Go Back  RCU Forums > RC Boats > RC Boats General Discussion
Reload this Page >

Rechargeable Batts for TX

Notices
RC Boats General Discussion Discuss general rc boating topics here.

Rechargeable Batts for TX

Old 02-15-2009, 07:39 PM
  #1  
t00fatt
Senior Member
Thread Starter
 
t00fatt's Avatar
 
Join Date: Aug 2008
Location: Miami, FL
Posts: 258
Likes: 0
Received 0 Likes on 0 Posts
Default Rechargeable Batts for TX

I went to my LHS to pick up a futaba TX charger for my magnum 2pl radio. After talking to the owner a bit I asked him which are the best rechargeable to use, and he said to get Ni-Cad AAs, and not nihms. I went to several stores, but all the rechargeable batteries I can find are nihms. Are there even Ni-Cad rechargeable AAs? What is bad about nihms, only a few cycles?
Old 02-15-2009, 07:44 PM
  #2  
guver
Senior Member
My Feedback: (325)
 
Join Date: Mar 2003
Location: LaGrange, OH
Posts: 14,857
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Rechargeable Batts for TX

Sanyo may still make the yellow 700 mah nicads which last many cycles with no degredation. Most users use nimh now which are more prone to damage,reduced capacity,ect.
Neat thing is that even if the nimh loses half of it's capacity (2000+ mah) it'll still outdo the nicad. The latest greatest thing on market for AA is probably the newest hybrid nimh cells at about 2000 mah which do not lose capacity and do not self discharge nearly as fast as regular nimh cells.
Try sanyo eneloops.
Old 02-15-2009, 08:47 PM
  #3  
t00fatt
Senior Member
Thread Starter
 
t00fatt's Avatar
 
Join Date: Aug 2008
Location: Miami, FL
Posts: 258
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Rechargeable Batts for TX

Are the sanyo eneloops the hybrid nihms? I don't mind replacing the batteries every couple of months, roughly how many cycles are the regular nihms getting?
Old 02-15-2009, 08:51 PM
  #4  
guver
Senior Member
My Feedback: (325)
 
Join Date: Mar 2003
Location: LaGrange, OH
Posts: 14,857
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Rechargeable Batts for TX

Yes, they are. I have no idea how many cycles a nimh can go.
Old 02-16-2009, 12:16 AM
  #5  
t00fatt
Senior Member
Thread Starter
 
t00fatt's Avatar
 
Join Date: Aug 2008
Location: Miami, FL
Posts: 258
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Rechargeable Batts for TX

Thanks for the help, I appreciate it!
Old 02-16-2009, 07:08 AM
  #6  
mfr02
 
Join Date: Jul 2007
Location: Blackpool Lancs, UNITED KINGDOM
Posts: 1,432
Likes: 0
Received 32 Likes on 32 Posts
Default RE: Rechargeable Batts for TX


ORIGINAL: t00fatt

I went to my LHS to pick up a futaba TX charger for my magnum 2pl radio. After talking to the owner a bit I asked him which are the best rechargeable to use, and he said to get Ni-Cad AAs, and not nihms. I went to several stores, but all the rechargeable batteries I can find are nihms. Are there even Ni-Cad rechargeable AAs? What is bad about nihms, only a few cycles?
I feel your LHS may need to do a bit of learning about batteries. In a TX, NiMH is pretty much ideal. Mine are into their 3rd season, no sign of any problems. Actual capacity has more than trebled over NiCads, result is longer sailing time before the red light comes on, downside is that using the same charger, it takes longer to charge them up, but as I trickle charge anyway, I have yet to notice a problem with wanting to sail before a full charge is indicated.
Old 02-16-2009, 06:20 PM
  #7  
Justaddwata
My Feedback: (3)
 
Justaddwata's Avatar
 
Join Date: Feb 2005
Location: RI-USA, RI
Posts: 6,160
Received 9 Likes on 9 Posts
Default RE: Rechargeable Batts for TX

If a model comes with Nicads - I throw them out - wont even chance it.

I usually buy AA's in bulk every year or so - you can usually find deals on e-bay for 60 x 2400mah or more AA's for under a buck a piece. I use them for photography as well so tend to go through them. Not sure I would ever test the 1000 recharge warranty - not sure it is worth your model trying for $1 each.
Old 02-17-2009, 08:31 AM
  #8  
lownslo
Senior Member
 
lownslo's Avatar
 
Join Date: Jan 2002
Location: Indianapolis, IN
Posts: 996
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Rechargeable Batts for TX

I must say I am far from an expert on batteries. (But I did stay at Holiday Inn Express last night). This guy IS an expert, and he is right here on RCU, AMA magizine, and over 5000 postings on RCU. His name is Red Scholefield.
http://www.rcuniverse.com/forum/sear...mitbutton=+OK+
WOW! what a long URL. He also has a web site of his own called "The RC Battery Clinic".
http://www.rcbatteryclinic.com/
I have been into RC Aircraft since 2000 and am just getting into boats. I did learn most all of the things I know from his Battery Clinic site and his postings. I TRUST what he says.
Personally...... I like to charge my NiMH packs with a peak charger. I have had great results with NiMH, but do NOT overcharge. Overheating by overcharging will evidentually kill the capacity. Read his stuff and be more battery wise. You won't regret it.
lownslo...... Bob in Indy
Old 02-19-2009, 11:50 PM
  #9  
jetpack
My Feedback: (1)
 
jetpack's Avatar
 
Join Date: Oct 2002
Location: Hobart, IN
Posts: 2,477
Likes: 0
Received 2 Likes on 2 Posts
Default RE: Rechargeable Batts for TX

One thing I've noticed with rechargable batteries verses dry cells is the voltage.

Dry cells are all rated at 1.5V and the rechargables are 1.2V - 1.3V.

Add up eight batteries and with rechargables you are down on voltage by one or two whole cells.

You would have to add more rechargable cells to bring up the rated voltage to what the TX is designed to run on, 12V.

All the capacity doesn't help much if the voltage doesnt match, and if it is lower than it needs, your basically running on "dead" batteries even though they are fresh charged.

I used to have a Futaba 27mhz AM radio and it did cause problems when I ran rechargables.

I have changed to a newer Futaba FM but I bought that with factory nicad packs and have stayed with it with no voltage problems.

Reading up on this problem might shed some light on it, or give the right answer but I changed out radios and never looked into it more.

You know, thinking back now...I remember passing through one of my radio instruction books and in the warnings that nobody really reads I seen it had said "use only dry cell batteries" and now it dawned on me this is probably the reason why. I didn't really acknowlege why at the time and forgot about it. Does anyone else remember maybe seeing this too?
Old 02-20-2009, 08:47 AM
  #10  
Tony Fitzpatrick
Senior Member
 
Join Date: Feb 2009
Location: cowtown, UNITED KINGDOM
Posts: 101
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Rechargeable Batts for TX

ORIGINAL: jetpack

...I remember passing through one of my radio instruction books and in the warnings that nobody really reads I seen it had said "use only dry cell batteries" and now it dawned on me this is probably the reason why. I didn't really acknowlege why at the time and forgot about it. Does anyone else remember maybe seeing this too?
Yes, but include NiMH and NiCD and alkaline as dry cells.It means don't use wet-cell lead acid batteries.
or keep posting that on a few more model boat forums to start your very own urban myth.

To answer t00fatt's question.I personally don't care for the original owner's advice or anything third hand info.Go look up manufacturer and industry databases and see for yourself.
Use 2.4 NiMHs

Tony Fitzpatrick
Old 02-20-2009, 10:02 AM
  #11  
lownslo
Senior Member
 
lownslo's Avatar
 
Join Date: Jan 2002
Location: Indianapolis, IN
Posts: 996
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Rechargeable Batts for TX

Hmmmmmm
What is 2.4 NiMH ????? Never heard those 2 descriptions used together. There are the 2.4 gHz radios, or two- 1.2 volt NiMH cells for a total of 2.4 volts, but the 2.4 volts would not apply to the post by t00fatt. I am not familar with t00fatt's radio, a magnum 2pl. Maybe that is why I don't understand.
lownslo
Old 02-20-2009, 10:16 AM
  #12  
Tony Fitzpatrick
Senior Member
 
Join Date: Feb 2009
Location: cowtown, UNITED KINGDOM
Posts: 101
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Rechargeable Batts for TX


ORIGINAL: lownslo

Hmmmmmm
What is 2.4 NiMH ????? Never heard those 2 descriptions used together. There are the 2.4 gHz radios, or two- 1.2 volt NiMH cells for a total of 2.4 volts, but the 2.4 volts would not apply to the post by t00fatt. I am not familar with t00fatt's radio, a magnum 2pl. Maybe that is why I don't understand.
lownslo
I hate it when folk use acronyms on forums.
I'll leave you to guess or google it though.
Old 02-20-2009, 10:30 AM
  #13  
jetpack
My Feedback: (1)
 
jetpack's Avatar
 
Join Date: Oct 2002
Location: Hobart, IN
Posts: 2,477
Likes: 0
Received 2 Likes on 2 Posts
Default RE: Rechargeable Batts for TX

Here tOOfat,

I found a screenshot of your instructions and I'll explain what I mean about voltage.

Rechargables usually only carry 1.2V.

If you stack 8 cells with this voltage, your pack will only put out 9.6 volts.

The instructions tell you not to use the transmitter below 9 volts, so that only means you have just about only a 1/2 of volt safety margin, so it won't take very long for your transmitter to use up that 1/2 of volt, then your done and you should stop using it, and recharge. That means bad range and your TX won't be trusty.

The only way to get around this problem is to add more cells externally to bring up the voltage to what the TX is designed to operate on, which is 12V with 1.5V dry cells.

If you use high-capacity rechargables, you might be able to get away with using them because they will hang at 9.6V for a long time, but you're still using the TX with a risk of clunking out on you.

Not sure if you want to go through the expense of finding this out buying rechargables or not, maybe borrow a set first to see what happens, or go by other peoples experience.

I just know that mine struggled with it.

Attached Thumbnails Click image for larger version

Name:	Sq46601.jpg
Views:	10
Size:	46.7 KB
ID:	1140342   Click image for larger version

Name:	By76652.jpg
Views:	15
Size:	31.6 KB
ID:	1140343  
Old 02-20-2009, 10:33 AM
  #14  
lownslo
Senior Member
 
lownslo's Avatar
 
Join Date: Jan 2002
Location: Indianapolis, IN
Posts: 996
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Rechargeable Batts for TX

Well Tony Old Boy,
Why would you reply like that. This forum is to help people. From your answer/reply, I am taking it as sarcasim. If it is , you are contributing NOTHING to this forum, or to t00fatt. I still don't know what you are talking about. Do you?
Why tell me to guess or Google it. Google what? His radio, 2.4, or ????
lownslo
PS. Try to answer nicely. My reply above ..... I am not blasting you. I really want to know what you mean.
Old 02-20-2009, 10:40 AM
  #15  
jetpack
My Feedback: (1)
 
jetpack's Avatar
 
Join Date: Oct 2002
Location: Hobart, IN
Posts: 2,477
Likes: 0
Received 2 Likes on 2 Posts
Default RE: Rechargeable Batts for TX

Yes, please dispell this "urban myth", I would like to know also.[>:]
Attached Thumbnails Click image for larger version

Name:	Mk27600.jpg
Views:	10
Size:	19.7 KB
ID:	1140347  
Old 02-20-2009, 11:08 AM
  #16  
Tony Fitzpatrick
Senior Member
 
Join Date: Feb 2009
Location: cowtown, UNITED KINGDOM
Posts: 101
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Rechargeable Batts for TX

Likewise lownslo.
Like I said,I hate having to read posts over and over to understand acronyms.
Hydride batteries now come in the same capacity as long life alkaline types at 2.4 amp hours.

I just got 451 Google hits for "2.4 NiMH" and saw your post at #5

jetpack,you can claim to be the original author of the urban myth that Futaba specify single-use cells for their transmitters if it takes off.I'm all for it.

When Futaba say use "dry cells" it inclides rechargeable cells.
Some manufacturers specify further to use only rechargeable types and not single use batteries in receivers.
When the cells are heavily loaded or have been partially discharged the voltage of rechargeable types exceeds the equivalent capacity alkaline type.They have a power rating of several times that of alkaline.
When you use two or more standard servos alkaline batteries just can't cope with with the current surges as the internal resistance is too high.

Tony
Old 02-20-2009, 12:32 PM
  #17  
lownslo
Senior Member
 
lownslo's Avatar
 
Join Date: Jan 2002
Location: Indianapolis, IN
Posts: 996
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Rechargeable Batts for TX

AH Hah!! This makes sense now. Thanks for clearing that up. The original statement was missing the "amp hours" after the 2.4. With new transmitters at 2.4 gHz, and two NiMH cells equaling 2.4 volts I got off track.
I do agree with using rechargeables. I have had 5 radios while in RC airplanes and NEVER had problems with the rechargeables. I switched to NiMH packs on my last 2 transmitters with 1650 mAh. Those will fly airplanes or run boats for hours. Again.......
NiMH are more senitive to heat/overcharge. Use a PEAK charger.
NOTE: Futaba, maybe others, have a diode, (I am NOT good at electronics), but that will create problems or won't let a charger like a Triton and others, READ the battery. It won't charge if I am not mistaken. Others can probably explain better. I spliced in an extra male plug, tucked it in under the lid and now I charge battery with only removing the lid...... NOT unplugging and taking out the whole battery.
Attached Thumbnails Click image for larger version

Name:	Pn36351.jpg
Views:	9
Size:	26.3 KB
ID:	1140388  
Old 02-20-2009, 12:53 PM
  #18  
danielplace
 
Join Date: Dec 2008
Location: Ocala, Fl
Posts: 689
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Rechargeable Batts for TX

ORIGINAL: Starkbone McGarvey

ORIGINAL: jetpack

...I remember passing through one of my radio instruction books and in the warnings that nobody really reads I seen it had said "use only dry cell batteries" and now it dawned on me this is probably the reason why. I didn't really acknowlege why at the time and forgot about it. Does anyone else remember maybe seeing this too?
Yes, but include NiMH and NiCD and alkaline as dry cells.It means don't use wet-cell lead acid batteries.
or keep posting that on a few more model boat forums to start your very own urban myth.

To answer t00fatt's question.I personally don't care for the original owner's advice or anything third hand info.Go look up manufacturer and industry databases and see for yourself.
Use 2.4 NiMHs

Tony Fitzpatrick
Actually it does mean dry cell as in alkaline batteries. Certainly not the lead acid batteries you talk about this is crazy why would they tell you not to use something that doesn't even exist that would go in the radio in the first place.
They have designed the radio to run on eight 1.5 volt cells for a total of 12 volts. Actually if you wired a remote 12 lead acid or gell cell it would last for a week without any issues. Because the smallest available is usually about 4 amp hour or 4000 milliamp. Thats a lot.
Rechargables are 1.2 volts each for a total of 9.6 volts. So right off you are low on voltage and will drop below the 8.5 rrequired very shortly. But I have found the precharged NiMh duracells
work great despite this and are comparable to the enolope cells. Not reg duracell nimh but the precharged. Walmart has them and there is no comparison to the old style.
They actually hold a charge.
Old 02-20-2009, 01:43 PM
  #19  
guver
Senior Member
My Feedback: (325)
 
Join Date: Mar 2003
Location: LaGrange, OH
Posts: 14,857
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Rechargeable Batts for TX

Nimh batts are nearly empty at 1.2 volts. It is a nominal reading. Charge them up first

I thought most of us used rechargeables
Old 02-20-2009, 02:42 PM
  #20  
Tony Fitzpatrick
Senior Member
 
Join Date: Feb 2009
Location: cowtown, UNITED KINGDOM
Posts: 101
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Rechargeable Batts for TX

And for those who don't now Alkaline cells are empty at 0.9 depending on discharge rate
[link]http://www.mpoweruk.com/performance.htm[/link]
Lookat the discharge voltage graph and compare.
At greater than the C/5 rate the difference between alkaline and NiMH,NiCD is pretty stark and the capacity of alkaline has to be derated.

In short,that is why I said to t00fat......
ORIGINAL: Starkbone McGarvey
To answer t00fatt's question.I personally don't care for the original owner's advice or anything third hand info.Go look up manufacturer and industry databases and see for yourself.
Use 2.4 NiMHs
Tony Fitzpatrick
Old 02-20-2009, 02:57 PM
  #21  
Tony Fitzpatrick
Senior Member
 
Join Date: Feb 2009
Location: cowtown, UNITED KINGDOM
Posts: 101
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Rechargeable Batts for TX

[link]http://en.wikipedia.org/wiki/Dry_cell[/link]
[link]http://en.wikipedia.org/wiki/Wet_cell[/link]
Old 02-20-2009, 04:25 PM
  #22  
danielplace
 
Join Date: Dec 2008
Location: Ocala, Fl
Posts: 689
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Rechargeable Batts for TX

ORIGINAL: Starkbone McGarvey

[link]http://en.wikipedia.org/wiki/Dry_cell[/link]
[link]http://en.wikipedia.org/wiki/Wet_cell[/link]
Do you have a link where I could buy some AA wet cells. Didn't think so. I just think they want your voltage up around 12 volts to start with. Wet cells have 2 volts per cell
also so that would end up at 16 volts for 8. I smell smoke.
Certainly not trying to start anything. I should not have used that crazy word. It sounded like an attack. I have have great luck with the rechargables provided you charge
them just prior to use. Have a good one.

Daniel
Old 02-20-2009, 04:37 PM
  #23  
lownslo
Senior Member
 
lownslo's Avatar
 
Join Date: Jan 2002
Location: Indianapolis, IN
Posts: 996
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Rechargeable Batts for TX

You are all forgetting something. Go back to my post #17 and #8. The lower voltage is only the RESULT of LACK of mAh, (milliamp hours). The current draw will deplete the stored volts. Notice......(in post#17) my pack is 1650 mAh. Then read "The Battery Clinic" from the link I had in post #8. I admit I am not up on the new chemistry. I will guarantee you that if I put in my 1650mAh, AA, NiMH pack, and you use 8 Duracell AA, or a pack made from 8, AA-NiCDS, I will be "playing at the pond a looooong time after you head for home to charge up".
Old 02-20-2009, 04:57 PM
  #24  
Tony Fitzpatrick
Senior Member
 
Join Date: Feb 2009
Location: cowtown, UNITED KINGDOM
Posts: 101
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Rechargeable Batts for TX

No offence was taken.
If it is of any consequence,it is the younger generation who use dry/wet in another context but the issue is safety.They mean cells which can't leak.Some alkaline and other primary cells do leak when left in while later ones don't.

I found some info on the Futaba failsafe which is interesting.
Google "cannot endure a large current draw" and look at the failsafe battery requirement.
http://www.futaba.com.au/images/INST...UALS/FSU1_.pdf

Futaba get their instructions wrong anyway.
http://www3.omnimodels.com/cgi-bin/w...I=FUTL0354&P=0
The typo in the comments paragraph has been reproduced several times over.It should match with the failsafe.

That is no concession.
http://www.batteryrecycling.com/Battery+Reference+Guide
http://www.teachervision.fen.com/tv/...rencies_14.pdf
Old 02-21-2009, 12:34 AM
  #25  
danielplace
 
Join Date: Dec 2008
Location: Ocala, Fl
Posts: 689
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Rechargeable Batts for TX

ORIGINAL: lownslo

You are all forgetting something. Go back to my post #17 and #8. The lower voltage is only the RESULT of LACK of mAh, (milliamp hours). The current draw will deplete the stored volts. Notice......(in post#17) my pack is 1650 mAh. Then read "The Battery Clinic" from the link I had in post #8. I admit I am not up on the new chemistry. I will guarantee you that if I put in my 1650mAh, AA, NiMH pack, and you use 8 Duracell AA, or a pack made from 8, AA-NiCDS, I will be "playing at the pond a looooong time after you head for home to charge up".
Just checked and the voltage does not even drop 1/10th of a volt with radio off then turned on with any dry cells or rechargeables. How many milliamps do you think a transmitter pulls?
Forget all this and get a LIPO. That is all I will ever use. It will run a 3PKS all day every Sunday for 3 months without a charge. I have started the day with 12.3 volts and leave with it reading 12.4 volts.
Makes all this reading a waste of time. JUST GET A LIPO AND BE DONE.

Thanks Daniel

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.