mCX Battery Life

[Jack Schmidling]

In about 3 weeks, I have gone though 4 batteries that no longer take
or hold a charge. I followed all the rules and suggestions.

I just returned from the local hobby shop with two new ones, put them
on the charger till it stopped blinking which was only a few minutes.

I am now using a timer set at 5 minutes and stopped flying the first
one when the timer went off.

I did the same with the second new one but after less than two
minutes, the led on board started flashing and the heli came down.

These are all batteries with the Eflite sticker on them but no clue of
the brand.

So, am I the only one with this sort of experience?

All all batteries equal?

Are there better batteries out their?

Thanks,

Jack

[Kevin]

Jack Schmidling wrote:
> In about 3 weeks, I have gone though 4 batteries that no longer take
> or hold a charge. I followed all the rules and suggestions.
>
> I just returned from the local hobby shop with two new ones, put them
> on the charger till it stopped blinking which was only a few minutes.
>
> I am now using a timer set at 5 minutes and stopped flying the first
> one when the timer went off.
>
> I did the same with the second new one but after less than two
> minutes, the led on board started flashing and the heli came down.
>
> These are all batteries with the Eflite sticker on them but no clue of
> the brand.
>
> So, am I the only one with this sort of experience?
>
> All all batteries equal?
>
> Are there better batteries out their?
>
> Thanks,
>
> Jack
have you bent a shaft or crashed it?

--
Kevin R
Reply address works

[Hasina75]

jack> I have had more than 35 cycles on mine without a problem. I never wait for the LVC to blink before I land the mCX. The voltage of the fully charged battery should be 4.18 to 4.2 volts. Then, the LVC starts to blink when the pack voltage is 3.2 volts. But, I usually stop flying when it is 3.8 to be safe even if the pack still has enough power to let you fly around. I usually use a voltmeter to monitor the flight pack voltage.


I do not use the 4 alkaline batteries to power up the charger. Instead, I use a 6V 1amp power source. Horizon hobby claims that the included alkaline batteries can power up the charger up to 15 cycles. However, I noticed that they did not charge the flight pack at full capacity after the 8th cycle (charge). After that cycle, the flight pack can not be fully charged anymore, but you still expect the flight time to be same as the first cycle by using full throttle to keep the mCx hovering around. Then, you ruin the 3.7 V lithium battery because it can not be fully charged after the 8th cycle. This happens to many mCX's owners.

Also, a poor throttle management can cause damage to the lithium battery! Horizon claims that the mCx can be flown for about 6 to 8 minutes on a fully charged battery, but "8 minutes" doesn't mean you fly it nonstop for 8 minutes. I hover the mCX for about 25 seconds; land it and take 10 sec break, and fly it for another 25 to 35 seconds; land it and take a short brake before I take off again....and so on. Then, I stop flying when the pack voltage is 3.8 volts. The stock lithium battery will last longer if you some throttle management when you fly the mCX !!!

[Chuck]

One of the bigger problems I had with Lipos turned out to be the cheap
chargers sold with many of the RTFs.
As a result, I bought a good charger/discharger/cycler unit, knowing that it
would be needed when I graduated to larger choppers. The small number of
flights you are getting and the short duration makes me think that the
charger may be the culprit. (assuming everything else is ok.) Multiple
batteries with the same problem is another clue.

"Jack Schmidling" <jack@schmidling.com> wrote in message
news:5e8c476d-8b6a-44fc-ad8b-8c2a751a8a4f@v38g2000yqb.googlegroups.com...
> In about 3 weeks, I have gone though 4 batteries that no longer take
> or hold a charge. I followed all the rules and suggestions.
>
> I just returned from the local hobby shop with two new ones, put them
> on the charger till it stopped blinking which was only a few minutes.
>
> I am now using a timer set at 5 minutes and stopped flying the first
> one when the timer went off.
>
> I did the same with the second new one but after less than two
> minutes, the led on board started flashing and the heli came down.
>
> These are all batteries with the Eflite sticker on them but no clue of
> the brand.
>
> So, am I the only one with this sort of experience?
>
> All all batteries equal?
>
> Are there better batteries out their?
>
> Thanks,
>
> Jack

[brianrees005@gmail.com]

On Dec 8 2008, 9:05=A0am, "Chuck" <cdknos...@cox.net> wrote:
> One of the bigger problems I had with Lipos turned out to be the cheap
> chargers sold with many of the RTFs.
> As a result, I bought a good charger/discharger/cycler unit, knowing that=
it
> would be needed when I graduated to larger choppers. The small number of
> flights you are getting and the short duration makes me think that the
> charger may be the culprit. (assuming everything else is ok.) Multiple
> batteries with the same problem is another clue.
>
> "Jack Schmidling" <j...@schmidling.com> wrote in message
>
> news:5e8c476d-8b6a-44fc-ad8b-8c2a751a8a4f@v38g2000yqb.googlegroups.com...
>
> > In about 3 weeks, I have gone though 4 batteries that no longer take
> > or hold a charge. I followed all the rules and suggestions.
>
> > I just returned from the local hobby shop with two new ones, put them
> > on the charger till it stopped blinking which was only a few minutes.
>
> > I am now using a timer set at 5 minutes and stopped flying the first
> > one when the timer went off.
>
> > I did the same with the second new one but after less than two
> > minutes, the led on board started flashing and the heli came down.
>
> > These are all batteries with the Eflite sticker on them but no clue of
> > the brand.
>
> > So, am I the only one with this sort of experience?
>
> > All all batteries equal?
>
> > Are there better batteries out their?
>
> > Thanks,
>
> > Jack

I'm not sure what you guys are doing to your batteries, but I've used
my one battery that came with my MCX for more than 2 months now. The
number of cycles my 110mAh LiPo battery has been through is probably
in the range of 30-50. At this point, my flight time has remained the
same as it was when the battery was new.

If you are concerned about the rate of charge for this LiPo battery,
you can easily modify your charger to either charge slower or faster.
The standard charge time for this charger is around 30 minutes (2C). I
found a link to modifying the charger by googling "MCX battery mod".
It should show up within the first few results. The forum shows that
if you open up your charger, play with the POT inside it by either
rotating it CW or CCW you can make the charge time faster or slower,
respectively.

Check the charge of the batteries inside the charger.

It should take 30-40 minutes to fully charge the battery if it is
fully discharged.

Not all batteries are created equal, but most of the time they are
when made by the same manufacturer and are from the same batch.

If you aren't satisfied with your batteries I'd recommend you bringing
them back to the store and tell them to see for themselves with a
floor model MCX and charger.

[TeraHurtz]

Check your batteries in the charger it self. I moded my charger for wall power.
Make sure your lipos charge up to 4.2V - 4.5V if not then your charger is cutting out at a lower level.

[Doug McLaren]

On 2009-01-18, TeraHurtz <TeraHurtz.3m6wkn@rcgroups.com> wrote:

| Check your batteries in the charger it self. I moded my charger for wall
| power.
| Make sure your lipos charge up to 4.2V - 4.5V if not then your charger
| is cutting out at a lower level.

They should not charge up past 4.2 volts/cell. If they do, they're
damaging the battery.

--
Doug McLaren, dougmc@frenzied.us
The Constitution may not be perfect, but it's better than what we have now.