STEP-BY-STEP guide on how to build a $12 TX battery! - Page 3 - RC Groups
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May 13, 2003, 02:59 PM
Registered User
This thread is worth bumping up to the top again. Excellent idea, eparkflyer.

While it may not be likely that the cells would shift enough in the cell holder to cut power while you're flying, here's a simple little insurance policy: Just wrap a layer or two of tape around each of the two 4-cell "clusters." Alternatively, you can use a couple of strong rubber bands. Either will effectively lock the cells in place in the cell holder.
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May 13, 2003, 05:09 PM
Registered User
I couldn't find any of these batteries at the nearest Big Lots but found an 8x700 NiCd R/C Car pack for $4-5 on sale at ToysRUs. I got some spare 9V connectors from RS. I took the flat pack apart and made a block pack for my Tx (Hitec Flash 5X) and soldered on the 9V connector. I have also soldered a 9V connector to the Tx and some banana plugs to another.

I can now charge the pack in the Tx on the wall wart charger, or remove it from the Tx and peak charge it on the Triton even at the field. My solution isn't as simple as above but it works and changing packs is a breeze.

Precautions needed:
1. remove the wires from one 9V connector and clip it on the spare pack to prevent unpleasant surprises once the connector touches metal in your pack storage box/case/bag/pocket. The connectors are cheap at RS, so do it for evey spare pack.
2. Make sure the +ve lead from the pack eventually makes it to the right connector in the Tx.
May 13, 2003, 07:27 PM
Registered User
Stopped at a Radio Shack on the way home and picked up one of the AA 8-cell holders. Topped off 8 of the Panasonic AA NiMH cells I'd picked up at a Big Lots a couple of months ago and inserted them. When I pushed the loaded cell holder into the transmitter, it was a tight, tight fit. Turned on the transmitter and shook it really hard in every which direction trying to make the green "on" light blink. No problem.

I wouldn't even bother trying to use tape or rubber bands. The tight fit that keeps the holder and cells from moving inside the transmitter really allows no room for tape or rubber bands anyway.

I wouldn't give up on this just because you can't find the Panasonics on sale at Big Lots. Really, for transmitter use you don't need cells that will handle >10A like the Panasonics. Just about any decent AA NiMH cells that you can find on sale anywhere would work in this application. This is really a fantastic package.
May 15, 2003, 09:09 AM
Registered User
First flights with the new transmitter battery pack resulted in zero problems. This is really an inexpensive, simple solution for improving transmitter battery pack performance.
May 15, 2003, 11:35 AM
Registered User
SheldonYoung's Avatar
A ready-made 8 cell pack of Sanyo 1650 mAh NiMh with a connector from most vendors is about $25 US. It IS worth the extra $13 for the piece of mind of a high quality pack and not having to run around the country looking for bargain cells.

If you do decide to go the do-it-yourself route be aware the quality of the plastic holders varies an incredible amount.
May 15, 2003, 05:24 PM
Registered User
Well guys, for what it's worth, I did this conversion to my JR about two years ago, altho my pack is soldered I can tell you that it has been well worth the trouble. I can go to a weekend flyin and only charge once, the night before.
A little tip, NImH cells do not like to be left in a discharged condition, charge it up as soon as you get home
Robert.
Last edited by RMFISH; Jun 17, 2003 at 04:50 PM.
May 15, 2003, 05:45 PM
Registered User
SheldonYoung's Avatar
Agreed. I cannot understand why new radios still use 600 mAh NiCds.
May 19, 2003, 09:04 AM
Registered User
>> It IS worth the extra $13 for the piece of mind of a high quality pack and not having to run around the country looking for bargain cells.

For some people. Others like to tinker and hunt for bargains. My peace of mind is just fine.
May 19, 2003, 01:06 PM
Mark Imbriaco
I'll agree with Dave on this one. I did a lot of research and finally decided to buy an Eclipse a few weeks ago. While I was waiting for it to arrive I went to RadioShack and bought one of the holders and popped in 8 generic 1800 mAh AA cells that I had lying around.

I did the shake test and empirical flight testing and I haven't had the first problem. This is a great solution for someone looking for an inexpensive solution that will give you a whole lot more capacity than the stock battery pack.
Jun 17, 2003, 03:18 PM
Registered User
I have been using this system of eight AA nimh cells in the radioshack holder for about 3 years now and have never had a problem. I just recharge them with the stock wallwart charger. Best Buys is selling 1800 mah cells pretty cheap. Anybody want to buy 2 nicad tx packs, nib?
Nov 07, 2003, 01:05 PM
Registered User
About time for the 6-month update: Have had no problems with this setup in 6 months of flying. It may not be for everyone, but I still recommend it as a good option.
Nov 07, 2003, 02:47 PM
Cho Oi! Hay Qua!
tomi's Avatar
eparkflyer: You must live in the ghetto or something. Our biglots are all clean. Just like a regular store.

Has anyone tried this on a Futaba radio? wait no their battery bed is flat. I'll just have to solder the batteries together for full contact.
May 19, 2004, 01:10 PM
Registered User
Another 6-month update: I've been using this setup for just over a year now, and have not had a single problem.
May 21, 2004, 03:25 AM
Always right
Hovertime's Avatar
Whats interesting and may be convenient-looks like Hitec planned on using this battery holder? Flash 4/5 (i think) has contacts in the battery compartment so you just drop it in? (my flash 4 is at hitec for repairs, so i don't remember for sure,) can somebody confirm this?
Is it drop in for other hitec radios too? looks like so from pics at #7 #8 posts here, what about Eclipse 7?
Oct 02, 2007, 02:50 PM
Registered User
RTHawk's Avatar
DAVE: Any problems yet?