2S batteries - what do you want?

What’s up guys - long time lurker here :wink:

Im considering to extend my partnership with mylipo and start distributing 2S lipos in AU and US. My own experience with micro brushless quads and their battery requirements is very limited, but Im getting hammered with requests for them.

Considering my current project list, building a few of them would delay things probably for months, so let me ask you instead:

What 2S batteries do you want?

  • size
  • weight
  • wire length
  • plug
    ( you can enter wishes for capacity, but we will probably just maximise discharge rating based on size/weight, so capacity will be a natural consequence)

Participation in this thread might be rewarded with early access at exclusive prices to whatever we come up with :wink:

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I hate to answer a question with a question but will the 08-20-18’s handle 2S?
If so then 480/500, standard wire length, 50mm
Is xt30 a good choice here?
I’m guessing it would weigh just over 18g
I’ve really been enjoying the 1S HiLV packs too would that be possible in 2S?

Same or close weight, double the available current. Yes?

0820-18s will blow up very quickly at 2S.
Even feeding them 4V continuously will kill them quickly. The -18s only survive because the batteries we run them on sag low enough and we only use full throttle momentarily. If you would connect a fresh 480mAh directly to a single 0820-18 with a Parrot prop on, it will get very hot very quickly. Its fun though. I should make a video of it, so you dont have to waste a motor :wink:

The main reason to go 2S is that its very hard to make brushless motors with such high Kv ratings as we can make coreless motors. So we need more voltage to get to more performance.

Along with my endeavours into 2S batteries goes the first production batch of “2S” 0820 motors:

There is nothing special about this motor that makes it “2S capable”, its literally just dropping the speed until it doesnt blow up anymore within 5-10 minutes of full throttle.

In my experience with 2s brushed - around 20 grams seems to be the sweet spot. Any heavier and you have a fast quad that carries too much momentum into maneuvers and can’t bite with anything less than 65mm props. Most 2s motors overheat on these blades with the higher weights too and die fast. This was my experience with the 7v rated 52k rpm.

I also tested the 3.2v rated 29500 rpm. (Unofficial 2s insane?!??!) Had power like a brushless quad even on 55mm props and 30g batteries - but died very young. Total meltdown. Physical construction can’t handle the rpm or current.

I have yet to build brushless (parts in transit) - but also expect weight to be the number 1 priority.

As for power lead - I’m going to experiment with just using the balance lead for power supply to shave even more weight. So I’ll probably open and Un - solder whatever else they come with.

For size - I’ll take whatever you can cram into 20 gram packs. :slight_smile:

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And thanks for checking in with us! Yet another reason to support MMW!

I have been using the 285 and 333mah myLipo batteries that have an integrated JST-XH (balance plug) connector. I can charge them by just slotting them into my parallel charging board balance connectors. Onnthe quad I use balance plug connectors soldered to silicone wires. Someday I will design a quad around the plug and make it frame mounted.

I came to that design because I trust myLipo batteries and those were a good size and on sale. I wish I had more. It’s very convenient and works well/cheap/light weight

333mah is the better size. I run 1103 8000kV with GemFan 3025s cut to 50mm. 3min of intense flying. Have some 1102 10000kV motors on the way. I’m looking forward to them. @las likes them.

2 Likes

Thanks a lot for your for your input Travis!
To me, it makes sense to ask my audience first, even if I give away my intents to potential competitors.

20g seems like a good target weight for 0820 direct drive on 2S.
If we can squeeze enough current out, maybe the same pack works for the smallest brushless builds too.

I bet thats pretty close to 20g :wink:

Should scream just right at 2S…

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ROTFL, @Benedikt! :joy: We do miss seeing you around here!

I’ve accumulated too many LiPos right now, so don’t want to suggest anything that will make me buy more. However, a high-C 2S 350mAh at 20g does sound good! :wink:

2S 350mAh is a size I have yet to explore, as my smallest packs are 2S 450mAh currently. I think that a 2S 350mAh pack could be a good lightweight option for my @Ian444 105mm frame with RX1102 7800KV motors.

I think on such a small pack I’d want a JST-RCY connector. Even though I currently use and like XT30 for micro brushless, that’s probably too much extra weight.

I vote for 350-400mah. Minimum 40C. HV would be nice. 20-25g weight target.
Also think red JSTs are fine 'cause it’s no problem to change to xt30s if wanted.
Form factor: as small as possible.
Love those tiny 350mah mylipo but more than 25C would be nice.

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I’m currently using Mylipo 350mah 35-70C (with red JST) for my new micro brushless build, but I’m having some issues with voltage drop. On full throttle I quickly hit critical voltage, up to the point my VTX shuts down and random motors start to fail. At first it was only when punching at the end of a battery, but it’s getting out of hand right now. Dropping out of the sky regularly. I hear the ESC startup tone right after. That combined with the critical voltage warnings of the beeper and losing video makes me think it’s a voltage issue and not ESC desync.

I’m thinking the battery might not be able to handle the amp draw of the 1103 10000kv motors. Maybe not enough C rating? I’m getting 3 minute flight times and it comes down at 3.7, but voltage drops very low under heavy load.

Maybe I’ll try redo my solder joints in case there is some issue there. Yesterday I made an adapter to connect 2 of my Graphene 600’s in serial to create one big 2S 600 lipo with high C rating, to see it that helps. But yesterday I couldn’t reproduce the problem whilst holding the quad in my hand with props on giving full throttle, even with the 350 batteries… It’s a weird problem. (not fun)

Don’t mean to turn this into a troubleshooting thread, but given the fact I’m struggling with my battery choice for 2s brushless I figured it would throw it in here…

I have been using 2S mylipo packs for a while now. While I can understand the choices the others like, I mainly use 400 mAh 40C/80C and 480 mAh 40C/80C. My setups tend to be a bit power hungry and with a lower capacity / C-rating I just would be buying new batteries every week. Seems the 400 mAh mylipo packs I use are not available anymore.

They do. Ohh and of course XT30U please as long there’s no better alternative. I would really love something more lightweight than the 400mAh/480mAh packs, but I think we then need something with a better real C rating :wink:

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I’m using some mylipo 350mAh 2s along with 300mAh nanotech 2s and they both give 4 minute flights on 1103 6500kv. The nanotechs however perform better through the whole charge where the mylipo triggers the buzzer on punches after only 1 minute, the nanotech is fine until almost 3 minutes in. High C at 350/400mAh would be sweet for me.

I agree 100% with that. Maybe a slightly bigger range 18gm to 30gm, 2 or maybe even 3 choices would be good to fine tune the quad for performance and flight time.

I like your idea @Denovich just using the balance connector to power the quad, I’ve been thinking of doing that lately, there are too many wires hanging out in the breeze compromising performance.

The JST-RCY seems to work OK at this size. I just bought two 300mAh 45-90C Nano-techs from HK to give a choice other than my 450mAh Nano’s and a 2x480mAh mylipo’s wired up as a 2S battery. I tried 2 x 260mAh 1S Nano’s and they seemed to do OK, but they are old and flight time was too short. From memory the 300mAh Nano’s might be down on power compared to 450’s, we’ll see. All my 2S are getting old, I need a whole new set again.

Regarding connectors - I did this to my 400mAh cells, since they only came with balance plug.

XT30(U) for main power / one pin dupont connector for balancing + a small wire harness to balance charge them.

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I back you both; using the balance plug is a neat solution too (reminds me of the old RC Logger eox) also my 2 cents worth is the lighter the better, so if I could get a 15g 2S high C pack I’d be happy. Overall flight time is not as critical to me as the burst current capability

I avoid red JSTs where I can since I’m using XT30 (where the XT30U feels much better than the standard XT30).

You might ask yourself why I’m mentioning XT30U:
XT30U feel connection wise more like “real” XT60, very solid connection compared to the XT30s I have (all of my XT30/XT30U claim to be from AMASS ®). XT30U and XT30 are compatible and the connector that gives the more solid connection is the one on the quad side, so it doesn’t really matter whether it’s XT30 or XT30U on the battery. The XT30U and XT30 I have are almost the same weight, while the XT30U is a bit shorter - length wise.

Back to “why red JSTs suck”: Super inconvenient to unplug (seriously, no comparison to XT30 / XT60 - these connectors play in a different league); sometimes bad crimping & breaking wires; not the best current capability. Something like a XT15 or a XT20 would be really nice to have.

While we are at it - what wire gauge? Is 22 AWG enough? I think that’s what I’m using on my current 2S builds.

Didn’t the 480mah mylipo 1s that performed so well for us have 18ga? After experiencing the punch of that battery - I have kept all my leads on 8.5mm builds on matching 18ga. Could be overkill though as shortening those wires is always #1 on my weight reduction revisions of my builds.

Watching and waiting to see what you guys come up with. And like everyone else I would say 300 to 500, hi C rating and as light as posible, I myself still use JST, true its not the greatest but thats what all my builds have, XT30 would give you the option of 2S or 3S with not much hassle, but like I said I would prefer JST.

I find them really easy to plug in backwards if you’re not paying attention and you’re a bit hamfisted.

Any updates on 2S batteries?

I could use a few more.