Upgrading to LiPo's and getting mixed information.

skivit48
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Posts: 192

Upgrading to LiPo's and getting mixed information. Mar 20, 2010 20:05:18 GMT 1

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Post by skivit48 on Mar 20, 2010 20:05:18 GMT 1

I am in the process of upgrading my original (red) Super Cub to LiPo batteries since my NiMh batteries are no longer any good.

I went to the LHS today and in my conversation with the tech guy he said that the receiver for the original super cub would fry no matter what I did. (changing connectors, LVC jumper and prop). He also said that Hobbyzone increased the amps that the ESC/Receiver could handle.

This seems to be contradictory to the research I have done for the last month. (on this site and others) I have already purchased batteries and a charger and have changed my connectors to EC3, except for on the receiver. I haven't modded the battery box yet but that is coming soon. Wondering if I now need to buy a replacement receiver that is for the LP. I am a noob and all but I am just trying to make sure I am on the right track.

I am still doing research and trying to learn as much as I can. I've said it once and I'll say it again this place has been an amazing resource. As well as a good laugh every once in a while. Thanks to everyone for their help, guidance and patience. Also Flydiver has posted several good links on other threads for learning about batteries and their care among other things. Thanks for that and your other help too Fly.

Skivit

ginginho
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Upgrading to LiPo's and getting mixed information. Mar 20, 2010 21:01:58 GMT 1

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Post by ginginho on Mar 20, 2010 21:01:58 GMT 1

The original red SC electrics work fine with a 3S lipo, so the guy in the shop is talking b0ll0x, probably just trying to sell you stuff. You need to remove the LVC jumper and prop down a bit, but that's all. It sounds like you've already researched this well so you should be good to go. The motor probably won't last as long as it should do, but they are cheap as chips, so it's no biggie.

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skivit48 Squadron leader Posts: 192	Upgrading to LiPo's and getting mixed information. Mar 20, 2010 21:11:35 GMT 1 Quote Select Post Deselect Post Link to Post Member Give Gift Back to Top Post by skivit48 on Mar 20, 2010 21:11:35 GMT 1 I kept telling my wife that while we were there. I have been reading for a month and that I was pretty sure I was on the right track. Thanks Ging.

belem Squadron leader Posts: 210	Upgrading to LiPo's and getting mixed information. Mar 20, 2010 23:41:01 GMT 1 Quote Select Post Deselect Post Link to Post Member Give Gift Back to Top Post by belem on Mar 20, 2010 23:41:01 GMT 1 Yep, flew mine for quite a while with the original esc and lipos. Just make sure you pull the jumper.

killioughtta
Group captain

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Upgrading to LiPo's and getting mixed information. Mar 21, 2010 1:44:00 GMT 1

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Post by killioughtta on Mar 21, 2010 1:44:00 GMT 1

The guy at the LHS here told me the same spit. I told him tons of SC owners have done that and he was like "no way, man." and I said "ok, I'll go ahead and do it and take a nice long video of it for you and then you'll be able to help other people who come in here wanting to do the same as me" and I showed him video of the SC with a LiPo running for a few minutes and I brought in my SC to the store and showed him and he was like "I don't know how that could be, I thought it would fry it" and I said "Just make sure you let others know that's a nice upgrade." It works like a charm.

Last Edit: Mar 21, 2010 1:45:06 GMT 1 by killioughtta

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Dillzio
Air chief marshall

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Upgrading to LiPo's and getting mixed information. Mar 21, 2010 9:50:35 GMT 1

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Post by Dillzio on Mar 21, 2010 9:50:35 GMT 1

Yeah, the guy from your LHS is full of $hit. When I got my supercub LP the part number on it was HBZ7153 (the original receiver number), not HBZ7353 (the LP receiver number). The only difference is that the one from the LP has an EC3 connector.

supercubnz
Flying officer

Posts: 26

Upgrading to LiPo's and getting mixed information. Apr 4, 2010 0:12:47 GMT 1

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Post by supercubnz on Apr 4, 2010 0:12:47 GMT 1

I did not know about having to remove the LVC jumper but has used a 7.4v 800 mAh Lipo several times. I did not notice anything unsual. The motor cuts off when there is not enought battery power. Is it essential that I remove the LVC? If not what effect would it have? Can someone, please advise. Thanks.

flydiver
Air chief marshall

Posts: 3,293

Upgrading to LiPo's and getting mixed information. Apr 4, 2010 1:27:17 GMT 1

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Post by flydiver on Apr 4, 2010 1:27:17 GMT 1

LVC is when the ESC thinks it needs to cut power to the motor to still have control.
From the PZ manual-different plane, same ESC:
[When the jumper is present the auto-cut is set at about 5.7 volts, which works with 6- to 9-cell Ni-MH battery packs. When the jumper is absent, the auto cut is set at about 8.8 volts, which will function correctly with a 3S Li-Po Battery.]

This is fine for NiMh. It is hard on 2S lipo -it is disastrous to 3S lipo.
Lipos should not go below 3v/cell. So 2S should no go below 6v under power, 9v for 3S. So, if you fly to LVC that way you are shortening your lipo's effective life. Lipos do not like being excessive discharged.

PULLING THE JUMPER WILL NOT WORK FOR 2S for THIS ESC. In fact, it'll barely run since it will cut out at 8.8v.
Is that clear?
FOR THE HZ ESC PULLING THE JUMPER IS ONLY EFFECTIVE FOR 3S.
You need a more advanced ESC to differentiate between 2S and 3S. The HZ ESC is NOT it. (Unfortunately a bunch of ESC are not so hot). And, to get a 'better one' you have to upgrade everything.

If you want to maximize your lipo life you should fly by time and bring the plane down while it still had some power. You would like to see ~ 3.7v/cell resting after the flight.

OTOH a 2S 800mA is cheap so do what you will.
Interestingly 5 years ago that same lipo might have set you back $80.

Last Edit: Apr 4, 2010 4:29:47 GMT 1 by flydiver

Upgrading to LiPo's and getting mixed information.

Post by skivit48 on Mar 20, 2010 20:05:18 GMT 1

Post by ginginho on Mar 20, 2010 21:01:58 GMT 1

Post by skivit48 on Mar 20, 2010 21:11:35 GMT 1

Post by belem on Mar 20, 2010 23:41:01 GMT 1

Post by killioughtta on Mar 21, 2010 1:44:00 GMT 1

Post by Dillzio on Mar 21, 2010 9:50:35 GMT 1

Post by supercubnz on Apr 4, 2010 0:12:47 GMT 1

Post by flydiver on Apr 4, 2010 1:27:17 GMT 1