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Apr 11, 2018, 12:42 PM
no way
Hi
what are the end of charging normal voltages on small lipos for you guys? I get 4.17 volts per cell on new batteries , is it problem with my charger or what, when i charge rest of my bigger lipos i normally get 4.20 per cell on full charge, also IR is quite high (above 100 miliohms) on these small lipos.
Do you have same issue??

regards
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Apr 11, 2018, 01:27 PM
Registered User
Blaze0021's Avatar
Quote:
Originally Posted by romano_st
Hi
what are the end of charging normal voltages on small lipos for you guys? I get 4.17 volts per cell on new batteries , is it problem with my charger or what, when i charge rest of my bigger lipos i normally get 4.20 per cell on full charge, also IR is quite high (above 100 miliohms) on these small lipos.
Do you have same issue??

regards
Its fairly common (from my experience anyways) for lipos to drop a hundredths of a volt after a few minutes after a charge. Most of my batts come down to 4.17-4.18 volts after its sat for 10-15 mins waiting for the next flight. Unsure about the IR rating inquiry however.. Other pilots could probably chime in here.
Apr 11, 2018, 02:01 PM
Registered User
Woody_99's Avatar
Quote:
Originally Posted by romano_st
Hi
what are the end of charging normal voltages on small lipos for you guys? I get 4.17 volts per cell on new batteries , is it problem with my charger or what, when i charge rest of my bigger lipos i normally get 4.20 per cell on full charge, also IR is quite high (above 100 miliohms) on these small lipos.
Do you have same issue??

regards
Yeah, these little batteries have really high IR, and I think that might be why the full charge voltage drops off so quick. It's probably 4.20 to the charger, but as soon as the charge current is removed, the voltage drops a bit.

I've found that sometimes if I lower the charge current, they end up closer to 4.20 off the charger, but in actual use that .03v isn't too significant.
Apr 11, 2018, 02:08 PM
Registered User
mdmyers's Avatar
Quote:
Originally Posted by Woody_99
I used the adjustment loops to get all the control surfaces neutral. (they were all off some) Tail wheel's not lined up, and I'm hesitant to put too much twist on it. Probably going to take the gear off after maiden anyway.

Any more I should do to it?
Don't recall for sure but I believe if you open up the fuselage you'll find an adjustment loop for the tail wheel?
Apr 11, 2018, 02:09 PM
Registered User
Blaze0021's Avatar
Quote:
Originally Posted by Woody_99
Yeah, these little batteries have really high IR, and I think that might be why the full charge voltage drops off so quick. It's probably 4.20 to the charger, but as soon as the charge current is removed, the voltage drops a bit.

I've found that sometimes if I lower the charge current, they end up closer to 4.20 off the charger, but in actual use that .03v isn't too significant.
Yes thats very true. I've found that if I charge at a higher C rating (2C for example), the finishing charge is not nearly as close to 4.20 a cell. But if I charge at the normal 1C or even 1.5C, (which is what I normally charge at), I can get much better accuracy to 4.20 a cell. I even use the Common Sense Parallel Boards and will charge them all at 1.5C rating and will get very close to 4.20 a cell.
Apr 11, 2018, 02:14 PM
Registered User
Blaze0021's Avatar
For anyone else in here that keeps some of their planes in the garage, has anyone ever used a dehumidifying unit where they keep their models? And if so, whats been the experience? While the planes in my second bedroom are very protected from the elements, I am a bit concerned with the ones I keep in my detached garage. Its fairly insulated, but on the days that it rains or snows and my car gets stored in there with a some snow or moisture on the car.. well you get the idea.

Just being a bit overprotective with my little toy investments considering that I have a lot of them....
Apr 11, 2018, 02:25 PM
no way
Thanks guys for help!.. so its normal for small batteries to have high IR... so i ordered 10 more nanotech 300 mAh for nothing
normally on my 6s packs i measure IR below 10 miliOhms, on some better packs it goes under 5 miliOhms

regards
Apr 11, 2018, 02:30 PM
no way
Quote:
Originally Posted by Blaze0021
For anyone else in here that keeps some of their planes in the garage, has anyone ever used a dehumidifying unit where they keep their models? And if so, whats been the experience? While the planes in my second bedroom are very protected from the elements, I am a bit concerned with the ones I keep in my detached garage. Its fairly insulated, but on the days that it rains or snows and my car gets stored in there with a some snow or moisture on the car.. well you get the idea.

Just being a bit overprotective with my little toy investments considering that I have a lot of them....
I always use silica gel packs when i store electronics for longer time and i never had any oxidation , regarding models, especially balsa planes i thin its even good to have little bit moisture in air to keep wood from becoming too dry.

regards
Apr 11, 2018, 02:37 PM
Registered User
Blaze0021's Avatar
Quote:
Originally Posted by romano_st
I always use silica gel packs when i store electronics for longer time and i never had any oxidation , regarding models, especially balsa planes i thin its even good to have little bit moisture in air to keep wood from becoming too dry.

regards
I think you're right.. one of my buddies also said the same thing about having a little moisture. He said about 30-35% humidity is fine. I just wasn't sure of the effects of long term garage storage on RC aircraft when it comes to their internals (RX / ESC / motor, etc). I have a temp / humidity gauge in the garage, so I'll keep an eye on that.

Probably just me being overly protective. I'm that RC guy that when I bring a model to the field that has been in production or out of production for some time, someone on the field has to come up and ask if I just bought the plane or if I even fly it at all because they all look so new and unused.
Apr 11, 2018, 02:48 PM
aka ShadowVFX
Suko's Avatar
I have dozens of planes that've been stored in my garage without any issue. I live near Seattle, so we get plenty of rain too. Unless it is an open air garage, I wouldn't worry about it as long as the planes aren't getting directly hit with water.
Apr 11, 2018, 02:54 PM
Does it have invasion stripes?
SanDiegoUteFan's Avatar
Quote:
Originally Posted by Blaze0021
I think you're right.. one of my buddies also said the same thing about having a little moisture. He said about 30-35% humidity is fine. I just wasn't sure of the effects of long term garage storage on RC aircraft when it comes to their internals (RX / ESC / motor, etc). I have a temp / humidity gauge in the garage, so I'll keep an eye on that.

Probably just me being overly protective. I'm that RC guy that when I bring a model to the field that has been in production or out of production for some time, someone on the field has to come up and ask if I just bought the plane or if I even fly it at all because they all look so new and unused.
That's funny. A club member walked up to me the other day and said, "How do your planes always look like they're brand new?"

The guy next to him said, "He doesn't crash 'em!"
Apr 11, 2018, 03:12 PM
Registered User
Blaze0021's Avatar
Quote:
Originally Posted by SanDiegoUteFan
That's funny. A club member walked up to me the other day and said, "How do your planes always look like they're brand new?"

The guy next to him said, "He doesn't crash 'em!"
Hahaha, its a good problem to have. My only problem now is that I'm out of room.
Apr 11, 2018, 06:18 PM
Curse you, Red Baron!
Crash Override's Avatar
Quote:
Originally Posted by romano_st
Hi
what are the end of charging normal voltages on small lipos for you guys? I get 4.17 volts per cell on new batteries , is it problem with my charger or what, when i charge rest of my bigger lipos i normally get 4.20 per cell on full charge, also IR is quite high (above 100 miliohms) on these small lipos.
Do you have same issue??

regards
Quote:
Originally Posted by Blaze0021
Its fairly common (from my experience anyways) for lipos to drop a hundredths of a volt after a few minutes after a charge. Most of my batts come down to 4.17-4.18 volts after its sat for 10-15 mins waiting for the next flight. Unsure about the IR rating inquiry however.. Other pilots could probably chime in here.
Quote:
Originally Posted by Woody_99
Yeah, these little batteries have really high IR, and I think that might be why the full charge voltage drops off so quick. It's probably 4.20 to the charger, but as soon as the charge current is removed, the voltage drops a bit.

I've found that sometimes if I lower the charge current, they end up closer to 4.20 off the charger, but in actual use that .03v isn't too significant.
Quote:
Originally Posted by Blaze0021
Yes thats very true. I've found that if I charge at a higher C rating (2C for example), the finishing charge is not nearly as close to 4.20 a cell. But if I charge at the normal 1C or even 1.5C, (which is what I normally charge at), I can get much better accuracy to 4.20 a cell. I even use the Common Sense Parallel Boards and will charge them all at 1.5C rating and will get very close to 4.20 a cell.
Everything you never wanted to know about batteries:

http://batteryuniversity.com/
Apr 12, 2018, 06:07 AM
no way
Have anyone made simple battery door "mod", i am looking in posts but cannot find??

regards
Apr 12, 2018, 08:35 AM
Registered User
Blaze0021's Avatar
Quote:
Originally Posted by romano_st
Have anyone made simple battery door "mod", i am looking in posts but cannot find??

regards
I did the battery door mod with my (3S) UMX P-47: https://www.rcgroups.com/forums/show...-%28Part-II%29

See photos in the link I posted above. Very simple to do. I cut the top nose part of the fuse right on the panel line with an X-Acto knife, and made a hatch that hinges with a small strip of gloss tape on one side and micro magnets on the other side. Very clean. You can most likely do the same with the UMX P-51.


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