abufletcher

I've got a HiTec 4.8V / 600mAh 4-cell NiCd battery that when discharged on my Hanger9 Sure Cycle charger reads 478 and 5.8V. It was reading fewer mAh but after a few discharge/charge cycles it got up to 478. On my Hanger9 digital variable load voltmeter (set at 1A) it reads 5.55V and 4.82V under load (i.e. with the load button pushed).

What does that all mean? Is this battery good?

RCHubbub

It's a matter of opinion. I would not trust it as it appears that there is a weak or dying cell in the pack that could drop out unexpectantly to the point that you lose your receiver especially if there is a lot of servo action going on which only hastens the voltage drop. Not knowing the history of the battery or even if it's brand new, typically I stop trusting a battery when it won't hold 80% of its rated capacity, or if I have a voltage drop of more than 0.3vdc between no load and a reasonable load. Your battery fails both those parameters for me personally to think of using it.

abufletcher

That's just the answer I was needing. Thanks. I'll put it away to be used when "setting up servos" but not for flying.

So now I need to order another couple of Rx batteries. To tell the truth, I haven't had a lot of luck with batteries. All of the batteries that came with the various Airtronics flight packs are now dead. As are two I bought from SR Batteries (actually those packed up very quickly). I think this was the result of using (and maybe "overusing") those wall-charger units that come with the radio. Now that I have the Hanger9 charger, things seem to be going better.

Initially I always just pulled the Rx battery out of the model to charge it. This meant I could swap them around to different models. But on serious scale models, it's usually buried so I just charge it in the model through the extra wire on the switch. I haven't gotten into using charge jacks yet. On my most recent ARF (Black Horse Chipmonk) for balance the Rx battery needed to hidden underneath the cowl so no ready access. All this means that I'm ended up needing an Rx battery for just about every model I have.

If you haven't noticed by now: I HATE BATTERIES!

GarySS

My Feedback: (13)

I tend to agree with RCHubbub, but you might just put the battery on a slow walwart charge for a full 24 hours and then after a little rest (1 hour +/-) cycle it. Sometimes they wake up with use.

nine o nine

My Feedback: (1)

It seems that the mah capacity on that pack is down but I don't understand how you can be seeing 5.8 volts on it. Off a fresh charge a 4.8 pack might show 5 or 5.1 volts but not 5.8....did you make a typo??? Anyway, if a 600 mah pack will only give you 480 on a test after recycling a few times I'd only use it as a bench test pack as you've suggested.
Mitch

abufletcher

No typo. The Hanger9 charger almost always reads 5.8V for a full charge on the 4.8V rated batteries.

I'll give it one more shot with the 24-hour wall charge, plus wait, plus recycle as GarySS suggests. At any rate, I'll be buying a couple more new 800aHm batteries.

summerwind

hence the reason to use a redundancy system.............at least use a 5 cell pack as if one cell does go bad, you still have power.

2- 5 cell 600mah packs running through 2 standard switches to the Rx is a no brainer for anything you value in the air, not to mention the safety factor against using a single pack that if gone bad, you now have a deadly missle in the air right?

2 of these,
http://www3.towerhobbies.com/cgi-bin...?&I=LXH338&P=0

is only an ounce heavier than one single pack like you mention.
running 2 switches assures you that if one swtich goes bad, you still have control...............chances of 1 switch going bad and the remaining battery going bad are astronomical.

link to redundancy system,

http://www.hangtimes.com/id33.html

abufletcher

Again: I hate all things electric. Just reading that website on the technical aspects of batteries and their wiring makes my brain burn. [:@] So unless the recharging of a double battery setup is as brainless as charging a single battery, I don't think that's for me. Also, adding an additional battery represents a significant weight addition to a 1/6 scale model. True that it's better than adding lead, but also adds to the complication.

I still don't really understand the practical difference between a 600mAh pack and a higher capacity pack. I'm using a 1000mAh pack on my Puppeteer and that lets me fly for at least 1 hour (6 x 10 minute flights) without recharging.

abufletcher

I've always used the normal AA size battery packs in either the 4-cell or 5-cell flat configuration. Any reasons to change this?

TFF

With the perfect 600mah 4.8v battery, you should have 4.8v or better for 600mah meaning at a 600 miliamp load it will run for 1 hour. WE use batterys in sperts not in solid loads. A battery that will hold 75% of its rated capacity is considered ok. So 75% of 600 is 450; if your capacity is better than 450mah it is considered ok. When the voltage drops below the 4.8 there is no excess amps to draw from and the battery will crash and take your plane along with it.

abufletcher

And how would one know what load the battery is running at one any given model? All I know is that I HAVE flown for 1 hour on a 1000mAh battery. Now that i have the Hanger9 voltmeter, I can at least check the voltage after a few flights. But how would I know how much "gas" is left at that voltage?

Steve Percifield

My Feedback: (14)

Cycling. After one of your flying sessions, discharge the battery on your cycler, that will tell you the capacity left in the pack after a normal day of flying. Also, you should format a new pack or one that has slept over the winter. SLOW charge the battery for the first 3 or 4 cycles to bring it back to capacity. After that you can peak charge.

abufletcher

What's the difference between slow charge and peak charge?

summerwind

you find a redundancy system difficult?..........you really want to not try at this stuff eh?......adding a second battery like i explained adds 1 whole ounce. hardly a weight penalty.
since you don't understand batteries, the system in the article is very easy to do and is probably best for someone who doesn't have a clue about reading batteries....otherwise you wouldn't be asking right?
if you want to make it real easy and not have to ever worry, then get a drycell box, use Eneloops, and just plug the battery into the Rx when ready to fly..........change the batteries between each flight............LOL

abufletcher

Using the tips here, it looks like I was able to bring two battery packs back from the dead. One was a Sanwa 4.8V 700mAh (4-cell) pack that's now discharging 637mAh after an overnight wall charge and showing 5.52V on the voltmeter (5.0V under load). The other is the HiTec battery (600mAh) that's now reading in 550.

summerwind

you can use an Eagletree system for finding the load of your onboard system to check what your flight pack is pulling, but the easiest way is to fly a normal flight and then recharge to see what goes back into the pack. this is only a ballpark though as capacity drain will change as voltage goes down over normal use.

Tiff explained it quite well, but you just don't know what the drain time is until you know what your flight pack demands.

summerwind

when you say "brought back from the dead", what do you mean?
if your playing with old rundown batteries, then your playing with the life of your plane...............what is cheaper, new fresh packs, or the plane?

abufletcher

Well, I may be overstating things a bit. But my eyes do start to glaze over as soon as people start talking volts and amps. I don't think I could ever make the transition to electric. But I am learning (ever so slowly) how to keep my batteries charged. And the dual battery system actually looks doable and would probably be a good idea on a serious scale model. And I suppose adding batteries is better than adding lead.

summerwind

now you're getting it.
the size of the packs can be a full pack but split in 2 so as to save weight.
the ones i listed are about 3.3 ounces each, so they add up to just ove a standard pack.
my N28 will use 2 standard packs as i need the nose weight anyways.

i can understand your not fully understanding this stuff, but seriously, ever since being here and seeing your work, you're more than smart enough to pick it up, just need things explained thoroughly.......i know i did, but then it clicked and became super simple.

all in all though, it takes some reading.
you will also get a better understanding from posting in the batteries forum.

for me and all the years i've been into RC (since 1969) i have seen a few batteries puke for no reason.
buying a new battery pack and cycling it a few time to make sure it is reaching or exceeding it's rated capacity is all i need to make sure i'm not going to crash due to an old battery that may or may not puke on me. cheap insurance i say.

abufletcher

Maybe I'm just expecting too much from battery packs. How long is a pack supposed to last? Is it unreasonable to expect to use a pack for a year or more? Should I just buy them by the gross and chuck'em every couple of months? Seems like I'm always buying new batteries and then just a few months later having them losing capacity.

Seriously, the battery seems like the one GREAT UNKNOWN in my whole RC world. I always charge the night before, if I think I might fly the next day. I have the Hanger9 charger and I recycle the batteries once a month or so. At the field I'll fly for maybe 40 minutes then check the charge remaining on the Hanger9 voltmeter. If it looks ok, I might put on one or two more flights. Then I call it quits. I don't have the gear to charge at the field and honestly after an hour in the air, I'm usually beat for the day.

summerwind

Don,

i have to leave in a bit, but i would be more than happy to hook up my system i am using for 40 size flyer to show you how easy it is to hook things up.
i'll shoot a couple pics and post.....let me know.

also, when using 2 batteries, you actually double your capacity...........2x600 mah equal 1200mah.

summerwind

i know someone who has been using the same pack for over 10 years.
it's all about good vibration isolation and checking the capacity from time to time and keeping the cells properly charged.

i prefer to change out packs every couple years, but that's me.

abufletcher

I'm not quite sure what you count as a "standard pack" since my Sanwa 4.8V/700mAh/4-cell pack, which I think of as "standard" weighs just under 3oz (83g).

BTW, here's the "battery gear" I have at the moment. I bought the ParkFlyer Peak Charger before I got into RC proper and to be honest I've really never understood what to do with it (other that to plug and unplug batteries). For example, I don't know what I'd connect the alligator clips to. Is this usuable? Obviously, I'd need a different "pig tail" to charge normal connection battery packs, but I'm sure I could cut one off an old wall charge. And then I have a couple of the Airtronics wall charger units (probably at least three of them). More recently I got the Hanger9 Sure Cycle and the Hanger9 voltmeter.

Notice that, as I mentioned above the Sure Cycle ALWAYS displays 5.8 (or even 5.9) volts on a fully charged 4.8V pack. Why is this. Could this be the result of using this American charger on Japanese house current (110V, but I think it's 50hz (or something like that)?

abufletcher

I'll have to remember to do this. Thanks.

summerwind

Don,
i guess my thought of a standard pack is a 1000mah 5cell which is around 5.5 ounces.
your 600mah 4.8 packs are the lightest, but they can be split in 2 as well.

thing is, if you maintain your battery properly, you'll likely never experience an issue, but there is always that chance.
with todays radios the failure rate is next to nothing, but the switch and battery are still the culprit in a crash from time to time.
for anything of hard work and value, i prefer the dual switch/battery system as it removes a chance of failure and loss of control.

a current model i'm working on will travel at around 130mph in level flight.....i certainly wouldn't want to lose control of such a missle.

seriously, read all you can on battery info and you'll understand a lot more.
with new battery packs, cycle them a few times and note their discharge capacity after a full charge...............check them periodically and compare that to new.
when you lose 15% of the capacity of new and well maintained batteries, then watch them closely.