Re: Battery Pack Building

Why make your own packs?? Go to radicalrc.com. Great prices and $2
shipping on any order. You probably can't make them for what you can buy
them for and then you have to worry about whether you made them properly.
John VB
Reply to
jjvb
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Dale- Have you got something special in mind? If you need standard 4 or 5 cell Rx packs, it really isn't worth the bother to make them up. As an example, you can get 4 ea Sanyo 600AE cells from Cermark for $9.00, plus a battery pigtail/connector @ $2.50, and your DIY battery kit costs $11.50. Or you can pay them $12.00 for a ready made pack. How much of your time is worth 50 cents?
Abel
Reply to
Abel Pranger
| Have you got something special in mind? If you need standard 4 or 5 | cell Rx packs, it really isn't worth the bother to make them up. As | an example, you can get 4 ea Sanyo 600AE cells from Cermark for $9.00, | plus a battery pigtail/connector @ $2.50, and your DIY battery kit | costs $11.50. Or you can pay them $12.00 for a ready made pack. How | much of your time is worth 50 cents?
I disagree.
Home Depot sells 4 pack 800 mAh AA NiCds for $5.00. Wal Mart sells 4 pack 900 mAh AA NiCds for $5.17. (In both cases, they're meant for use with and are found with the solar powered yard lights.) Or you can buy 1800 mAh AA NiMH cells from mcmelectronics.com for $0.85 each (search for 58-7740.)
You can save a good deal of money, even off of radicalrc.com prices, by making your own packs, especially if you want NiMH cells. radicalrc.com will charge you $14 for a 4 cell 1650 NiMH receiver pack with no connector. Or order cells from mcmelectronics.com for it for $3.40.
Reply to
Doug McLaren
You can also check cell phone packs. Stores often put them on sale, especially when a phone is going OOP. I've picked up 4 cell, 600 mah packs for around $5. Even the 3 cell packs are worth it. Buy 4 and you got a RX and TX pack both.
Dr.1 Driver "There's a Hun in the sun!"
Reply to
Dr1Driver
Go right ahead and use those consumer grade batteries and best of luck to you. Most of them are fine for their intended use but CRAP for our use.
Reply to
jeboba
| Go right ahead and use those consumer grade batteries and best of luck to | you. Most of them are fine for their intended use but CRAP for our use.
I've been using them for a while and have not found them to be `CRAP' for my use. I assume you have some evidence that these batteries are `CRAP' ?
Especially for your transmitter packs, why would I want to pay $18 for a 700 mAh pack from radicalrc.com or $70 to srbatteries.com for a 1100 mAh pack, when I can make my own 900 mAh NiCd pack for $11 or 1800 mAh NiMH pack for $7?
I've not been impressed with the consumer batteries for power packs (the internal resistance of AA and AAA cells of all sorts are usually too high) except for slow park fliers, but for receiver packs they work very well, and for transmitter packs they are *excellent*.
Especially since I've been putting two packs into my 0.40 and larger glow planes, I feel just fine with the consumer batteries. (Of course, I've had no crashes that I attribute to battery failure, `consumer grade' or not. I also cycle my packs occasionally to measure their condition, and at $4 or $7 I'm much more willing to replace old packs early than I am at $30 or $70.)
Reply to
Doug McLaren
Like you really believe battery manufacturers make special batteries for the R/C trade? Horsehockey!
Wanna buy some lowland in Florida? Kinda damp but stilts should work.
I've used "consumer grade" batteries for over 15 years with NO complaints. Competition Fun Fly, sport, giant scale.
Dr.1 Driver "There's a Hun in the sun!"
Reply to
Dr1Driver
Evidently, Doug, you realize how the cosmos works. :) Lots of $$$ in a "brand name" label, or inflated, slanted, loaded specs. Dr.1 Driver "There's a Hun in the sun!"
Reply to
Dr1Driver
I believe it was Popular Science a while back had an article on rechargeable batteries. If I remember correctly there are only 6 companies around the world that make Nicads and their kin, the process is so environmentally unfriendly. I also recall there are several "grades" I think, of batteries made. Thus the price difference.
Personally I spend a little money on my packs, both those bought and ready made. Having spent many an hour building an aircraft, I don`t mind. To me it`s the old Bell helmet advertisement. Got a $10 head, wear a $10 helment. rick markel
Reply to
Aileron37
Having worked for one of the 6 (the largest at the time) I can tell you that we made only one "grade" of cell. So did our major competitors . Sanyo, Saft, Panasonic, Gould* and Marathon. If you go now to the Sanyo spec page or Panasonic I think you will be hard pressed to see where there are different grades. Cells for different applications - high temperature, memory back up, high rate, high capacity - yes, but from a quality standpoint they are all the same "grade". Even the "aerospace cells" touted by one assembler are actually stock commercial cells that have gone through extensive testing to "qualify" them for aerospace according to NASA test protocols, but this testing does nothing to the basic cell - other than take it a ways down the wearout path. :-)
*
no longer in business as a Ni-Cd manufacturer.
At one time when the demand for NiCd exceeded the supply and customers were put on allocation cells that failed customer specs found their way into the "consumer" pipe line. But as processes became refined the fallout that did not make spec. became insignificant. As production caught up to demand it was not unusual for an occasional order to be cancelled due to a variety of business reasons. Packs already built were torn down (Mexican labor is inexpensive compared to the cost of materials in a cell) and used in a variety of applications where the cosmetic signs of rework would not be noticed or of a concern.
New manufacturers on the block include Gold Peak and a number of other come-lately Chinese manufacturers of questionable quality. Some battery manufacturers (who do not manfuacture Ni-Cds) are brokering these cells to and selling as consumber cells under their label.
Red S. Red's R/C Battery Clinic
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rechargeable
Reply to
Red Scholefield
For the do it yourself group, check you local battery recycling bin. We did a study when this first started and found that about 75% of the battery packs turned in were perfectly OK. Bad charger, customer did not understand them, broken welds, fractured cases or other assembly flaws . . . but the cells themselves were perfectly good. If you watch the date codes you can get some very serviceable cells well within acceptable use time frames. -- Red S. Red's R/C Battery Clinic
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Reply to
Red Scholefield
Rick,
7 years with proper care is about the mean time to failure - half will make it this far the other half will not. You got the lucky half.
The cells are not matched in an SR pack, they come that way from the Sanyo factory as their process control is excellent - with all cells in a production batch well within limits that are better than any matching* process.
*
a means for justification of exorbitant price for a battery pack while providing no real value.
If you have had packs go belly up in a month or so you have been on the other - unlucky half. How long were they in the hobby shop before you bought them? Or did you get some bargain stuff from some salvage operation? I have had one bad cell in the hundreds of factory new Sanyo's that I've run through the battery clinic. I have also had one S&R pack that a customer brought in that had a shorted cell when received. I took the opportunity to do a tear down one of the other cells in the pack. It had a lot of unformed material indicating that it was never cycled as it would have to have been if matched. They replaced it with no hassle. I have packs (GE) that are 10 years old (stored in the refrigerator) that still give rated capacity when checked.
Bottom line - make sure your supplier is using Sanyo cells and knows how to weld the straps. Fly with confidence from there on.
Red S. Red's R/C Battery Clinic
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----- Original Message ----- From: "Aileron37" Newsgroups: rec.models.rc.air Sent: Thursday, August 07, 2003 8:10 PM Subject: Re: Battery Pack Building
Reply to
Red Scholefield

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