chevypower1930

Hey everyone, I've been worrying about my big .60 size P-51 Miss America.... My question is how could I check the receiver battery after the winter for the spring flying season.... and do yall think this battery could go bad, its a hydrimax 3600 nimh pack, I've actually flown the P-51 a few times throughout the winter, and it doesn't get TOO cold down here in Raleigh, NC... doesn't get below freezing too much, I've stored it in the garage with the door shut and sometimes inside, I charged the battery for the past 2 days and nights and today just switched it on, turned on my TX and everything is operating great, retracts working great, all servos reacting quickly... Do you think there's anything to worry about before I fly this weekend?
Thanks! here's a video of the plane by the way! JUST got my retracts working correctly last night, so the retracts were down in this video.....
http://www.youtube.com/watch?v=0HRzw8Jm7aQ

jay2000dakota

Does Your charger have a cycle option? if so set cycle for maxium draw and wait. Cycling will tell you how long the battery will last under full load. For example my 1600mh nicads last 88 mins under 500 miliamp constant load.

chevypower1930

hey jaydakota no the chargers just one of the chargers that has a TX charge lead and an RX charge lead.... I don't think I have much to worry about... the battery was just bought about a month before winter hit.... so I think I'll be alright... I just want to be COMPLETELY sure.

Ram Jet

You ought to be talking to "sticktickler", member here. He know a load about batteries. Hey stick, ya listin'? Help us all out please.

Bill

Ram Jet

I'm no expert but I think you should cycle your battery once per month. Full charge then nearly full discharge and then full charge. Somebody here who knows what they are talking about will give you the skinny.

Bill

jaka

Hi!
You don't have a "volt watch ???
No cycling of NiMH batteries are needed!!
http://graphics.hobbypeople.net/gallery/701699.jpg

David Bathe

Jez, thats certainly one Big Block battery C' power.
Why so big?
Anyway, why not just buy a new, normal sized one if you're unsure?

p39

My Feedback: (5)

Hey Chevy... if you're using a 3600mah pack and charging it withe the "wall charger" that came with teh raio, make sure you're getting enough charge on the receiver pack. 16 hours is not enough......

OldScaleGuy

My Feedback: (2)

Your battery pack is still basically new, you should be fine, save your money. Charge it just prior to going flying, check to confirm the voltage is correct, give it a good range check before putting it in the air, make your first flights relatively short and check the voltage between flights. Enjoy!

Mode One

Cycling batteries is the only way to know if everything is O.K. If your going to be in this hobby a while, why wouldn't a person buy and use a cycler? They are the best/cheapest insurance policy there is for not having your batteries crap out on you. NiMH batteries can be damaged by overcharging!

chevypower1930

Hey ya I keep the battery in that charger for A WHILE, and modeone I've NEVER heard of NIMH batteries getting damaged from over charging? especially on a small wall outlet charger... guys keep there batteries on the chargers for weeks at a time..

chevypower1930

hey david.. well the Hangar 9 P51 uses 6 servos, so just wanted to be on the safe side...

jet60

NiMH BATTERIES CAN BE DAMAGED BY OVERCHARGING?? where did you come up with that?
actually, any battery can be damaged by overcharging.
about the only thing you said that makes any sense is that cycling is a good idea.
you must be one of them old timey guys

WCB

quote:

Mode One's post made sense to me. Maybe I'm an "old timey guy" too.

Steve Collins

My Feedback: (8)

Do yourself a favor and get a decent charger that also cycles batteries. Here is one I highly recommend:

http://www3.towerhobbies.com/cgi-bin...&I=LXKSY1&P=SM

Don't be fooled into thinking that your wall charger is fully charging that battery pack. It is highly unlikely that it is. That wall charger was designed to charge the size battery pack that came with the radio. IMO, a much better charger is a wise investment. Saving bucks has cost many of us the loss of planes before.

Rodney

Yes, NiMh batteries are very easily damaged by overcharge, much more so than NiCad but both will suffer from excessive overcharge. Fortunately, NiCad will sustain little damage from overcharges at less than 0.1C but NiMh will be easily damaged from such practice. Actually, the only reason for cycling a battery is to check for capacity and should only be done occasionally, once or twice a year if they are being used weekly and also after any prolonged storage period. If you want some good info on batteries, check out the following sites:
http://www.rcbatteryclinic.com
http://www.whenshtf.com/showthread.php?t=2153
http://www.srbatteries.com/nimh.htm
http://dansdata.com/gz011.htm

jet60

well he's wrong about the NiMH specs.
but mostly i see him insulting others all over this site and i guess that's the sign of old age and arrogance. being nice to people is not Mode Ones fortee[]

Mode One

The following is quoted from Red Scholefield at the R/C Battery Clinic on the topic of NiMH cells. This, along with my own experiences, is what my opinions are based:

Nickle Metal Hydride - the picture today.

The Ni-MH that are available to us today from Sanyo/Panasonic may be treated essentially the same as Ni-Cds –EXCEPT FOR PEAK CHARGING. You have to be careful here. Some chargers will accommodate them, others won’t - and end up severely overcharging them to the point of destruction.

In a given cell size Ni-MH has on the order of 20 to 30% more capacity than Ni-Cds. They have slightly higher internal resistance, but not enough to concern us in most R/C control applications. This higher internal resistance can be of concern in electric flight operations where it is common practice to add an additional cell to compensate. They have a shorter cycle life in general, but again not enough to be of real concern. Most people run out of calendar life before cycle life in flying R/C. Meaning that the separator system in the battery (same for both types) fails (shorts) before the cells fade away in capacity delivery ability. Ni-MH are less tolerant to abuse (excessive high rate discharge, excessive overcharge, vibration, cell reversal) than Ni-Cd – but again, it seldom becomes an issue if reasonable care is given in the installation and maintenance of the packs. Ni-MH capacity falls off with cycling whereas Ni-Cd stays pretty constant, seldom going below 80% before shorts develop. Ni-MH has a higher self-discharge rate (3-4%/day) than Ni-Cd (1%/day). Ni-MH cost a bit more per Ah of capacity.


Red S.
Red’s R/C Battery Clinic
http://www.rcbatteryclinic.com

Updated 2/04

I am using NiMH cells as well as NiCADS. I feel NiCADS are a better cell for my use as they are tougher and better suited for how I use rechargible batteries!

Ram Jet

Great info. I thought the sun rose and set on NiMH batteries. I'll adjust my expectaion levels.

Thanks,
Bill

Jester241

You batteries should be fine. The only thing that concerns me is if (not sure what you meant) you let them on the charger for 2 or 3 days straight. I still doubt that would hurt them,but I wouldnt recommend it. Many guys charge them like 4 hours a day everyday and it dont hurt them though. I keep my batteries in my garage where it gets well below freezing everyday in the winter and they still work,lol. And I've never cycled anything(although I should).

chevypower1930

Hey Jester, ya I hear ya that's what I was thinking cause I've been flying glow planes for 4 years now.. I'm only 19 haha and I've never had a reciever battery problem.. with the way I charge... the most I keep the batteries charged is maybe overnight to 2 nights rarely.... so i don't think it'll be a problem

Mode One

Chevypower1930, you asked for guidance on the care and feeding of your airborne batteries. You have recieved some really good information and suggestions on how to go about doing this from knowledgable people with longevity in this hobby. Now, what you do with this information, is totally up to you!

chevypower1930

Hey Mode One.. yah I know I'm deffianatly going to grab a battery charger with a cycling feature.. I'm gonna grab a volt watch too.. tryin to keep my planes airborne! haha Thanks

poison

ya get a voltage meter for sure and check after ever flight, thats how I do, and 2 night charge sounds a bit much.