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Old Jul 02, 2001, 09:48 PM
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Edmonton, Alberta, Canada
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Everyready NiMH 9v == Energizer 9V NiMH

I checked the charged voltages and both were the same and after disecting they contain the same cells (same manufacturer and stamping). I've soldered up a 7 cell pack from these two batteries now to test. I'm hopefull this will work with the litestick. If it is still a bit short on power I may try adding another cell for a 8 cell NiMH pack.
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Old Jul 03, 2001, 11:04 AM
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Walled Lake, MI, USA
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I'm a little confused here at what points you are trying to make. I thought the only rechargeable NiMH 9V battery Eveready made was the Energizer ACCU. Are you saying that you have an Energizer ACCU 9V and a different-looking Eveready 9V?

Also, it clearly states on the Energizer battery specs that the ACCU 9V is 7.2V (6 cells). Are you saying that you are soldering up 7-cell packs by taking cells from 2 Energizer 9V batteries? This seems like a lot of work when the Rayovac 9V (8.4V) battery has 7 cells that are already connected. Do you believe that the Energizer cells are superior to the Rayovac cells, making it worth the effort to solder your own packs?

From my experience, Lite Stik performance is a little weak on the 7-cell Rayovac, and the Rayovac cells are not easy to work with to create a custom 8-cell pack. If the individual Energizer 9V cells are easier to create custom packs with, then you may be on to something with an 8-cell pack that would fly a Lite Stik with more authority. You could make 3 8-cell packs out of 4 9V Energizers.

Please post lots of details about this intriguing experiment!
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Old Jul 03, 2001, 05:20 PM
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It has been too windy to fly, but I couldn't/can't find rayovac 9v NiMH cells locally. I had found the accu 9v NiMH which is 6 cells. I later spotted a cheaper bright yellow EVERREADY labeled 9v NiMH that was very sparse in any documentation about capacity, voltage etc. I picked it up and upon taking it apart noticed the cells were the same. The cells are spot welded with thin metal strips between each cell, and the cells are stacked vertically. It is quite easy to pop them apart and remove the metal stripping and solder up packs out of them as usually one solder joint is needed (more for the left over 2 cells to be joined). If a 7 cell rayovac is a little weak, I should probably add an 8'th cell to this pack before trying it out. I'll do some bench tests and see what comes of it. I know these cells cannot dump the amps nearly as good as 110 nicads can, but hopefully the litestick motor won't draw enough that it is too noticable.
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Old Jul 03, 2001, 06:41 PM
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Charging the 8 cell pack now. I tried the 7 cell, and the power was roughly equivalent to 6 nicads. Good weight/power, but not enough raw juice for strong climbs so I added an 8'th cell.
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Old Jul 03, 2001, 06:56 PM
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Excellent information. Sounds like the Energizer ACCU may be more marketing hype than technology if the less expensive Eveready contains identical cells. Your description of the Eveready cells sounds similar to the Rayovac cells, which are little rectangular "sandwiches" encased in a clear plastic sheath under the metal exterior.

I haven't bothered to fool with individual Rayovac cells because someone posted a message here a few months ago saying that when he took the plastic sheath off, the cells basically fell apart. It sounds as if the Eveready cells are a little more robust.

All of this talk about 9V batteries did get me to stop at a True Value Hardware store this afternoon and pick up my first GE/Sanyo 9V NiCd. I just have this uncontrollable urge to rip 9V batteries apart and see what's inside! ;-)
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Old Jul 03, 2001, 11:10 PM
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The energizer/everready cells are oval with a blue vent seal on the neg side. Each one is clearly stamped + on one side and they are quite sealed individually. Still too windy to test fly the stick on 8 NiMH :/ the power was better than 7 on the ground for sure, but still seems a bit shy of 7 110's.
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Old Jul 04, 2001, 11:03 PM
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After doing a full charge, and then full throttle on the stik for a bit, it seems like I get maybe 1-2 minutes of full power before the bec kicks in on the speed control with these cells. Something obviously isn't working right (charger or cells) The 8 cell pack was reporting about 11.5 volts 30 seconds after coming off the charger.
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Old Jul 04, 2001, 11:22 PM
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Here is my 2c since I found the rayovacs at a walmart store and bought 2 + a charger recently.

Charged one 9v at the recommended slow 10-12 hour rate so not much info yet. The other I charged at 300ma for 30 minutes. I've run through 4 cycles of the battery using the "semi-quick" charge rate and here are my results direct wiring the 9 volt to the motor. My arbitrary cutoff point for timing was based on running the plane until the tail is no longer held off the bench by propwash.
1st charge - 3min 5sec
2nd charge - 3min 30sec
3rd cahrge - 3min 35 sec
4th charge - 4 mmin 5 sec

If I end up with a 5 min run time after a few more cycles, I will be happy since these batteries are cheap ($6.95) and light. My seat of the pants thrust comparison to the GWS 6cell 270mah pack is the rayovacs start out stronger for the first couple minutes, equal for the next minute and taper off from there. BTW, I get about 8min 30sec on my 6 cell 270s using the same test.
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Old Jul 05, 2001, 01:02 PM
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A quick tip for those using 9v batteries: don't ever carry one in your pocket if you have loose change, keys, etc. I did and shorted out the battery which got very very hot. I'm discarding the battery and leaned a good lesson. Always cover the battery ends to protect against shorts. I bought several 9v clip on wire sets at radio shack so now I will use them to shield the battery leads during transport. BTW, the 9v rayovac 150ma nimh weighs 1.5oz compared to 2.7oz for the GWS 6 cell 270ma nicad pack.
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Old Jul 05, 2001, 08:37 PM
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So far, no one seems to have had any luck with any of the Eveready 9V batteries. If it won't work with 8 cells wired together, maybe it's just a case of the individual cells not being up to the job.

There is an intriguing new 9V NiMH battery that has apparently just hit the market. Batteries America is showing a new 9V from AP, the LX8, that is rated at 200mAh and sells for $8.50. Check the link below and scroll all the way to the bottom.

Interestingly enough, if you then scroll up to the AP NiMH cells above the 9V, there is also a new AP AAAA NiMH cell, the AP-200 TA, also rated at 200mAh and selling for $2.95 each. It may just be a coincidence that they came out at the same time, or could this new AP 9V contain 6 of the AAAA cells? If so, this could be a very hot deal as long as the cells are up to 1.5A discharge rates.

http://www.batteriesamerica.com/newpage3.htm
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Old Jul 06, 2001, 08:03 PM
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I'm interested in LX8 info if anyone has tried that one yet. 150mah is good but 200mah would be even better if weight is about the same.

Update on Rayovac 9volt (8.4v actually)
Charge #5 4min 40sec
charge #6 4min 35sec

I also tested my second battery which has only been charged with the rayovac charger. It has had basically the same performance as my quick charger. I realize Cx2 charging may decrease the life of the battery but at $7/each, who cares. I'll be happy with 100 charges and I bet I get more than that.

I also did a test charge hooking up the battery to the ESC, servos with throttle at full to see when the esc cuts out. Cut off at 4min 20sec compared to 4min 40sec wired direct to motor and using my prop wash test.

Since timed charging for 30 minutes at a fixed 300ma and 9volts doesn't heat up the battery at all, I've started experimenting with higher charging times (35min last time) which could be contributing to the longer run times. My goal is 5 minutes before BEC trips and I think I will make it. I'll post results if (when) I get there.
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Old Jul 06, 2001, 10:22 PM
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The LX8 200mAh 9V is right at 1.5 oz. The 200mAh AAAA cells are about .2 oz. each.
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Old Jul 07, 2001, 07:46 PM
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Dave, please share your experience with this cell if you have already bought them. I've been researching the rayovac 9v and just made a major milestone of exceeding 5 minutes (5min 55sec) before the BEC cut the motor out. However, 200ma cell should perform even better if all else is equal.

Quote:
Originally posted by Dave Hederich:
The LX8 200mAh 9V is right at 1.5 oz. The 200mAh AAAA cells are about .2 oz. each.
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Old Jul 07, 2001, 08:21 PM
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The Varta nimh has 7 oval coin cells. Looks like you could take them apart pretty easily. Rated at 150mah. I haven't done any performance testing. Anyone use these?
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Old Jul 07, 2001, 10:56 PM
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I do not have any of the new NiMH APs. I already have more new "stuff" to experiment with than I can handle right now. I just posted the information in case there was someone out there looking for new NiMH cells to play with.
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