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NiMH Battery for RX, the achilles heel of your model

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Old 06-10-2014, 02:36 PM
  #51
Corsair2013
 
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I took your advise a while back Radfordc and now have dual Life in my large planes. NO issues and don't have to worry about one failure. It two fail then it was time to crash anyway.............


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Originally Posted by radfordc View Post
That's the beauty of a dual battery system. A battery can fail and you still have the other one to get you through the flight. Check both batteries before each flight by switching them on one at a time.
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Old 06-10-2014, 03:24 PM
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Uncas
 
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I now use 2 redundant batteries on planes that are important to me. I lost control of my Pattern plane last year and it crashed hard, not really sure it was the battery, but now I want the extra insurance. I buy my NiMHs from Cheapbatterypacks.com and usually get Elite or KAN batteries. For large planes I use 5 cell, for small planes I use 4 cell. They have been very reliable and super easy to charge. You need to periodically cycle them.

They do not last forever. To me four years is a very old battery.
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Old 06-10-2014, 11:10 PM
  #53
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I keep seeing people saying "ditch the 4.8 volt packs" and my question is WHY?????????????? I used the Futaba NR4J 600MAh 4.8 volt flat pack in my Kadet, still use them in my boats and have never had a battery related problem. This includes using receivers on the 72, 75 and 2.4 bands as well as digital, analog and brushless servos. When I bought a new Futaba 4PLS Telemetry system a few months ago, I installed a LiFe Source 1900MAh 3C pack in the transmitter. I haven't used it enough to know how long it will go without recharging, will be interesting to find out

Last edited by Hydro Junkie; 06-10-2014 at 11:25 PM.
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Old 06-11-2014, 04:15 AM
  #54
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Most the people saying it have had brown out problems when they went to 2.4 and found 6 volt to be the cure. With a plane like a Kadet with standard servos and not many of them a 4.8 pack is just fine and the new 2.4 systems aren't as sensitive to brown out. 6 volt gives full strength and speed to the servos and is a safe guard to the brown out problem. I run two 6 volt packs in all my bigger planes with a lot of digital servos and single 6 volt packs in my smaller planes. 4.8 is still fine for some planes. I went to eneloops, they are nimh but they don't self discharge, that's the only difference, charge today and fly next year if you like.
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Old 06-11-2014, 06:34 AM
  #55
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I fly giant war birds. Just switched back to nicads after watching friends giant Spitfire catch fire in the air using Lipos. Have used NIMHs since they came out with good luck but have never really been happy with their current draw capacity. I have some nicad packs that are still going strong after 10 years use so I have decided to switch back to nicads for my flight packs Weight is not a problem so using a lighter battery not really needed. Other than weight and potential memory problems nicads offer some good advantages. Long charged life, reliability, can discharge and charge at a high rate (I used to charge them at 5C all the time), don't need voltage regulators, don't need special chargers, don't blow up! OK, they aren't sexy, they aren't the latest and greatest, they just work! I pulled some nicad button cells I've had from the late 60's, never used or charged. (they used to be used for flight packs but were not reliable because they were hard to solder into a pack and vibration was a problem then) Put one on the charger just for grins, charged right up and held it's charge just like it was made today. Lets see you do that with any of the current batterys. As they say "There's more than one way to skin a cat"
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Old 06-11-2014, 06:51 AM
  #56
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Just asking, but I understand that nicads are no longer made because of the environmental impact of cadmium? Is that correct, or did I hear it wrong?
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Old 06-11-2014, 07:03 AM
  #57
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Just got some yesterday, so I think they are still available. I know for sure that Tower still lists Sanyo nicads. Like a lot of things the environmental impact is over hyped. Just look at the safety
rules printed on compact florescent bulbs. I had a friend who worked for a large steel mill in town who had to call a hazmat team in to clean up the mess when a thermometer fell and broke, because of OSHA rules! It's a bad joke anymore, everything is hazardous!
Larry

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Old 06-11-2014, 08:18 AM
  #58
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Quote:
Originally Posted by TomCrump View Post
Unfortunately, I've had the opposite luck with Hydrimax packs. They went bad in a hurry.

I'm in the process of moving over to eneloop packs. http://www.electrodynam.com/store/eneloop.html
I had 3 Hydramax NiMH packs go bad that were less than a year old. Switched everything over to LiPo and voltage regulators
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Old 06-11-2014, 10:27 AM
  #59
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Quote:
Originally Posted by TomCrump View Post
Can you elaborate on why you are switching from the eneloop packs ?

I have two packs, now, which I haven't yet used, but I am getting ready to purchase more.

What do you think of them for use in a TX ?

I am using a Lipo in my TX. It is great so far. This is my first season with the A123's. Honestly, I just do not have to charge them as much. I have a 2300mah pack in my .60 sized Sun FLi 5. I flew it 5 times the other day. Long flights, like 15 min. I only had to put 300mah back in. Not only that, they do not lose charge laying around. Never had trouble with the eneloops, it was just time to get away from NiMh. I wanted to be able to charge them faster. Which may have been the problem with some of my NiMh, I did not treat them properly.
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Old 06-11-2014, 12:12 PM
  #60
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Quote:
Originally Posted by d_bodary View Post
That would have been a shame forgot all about the ketchup until you mentioned the Venus. Glad it is still flying good for you. Only thing about a LiFe is make sure you can get to the balance leads for charging. my Pattern Plane is real easy to remove the battery, my sport plane it is buried in the plane and cannot remove it for charging.
You can get an extension to access the balance lead. It is said that it is important to keep the A123 batts balanced.
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Old 06-16-2014, 12:57 AM
  #61
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Quote:
Originally Posted by vertical grimmace View Post
I am using a Lipo in my TX. It is great so far. This is my first season with the A123's. Honestly, I just do not have to charge them as much. I have a 2300mah pack in my .60 sized Sun FLi 5. I flew it 5 times the other day. Long flights, like 15 min. I only had to put 300mah back in. Not only that, they do not lose charge laying around. Never had trouble with the eneloops, it was just time to get away from NiMh. I wanted to be able to charge them faster. Which may have been the problem with some of my NiMh, I did not treat them properly.
Thanks.

I'm giving eneloops a try. I'll have 5 packs for this season, and see how it goes.

I'm more involved in the building side of the hobby, and the new battery technologies are hard for me to keep up with. The eneloops are a more familiar technology, and easier for this old man to grasp.

I bought my first lipo pack last week, so the learning curve is still steep with that technology.
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Old 06-21-2014, 10:48 PM
  #62
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I've been using the VENOM 6v 1200 mA NiMH batteries now for the last 5 years, and haven't had any battery issues once I learned that a new battery pack needs to be cycled 3-4 times on a slow trickle charge prior to first use. Since this time, my packs have seen a lot of time sitting in planes waiting to fly and then just a quick charge before flight is all that's needed. I've flown with these packs quite a bit and have moved packs between planes as needed, and have not had a problem with these packs before or during my flights. During the winter months when I'm not flying, I do store the batteries with a full charge, and then do a 3-4 cycle charge at least once during the winter months and then another cycle charge just before the first flight of the new season. Overall, I've been very pleased with these particular NiMH packs, and am looking forward to buying another 3-4 more packs later this month for some new projects I have coming up.

I have heard some of the stories about NiMH not being a good pack, but my experience with these packs has been very positive and would recommend them as a good and reliable battery pack for my planes. I don't have any planes larger than a 60 size Dirty Birdy, and if I do decide to go larger, then I will consider going to LIFE's for these bigger planes. But until then, my vote is for these VENOM NiMH after they have been initally cycled 3-4 times before the first flight.

Just my $0.02 worth.......

Last edited by dakoris73; 06-21-2014 at 10:52 PM.
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