Solved Issues with esc/motor/ battery

[Superman11497]

Hi all. Fairly new to the hobby and just built and flew the FT Simple Cub. It worked and flew great a couple days ago, but when I went to fly it today I got it in the air and the rpms suddenly dropped as if the battery was running low. Didnt have enough power to keep it up and ended up putting it down in a bank of snow. I recharged the battery to try it again, but now when I increase the throttle the motor suddenly cuts out right around half throttle. Any ideas on what could be wrong? Brand new 1800 mAH 3s Tattu battery, with a 30 A ESC and 1200 kv brushless motor. I don't see or smell any smoke from the ESC or anything when I try to run it. The battery isn't puffy or anything. All the wires seem to be fine, and all the servos seem to be working just fine. I did get some snow in it from the flight a couple days ago. Could it be water damage?

 

[FlyerInStyle]

Hi all. Fairly new to the hobby and just built and flew the FT Simple Cub. It worked and flew great a couple days ago, but when I went to fly it today I got it in the air and the rpms suddenly dropped as if the battery was running low. Didnt have enough power to keep it up and ended up putting it down in a bank of snow. I recharged the battery to try it again, but now when I increase the throttle the motor suddenly cuts out right around half throttle. Any ideas on what could be wrong? Brand new 1800 mAH 3s Tattu battery, with a 30 A ESC and 1200 kv brushless motor. I don't see or smell any smoke from the ESC or anything when I try to run it. The battery isn't puffy or anything. All the wires seem to be fine, and all the servos seem to be working just fine. I did get some snow in it from the flight a couple days ago. Could it be water damage?

what is the propeller? also, a 1800 shoudl be too heavy for the simple cub. it needs a 1300.

 

[Superman11497]

9x6 propeller. The weight on it seemed fine. It flew great a couple days ago.

 

[dap35]

9x6 propeller. The weight on it seemed fine. It flew great a couple days ago.

Checking the specs on the FT Store page lists a 8x4.5 prop. So you are probably pulling too much current for the ESC and causing it to cut out.

 

[Superman11497]

Checking the specs on the FT Store page lists a 8x4.5 prop. So you are probably pulling too much current for the ESC and causing it to cut out.

That could be it. However it still cuts out with no prop attached

 

[Ketchup]

What voltage are you charging the battery to? Lots of chargers let you change what voltage you charge to, and having it set too low could become an issue. You might see 3s lipos listed as 11.1 volts, but that is only the nominal voltage. When fully charged the battery should be at 12.6 volts, as the fully charged voltage of a lipo cell is 4.2 volts while 3.7 is the nominal voltage.

 

[Ketchup]

Also I doubt it is the ESC cutting out due to prop size since I have run larger motors and larger props on 30 amp ESCs without any issues. I run the old power pack C (Emax 2215 1100kv IIRC) with a 10 inch prop and 30 amp ESC normally. While the problem still could be the ESC I doubt the prop is too out of spec if the motor is close to the power pack B size range.

 

[Superman11497]

It seems I have found the issue. For whatever reason one of the cells in my battery pack is severely low. I think the issue lies with my charger. I'm using a cheap compact charger from hobby king and it seems that somehow it isn't charging the one cell. Is that possible? Or could there be something wrong with the battery itself?

 

[mastermalpass]

It seems I have found the issue. For whatever reason one of the cells in my battery pack is severely low. I think the issue lies with my charger. I'm using a cheap compact charger from hobby king and it seems that somehow it isn't charging the one cell. Is that possible? Or could there be something wrong with the battery itself?

Look up the iMax B6. They seem to vary in size and colour but I get the impression they are all good for taking care of batteries 2-cell to 6-cell.

I first got the blue one on the left. Used it plenty, slipped up and shorted out its 3S balance socket, tried to fix and couldn't, so got another one in orange and it's still doing well today. Neither of the two I got came with a power supply though - keep an eye on that, you may already have a compatible supply cable or you might need to order one.

This charger has been invaluable for keeping my batteries good. Mainly the 'Storage' and 'balance charge' functions. You might wanna get a quick LiPo checker as well. I have one like the one on the left. It's a good way to quickly sse what charge each cell is at.

 

[jtrops]

It's been awhile since I've been on the forum, but I would be careful with the B6. It used to be understood that there were a lot of clones out there, and that some didn't last very long. So, it's a good design that can be a good deal if you get it from a reputable supplier.

If you get the Turnigy versions from Hobbyking you may pay a little more, but the quality should be reliable. You can get them with a power supply built in which will either have AC in the name, or be marked as AC/DC. If it doesn't say AC somewhere in the listing then you will need a power supply.

I have read good things about the ISDT chargers as well, and some of them are very reasonably priced.

I have a Hitec RDX1 charger, and a Turnigy 80w four button charger (B6 clone). Both have been reliable for years.

 

[Ketchup]

I also have a hitec charger (the RDX1 Pro) and it is a very good charger. It has been serving me well for around 4 years now and I haven’t had any issues so far. The only problem with it is that you can only charge one battery at a time. In the beginning it may not sound like a problem, but it can become limiting once you start having to charge more packs.
I haven’t owned a B6, but I have heard good things about them and you should be fine with one of them as long as you can find a good one

 

[jtrops]

I also have a hitec charger (the RDX1 Pro) and it is a very good charger. It has been serving me well for around 4 years now and I haven’t had any issues so far. The only problem with it is that you can only charge one battery at a time. In the beginning it may not sound like a problem, but it can become limiting once you start having to charge more packs.
I haven’t owned a B6, but I have heard good things about them and you should be fine with one of them as long as you can find a good one

I haven't tried parallel charging with the RDX1, but I use the Turnigy mostly for parallel charging. As long as your batteries are healthy and you get the c rate correct you should be able to parallel charge with the RDX1 Pro (it can output 100w).

 

[Superman11497]

Thanks guys I really appreciate your advice. Just ordered my new charger, and an excited to get back up in the air

 

[Merv]

....For whatever reason one of the cells in my battery pack is severely low. I think the issue lies with my charger.....

Depends on how low that one cell is. If it’s between 3.5 to 2.7, it could be the charger.
If it’s between 1.5 and 0, it’s the battery. It not uncommon for one cell of a pack to just go bad.