New Batteries 123 cells also called M1

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Lee Liddle
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New Batteries 123 cells also called M1

Post by Lee Liddle »

As they relate to 3696: I hooked up a 3s pac ,fully charged to 10.8V, to the 2908 motor with the new style MA9/6 prop. Good news Cajun. It started off at 9.5k pulling 25amps, but within about 20 to 30 seconds leveled off to 8.9k and 22amps. These numbers are great for 3696. Also I did not have to "dial down" the rates on the Tx. Both the subtrim and EPA were both at 100%. The temp at testing was about 35 degrees. IN warmer temps I think that the numbers will even be better.
Lee Liddle
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Post by Lee Liddle »

There is a ton of info about these cells on RC Groups, but I`ll start this thread and try to give you guys the Readers Digest version as it relates to combat. I will also use this to document testing that I do as it relates to the various events.

Basics: Weight 70g per cell
2300 mah
Useful voltage range 3.6 to 2.5
Size Dia 1" Length 2.5"
Deliver about 2.8v under load
Discharge rate up to 30c
Charge rate up to 10a, maybe higher
Solid aluminum "can" case

Here`s a detailed write-up on making a 123 pack
http://www.rcgroups.com/forums/showthread.php?t=587606


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The cheapest way to buy these right now is to buy battery packs for the 36V Dewalt power tools. Each pack has 10 cells in it and is easy to take apart if you have a Torex #10 tamper proof driver. This is a regular Torex bit with a hole in the middle of it. These packs retail for about $180, but can be bought on Ebay for arround $100, sometimes less. They have been out for less than a year, so I would expect prices to drop significantly over the next year or so. They can also be bought from a company called 123 Racing for about $15 each. The cells in the Dewalt packs have tabs on them. The cells from 123 Racing can be bought with or without tabs.

Positives as it relates to Combat:

Hard case, not as easily damaged from crashes.
High discharge rates can allow more power for shorter run times without the expense of High C rated lipos.
Inexpensive, about 10 to 12 dollars per cell at this time
Fast charge rates, can be fully charged in 15 min or less
1000 to 2000 charge cycles (ten times higher than lipos)
Very little heat build up with charge/discharge

Negitives

Need a different charger (should only be charged to 3.6v) can be charged to 4.2 with shorter lifespan as a result, but it does not instantly ruin batteries. There is an adapter being sold for about $40 which will allow the use of a lipo charger to charge these cells.

Heavier for less voltage.
....3s 2000mah lipo weighs about 5.5oz....about 11v under load
....3s 2300mah 123`s weigh about 7.5oz..... about 8.3v under load

However you can run the 123`s at 30c (aprox 60amps) to produce about 400 watts. While even 20c lipos (very expensive) could only produce about 200 watts. So if you have the right motor you can get the same, or more, power from the 123`s as you can a lipo.
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Ed Kettler
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Post by Ed Kettler »

Great writeup Lee!
slam
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Post by slam »

lee, you mention an adapter for the chargers, i haven't heard this......more info please.

great write up. i met a rc boat racer that was really impressed with these cells. apparently the U.S. navy is heavily experimenting with them.

these batteries as related to other uses are difficult to get your head around, they only have one size, so the application has to be right to use them. e36 seems like it might work, open b is not as likely to work. ssc is also very questionable.

keep us informed of your experimentation

slam
Lee Liddle
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Post by Lee Liddle »

Lee Liddle
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Post by Lee Liddle »

For SSC it may take a 3s2p pack to deliver full power for the entire heat. The pack would weigh about 15oz which is about 4oz more than the 3s2p2000 lipos that I`m using now. But with much greater durability, quicker charge times, safer operation, and 10 times the expected number of charge cycles, these deserve a close look. There is also another LiOn based cell, I`ll get the info, that is a 1200mah and weighs 40g. These could be put together in a 3s3p pac that would weigh 360g (12.75oz), and should be enough power to do a heat of SSC.


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These other cells are called , Saphion. They come in the Bosch tool batteries. THere are 20 cells per pack and are hooked up 10s2p. THe performance of a 2p Saphion cell and a 1p 123 cell is very similar. The Saphion cells would just give more flexability as far as MAH capacity goes for fine tuning the batt to meet the desired power/weight ballance.
Lee Liddle
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Post by Lee Liddle »

For Open 2548 I`m thinking about an 8s pack or 4s2p which would weigh 20oz. It would deliver 22v at 27a, or 11v at 54a for 5 min. This would be 600w. It will take at least 10 cells for Open B.

These are weight penelties compared to Lipos, but if E vs IC combat is to be a long term option, it`s something that will have to be factored in by the pilot. Otherwise you`ll be looking at replacing $100 or more worth of lipos after every hard midair or dirt nap.
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Post by Lee Liddle »

I`ve added more info to the top of the thread, so check it out.
Cajun
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Post by Cajun »

Good stuff Lee. Thanks[8D]

I have spent over 8 hours this week researching an alternate battery to li-Pos, as I have made the decision to purchase no more Li-Pos. It seems there are about five new cell compounds in various stages of development that look promising, but for our uses the A123 looks the best as it is already in production and available. The others are still in various stages of development and not yet in production. That means they are a year or more down the road.

If the price comes down on the A123s, as I expect it will, and all of the claims prove to be accurate, these cells should surpass Li-Pos for most of our needs. When the life of the cells (1000+ cycles vs. 200 or less cycles) is factored in, the A123s are comparable in price to Li-Pos right now. BUT, they are both expensive. Reading the battery sections of R/C Groups and Wattflyer I see too many posts of guys getting degraded performance from Li-Pos after just 30-40-50 cycles.

All of the reading I have done this week proves to me we are in a period of rapidly escalating research and development in battery technology. Hopefully our hobby will benefit from some of these new technologies.[:p]
Lee Liddle
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Post by Lee Liddle »

I`ve checked Ebay, and there are two sellers with "buy now" prices of about $100. That`s $10 per cell and $30 for a batt that is strong and long lasting. If you factor in the lifespan, the cost is about 1/8th of lipos. They are also more likely to make it to the end of that life, without getting smashed.
Lee Liddle
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Post by Lee Liddle »

This is a link for an article on how to convert an Astroflight 109 Lithium charger into an M1 charger for about $5. Looks pretty easy, I`m going to give it a go.

http://www.rcgroups.com/forums/showthread.php?t=602445
Cajun
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Post by Cajun »

Anyone know of a mod for the Triton? [?]
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Which_way_is_up
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Post by Which_way_is_up »

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Cajun</i>
<br />Anyone know of a mod for the Triton? [?]
<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">

There's a good possibility, but it depends on whether the Triton uses the simple voltage divider resistor circuit or newer technology in the form of a DAC circuit that can't be as easily hacked. I may have to open my Triton and take a peek.
Cajun
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Post by Cajun »

Roy, I'd take a look into mine, but I wouldn't have the faintest idea of what I was looking at or for[:(]

I have four chargers already and sure would like to utilize one of them.
Lee Liddle
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Post by Lee Liddle »

Did you look at this adapter Cajun?
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