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        Discussion Battery in my Futaba 6EX 2.4GHz does not last long

#1 g725s Mar 04, 2012 07:44 PM

Battery in my Futaba 6EX 2.4GHz does not last long
 
I've got a new Futaba 6EX 2.4GHz with a Futaba NT8F600B 9.6V 600mAh battery that last less than 1hr transmit time. I did buy the radio from a private party but it was new and unused. It may have been sitting for awhile unused if that matters. I did leave it on overnight and through a day a few days ago, but that should not have killed the battery should it? I have only charged it twice since I got it. Both times for 15hrs as the instructions say to, once before I left it on all day and just after. But even the first time I charged it only lasted less than an hour.

I need more transmitter time!

I've researched using a 11.1V Lipo and some have said it works, and others say don't do it, that it will fry the transmitter.

Even if I can't use a Lipo, I would like to charge the Futaba NiCad quicker than the 15hrs that the wall charger requires. If I have to pull the battery out regularly to charge it faster, I'd like to get an extension for the battery wire that plugs to the transmitter, so I'd not be pulling the connection off the transmiter PCB pins all the time. This plug is a Futaba servo type, but with only two wires installed + & -. I'd need a battery charger cable that has banana plugs and this Futaba servo style connector.

Or possibly I could just leave the battery in the transmitter and use a plug (not sure the plug type name) like the one that you can actually plug into the transmitter for charging from the wall charger. But if I fast charge the 9.6v NiCad @ 60mA for 5hrs will it get too hot in the transmitter?

#2 Wrend Mar 04, 2012 08:01 PM

Probably your best option is to get some Eneloops or a pack made out of them. Here's a mini-review I did on using them in my 6EX: http://www.rcgroups.com/forums/showthread.php?t=1078898

They'll take quite a bit longer to do a full charge with the stock charger because they have about 4 times the capacity of the stock NiCd pack, but since they don't self discharge at a significant rate and can last for 12+ hours on one charge, you're not likely to need to do a full (from empty) charge on them anyway.

Also not a good idea to leave your TX on, and yes it could have possible done some damage to your pack if the cells in it are out of balance. Still not as bad as leaving your TX on with a LiPo pack in it...

#3 DougV Mar 04, 2012 08:33 PM

You probably using half the capacity from that pack, recycle it a few times.

Doug.

#4 g725s Mar 04, 2012 08:42 PM

Quote:

Originally Posted by Wrend (Post 20938314)
Probably your best option is to get some Eneloops or a pack made out of them. Here's a mini-review I did on using them in my 6EX: http://www.rcgroups.com/forums/showthread.php?t=1078898

They'll take quite a bit longer to do a full charge with the stock charger because they have about 4 times the capacity of the stock NiCd pack, but since they don't self discharge at a significant rate and can last for 12+ hours on one charge, you're not likely to need to do a full (from empty) charge on them anyway.

Also not a good idea to leave your TX on, and yes it could have possible done some damage to your pack if the cells in it are out of balance. Still not as bad as leaving your TX on with a LiPo pack in it...

It looks as if your putting in your 6EX nearly 11.5V initially with this setup. In my google search today I read quite a few post mixed with the people using the 11.1V Lipo, where people say that the 11.1V Lipo is too much voltage for the 6EX. What are your thoughts on this?

#5 g725s Mar 04, 2012 08:44 PM

Quote:

Originally Posted by DougV (Post 20938593)
You probably using half the capacity from that pack, recycle it a few times.
Doug.

I will. I need to get a battery charger cable with the Futaba male and banana plug to my charger. Thanks!

#6 Jim.Thompson Mar 04, 2012 09:03 PM

Discharge to 1 volt per cell (8 volts for the pack) when cylcing.
You will be surprised at the gradual improvement in capacity after 2 o 3 cycles.
Unless you have irretriveably damaged you cells.

Jim.

#7 Wrend Mar 04, 2012 09:04 PM

Quote:

Originally Posted by g725s (Post 20938662)
It looks as if your putting in your 6EX nearly 11.5V initially with this setup. In my google search today I read quite a few post mixed with the people using the 11.1V Lipo, where people say that the 11.1V Lipo is too much voltage for the 6EX. What are your thoughts on this?

Full 3S LiPo is 12.6V. The fully charged Eneloops are close to fully charged NiCd and shouldn't be a problem.

#8 g725s Mar 04, 2012 09:57 PM

Quote:

Originally Posted by Wrend (Post 20938314)
Probably your best option is to get some Eneloops or a pack made out of them. Here's a mini-review I did on using them in my 6EX: http://www.rcgroups.com/forums/showthread.php?t=1078898

They'll take quite a bit longer to do a full charge with the stock charger because they have about 4 times the capacity of the stock NiCd pack, but since they don't self discharge at a significant rate and can last for 12+ hours on one charge, you're not likely to need to do a full (from empty) charge on them anyway.

Also not a good idea to leave your TX on, and yes it could have possible done some damage to your pack if the cells in it are out of balance. Still not as bad as leaving your TX on with a LiPo pack in it...

Wrend, are you still using those battery circuit springs that you installed into your 6EX to accept individual AA's? You mentioned in that post you linked above that you were worried about possibly losing power from the batteries not seating well. Did you every experience that problem?

Not sure I'd go that route as it seems a fair bit of work tracking down some springs and installing them. But it is a great idea.

I do like the idea of having a pack made from these Eneloops though, if I could find a company that will do that.

Edit: Found this site: http://www.cheapbatterypacks.com/pro...lat--Pack.aspx Thanks for the ideas!

#9 g725s Mar 06, 2012 11:28 PM

Quote:

Originally Posted by Jimbello (Post 20938827)
Discharge to 1 volt per cell (8 volts for the pack) when cylcing.
You will be surprised at the gradual improvement in capacity after 2 o 3 cycles.
Unless you have irretriveably damaged you cells.

Jim.

I will do this Jim. Thanks for the advice!

#10 Wrend Mar 07, 2012 04:55 AM

Quote:

Originally Posted by g725s (Post 20939242)
Wrend, are you still using those battery circuit springs that you installed into your 6EX to accept individual AA's? You mentioned in that post you linked above that you were worried about possibly losing power from the batteries not seating well. Did you every experience that problem?

Not sure I'd go that route as it seems a fair bit of work tracking down some springs and installing them. But it is a great idea.

I do like the idea of having a pack made from these Eneloops though, if I could find a company that will do that.

Edit: Found this site: http://www.cheapbatterypacks.com/pro...lat--Pack.aspx Thanks for the ideas!

The main radio I use these days is my 8FG (and unfortunately AA cells don't fit in it, so I can't use Eneloops with it). I never had any issues with the "loose" cells in the 6EX.

If you don't mind paying the extra cost for it, I would recommend getting a well made Eneloop pack instead of using the loose cells though, just for the added peace of mind.

Stock charger works fine, by the way. Just put the TX on it overnight (and take it off in the morning) when the voltage drops down below 10V, and you should be good to go for the next time you want to use your 6EX without having to wait for it to charge.

#11 Jim.Thompson Mar 07, 2012 02:28 PM

Quote:

Originally Posted by Wrend (Post 20963070)
...............................
If you don't mind paying the extra cost for it, I would recommend getting a well made Eneloop pack instead of using the loose cells though, just for the added peace of mind.

Stock charger works fine, by the way. Just put the TX on it overnight (and take it off in the morning) when the voltage drops down below 10V, and you should be good to go for the next time you want to use your 6EX without having to wait for it to charge.

Personally, I would not charge good cells like Enneloops (maybe the very best?) with anything else but a modern "smart" peak Dv charger. I would prefer to have something cheaper well maintained than the best money can buy less than well maintained.
I've had very good success with the HobbyKing low self discharge cells which are incredibly cheap. However, I initialise them with a very slow charge and then condition them with 3 cycles. Then maintain them by charging with only my Dv peak charger. Cycle every couple of months or so when I remember to do so, regardless of wether I have flown the plane or not.

There are some very good battery tips on this site:
http://www.hangtimes.com/rcbattery_faq.html
Worth the read.

Jim.

#12 Wrend Mar 07, 2012 06:18 PM

Like I said, the stock charger is perfectly fine for Eneloops, and actually likely better for them than a -ΔV peak charger as long as they're not just left on the charger indefinitely to continuously overcharge. This also lets the cells balance at a fuller charged state if slightly overcharged, and is a more ideal way to charge cells in series. (-ΔV overcharges cells slightly too, only at a faster rate, and without allowing the cells to balance as well as they would otherwise; and just hope that you don't get a missed termination.)

You can tell when they're done charging when they start to warm up slightly, but you don't have to completely charge them each time either. Charging overnight when the pack drops below 10V is fine.

The stock charger charges at such a low rate (70mA) that it is not an issue whatsoever.

If it's any consolation, the first generation Eneloop cells I used in my 6EX almost 3 years ago now have only lost about 1.1% of their capacity potential (using the IEC capacity measurement standard) from when they were new, and they are still within the typical capacity variation range of new Eneloop cells.

Hope that clears things up. :)

#13 Daedalus66 Mar 07, 2012 06:54 PM

Quote:

Originally Posted by Wrend (Post 20969195)
Like I said, the stock charger is perfectly fine for Eneloops, and actually likely better for them than a -ΔV peak charger as long as they're not just left on the charger indefinitely to continuously overcharge. This also lets the cells balance at a fuller charged state if slightly overcharged, and is a more ideal way to charge cells in series. (-ΔV overcharges cells slightly too, only at a faster rate, and without allowing the cells to balance as well as they would otherwise; and just hope that you don't get a missed termination.)

You can tell when they're done charging when they start to warm up slightly, but you don't have to completely charge them each time either. Charging overnight when the pack drops below 10V is fine.

The stock charger charges at such a low rate (70mA) that it is not an issue whatsoever.

If it's any consolation, the first generation Eneloop cells I used in my 6EX almost 3 years ago now have only lost about 1.1% of their capacity potential (using the IEC capacity measurement standard) from when they were new, and they are still within the normal capacity variation range of new Eneloop cells.

Hope that clears things up. :)

Similar experience here with Eneloops and stock JR charger. No problem.


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