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Help! Helicopter help

#1
I have a slight problem with an rc helicopter. It is a JiaYuan 1698 and when i tried to use it didn't have enough power to lift it's self off the ground. It uses a battery made of 8 AAA batteries connected in parallel. I later discovered that it had a loose wire on the motherboard of the heli and i am not sure weather it is a connection issue or a power issue. Now the wire is completly disconected, I will solder it at some point, but the question still applies. Do i need a bigger battery or not? Please give me advice. Thank you in advance.

 

Mad_Mechanic

Well-known member
#2
I would attempt to fix the wire on the main board for sure. As for the battery, it sounds like it uses a pre-assembled rechargeable pack. Make sure the pack is fully charged.

Did you buy this heli new? If you bought it second hand, the pack might be beyond it's useful life.
 
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PsyBorg

Wake up! Time to fly!
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#3
You sure about the batteries mate? The triple a batteries are probably for the radio and the helicopter is powered by a lipo as normal batteries are wayyyy to heavy for that tiny heli let alone not dense enough power storage.
 

Mad_Mechanic

Well-known member
#4
That's a good point. Looking a bit more closely at the picture on the box, I highly doubt it has a proper place to mount a pack the size of 8x AAA. It probably uses a 1s lipo, maybe a 2s like my old blade cx2 did.
 
#5
I would attempt to fix the wire on the main board for sure. As for the battery, it sounds like it uses a pre assembled rechargable pack. Make sure the pack is fully charged.

Did you buy this hello new? If you bought it second hand, the pack might be beyond it's useful life.
The helo is not second hand but its pretty old. I had it tucked away and desided to try and fix it. Also it has its battery replased once already but since that is old by its self i will buy a new one
 
#6
You sure about the batteries mate? The triple a batteries are probably for the radio and the helicopter is powered by a lipo as normal batteries are wayyyy to heavy for that tiny heli let alone not dense enough power storage.
No i am shure. The helo is prety old and came with a battery made like this with a heatshrink cover on tge outside. I replaced the battery with one that my uncle made but was a bit heavier. I am planing on buying an all new battery for it so that problem is gonna be sorted out.
 

Mad_Mechanic

Well-known member
#7
I wonder if the original pack was actually made from lithium-ion cells that were close in size to AAA. While not impossible, it seems unlikely that standard rechargeable AAA cells would have energy energy density (power for weight).
 
#8
That's a good point. Looking a bit more closely at the picture on the box, I highly doubt it has a proper place to mount a pack the size of 8x AAA. It probably uses a 1s lipo, maybe a 2s like my old blade cx2 did.
If you take the canopy of, whitch is the proper way to get to the electronics an d the battery you will see that most of the space is occupied by the battery its self
 
#9
I wonder if the original pack was actually made from lithium-ion cells that were close in size to AAA. While not impossible, it seems unlikely that standard rechargeable AAA cells would have energy energy density (power for weight).
When i replased the original battery i took it apart. It was liderally made of 8 AAA batteries connected in parallel. But curiously they were lighter then convensional ones.
 

PsyBorg

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#13
To be honest if you really want to put this in the air. It would probably do good to make the swap over to lipos as they are much lighter with higher power density and will give better performance and flight time.

Figure out what the fully charged voltage of that 8 cell is and we could figure from there a proper lipo for it.

If you gotta replace things mays well upgrade.
 
#14
To be honest if you really want to put this in the air. It would probably do good to make the swap over to lipos as they are much lighter with higher power density and will give better performance and flight time.

Figure out what the fully charged voltage of that 8 cell is and we could figure from there a proper lipo for it.

If you gotta replace things mays well upgrade.
The existing battery uses an sm2.54-2p connector but all the lipos that i have seen use an st60. Is the sm2.54-2p gonna be enough? I guess it depends from the voltage right?
 

PsyBorg

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#15
Changing the heli connector to an xt30 and sourcing lipos with xt30s is a minor change.

My gremlin uses a 3s 450 mah battery to run 4 motors for 6 to 8 minutes depending how many crashes I have to walk to hehe.

Main factor for your change over is matching voltages and then buying batteries as close to the weight of the current battery configuration to keep cg.
 
#16
Changing the heli connector to an xt30 and sourcing lipos with xt30s is a minor change.

My gremlin uses a 3s 450 mah battery to run 4 motors for 6 to 8 minutes depending how many crashes I have to walk to hehe.

Main factor for your change over is matching voltages and then buying batteries as close to the weight of the current battery configuration to keep cg.
I guess you are right since a bigger cable wouldn't have problems with lower rated voltages but a thinner one would. The manual says that with the stock battery you need 2 hours of charge so i guess that just adding the volts of 8 AAA batteries would give me the required amount am I right? (P.S. Love the profile picture ;-) )
 

PsyBorg

Wake up! Time to fly!
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#17
Its best to put a meter on the fully charged pack. That way you dont miss out hidden connections in that battery holder and get a series parallel configuration confused with a straight up series. That would cause much drama when you plug in a pack to large for the electronics.
 
#18
Its best to put a meter on the fully charged pack. That way you dont miss out hidden connections in that battery holder and get a series parallel configuration confused with a straight up series. That would cause much drama when you plug in a pack to large for the electronics.
I should probably say that i have replaced the battery once and it currently has one that i made. Here are some pictures.
They are taken 180 degrees rotated from each other. They are all connected in series with no extra cables or capacitors.
231370_58ed17f54dd09cb543e3d45eafebde3b.jpg 231372_bb9ab4a3408eabc7d3599b04f309d1af.jpg
 

PsyBorg

Wake up! Time to fly!
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#19
Ahhh bummer. Was hoping for a series parallel config. 9.6v is smack in between 2s and 3s lipo.

Probably better going with 9.6v nicad packs and get the mini tamaya connectors or xt30 if you dont mind living outside industry standards.
 
#20
Ahhh bummer. Was hoping for a series parallel config. 9.6v is smack in between 2s and 3s lipo.

Probably better going with 9.6v nicad packs and get the mini tamaya connectors or xt30 if you dont mind living outside industry standards.
Well the motherboard of the heli doesnt look like it has any tolerances so i guess you are right. Thenks for helping. I dont think i could have done anything without the advice from all of you guys :)