flying, IF you machine can handle it. The design of the R5 does not allow insane collective and therefore it does not require high C-rating packs. Buy what you can afford and that fits and fly them. Remember to factor in the battery straps to the size of your packs as the battery system does require at least two straps to be fitted.

[jhamel]

I look forward to your findings on those 7S 3300mah packs

[jhamel]

Originally Posted by Vinger

There are no LiPo packs with a REAL C-rating above 35...I do have one 65C pack and the internal resistance is the same as the 45C packs, so in reality they are the same in performance...The design of the R5 does not allow insane collective and therefore it does not require high C-rating packs.

I understand that Dave from Progressive RC has mentioned that hobby grade LiPo's don't have effective C rating much higher than about 32. I am aware that C ratings are exaggerated. I still have the question of how to determine which of the exaggerated C ratings within the same brand and size are best suited for a particular application.

For instance, Pulse Ultra's 6S 3300mah packs come with the following C rating descriptions:
1) 35C for $82.99
2) 45C for $94.99
3) 65C for $116.99

Are they rally more like 20C, 25C and 30C? Does the 35C come back hotter than the 65C? Does the 65C give more effective cycles than the 35C?