Battery suggestions for Eggfinder mini

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Jan 1, 2013
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I would like some suggestions on what brand battery everyone is using for their eggfinder. I dont trust the one I bought off ebay. Brand names and links would be helpful. Thanks.
I buy Hobby King every time.

I have had a couple puff up after flights, so keep an eye on that. I think it is the quick change in altitude that gets them. If they go puffy, throw them out.
You have to be patient in buying them, and check back occasionally. They were in stock a week ago, and now they are happens. They are great batteries for our applications.
Hey guys, another question. Can I use this charger that I got with my ebay batteries for the nanotech?

Hey guys, another question. Can I use this charger that I got with my ebay batteries for the nanotech?

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You probably can, but it's better to get something that allows you to adjust the current and allows you to monitor the voltages. I have a Turnigy P606, they're about $35 from HK, it will handle 1S-6S cells and you can charge multiple batteries of the same type simultaneously, up to 6S (i.e. three 2S 350 mAH batteries). It's also AC/DC, a big plus if you want to top off your batteries in the field.
That charger is on backorder, darn. I feel overwhelmed looking at chargers. My head hurts.
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I also use the Imax B6 charger, seems to work well and has every feature you could want. Looks like Hobbyking has a better price than I paid on Amazon but be careful if the price is too low, apparently there are a lot of cheap knockoffs that don't work or won't last.

Listen to Jeff and the good Doctor. Remember if going to store the lipos for any length of time to put it on the "storage" cycle of the charger and take them out of storage every 6 to 8 weeks of "non-use" and put them on the "storage" cycle until you need to use them. When that time comes, juice it up all the way to use it. If you over discharge a lipo, it's toast and forget it. Time to buy new. The 300mah cell should be good for one or two flights. It depends if there is going to be a long wait on the pad before launch and how long it takes to get the thing back. If you have the space and need ballast use a much larger capacity cell and you won't sweat it.
I had a 40minute wait on the pad at MWP 13 but I had a 1500mah 7.4V lipo feeding an EggFinder TRS. I didn't worry and took me 45 minutes to traipse out to the rocket. Ran for a couple of hours before I could get it turned off and the battery was fine.
If you are at a launch where you are going to have a long wait with the 300mah pack turned on, I'd start to show some concern after 30 minutes. If it's an easy
recovery, ok, but if the recovery takes awhile you don't want to run out of battery. Kurt
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An Eggfinder TX draws about 70 mA on average, so a 350 mAH battery should last about 5 hours. I've had some pretty long recoveries (like one that drifted 5 miles away...), and I've never run a battery down. 1500 mAH is really nice, if you got the space and can afford the weight... it will run for a whole weekend of flying, and then some.
An Eggfinder TX draws about 70 mA on average, so a 350 mAH battery should last about 5 hours.

Do you know how much power is drawn when an Openlogger is attached to an Eggfinder. I've done a couple of test and it appears the logger draws more juice (which makes sense since data is being continuously written to SD card).
According to a NXP blog that I found on the subject, uSD cards typically use about 30 mA. They use a little more when they're writing (up to 100 mA) but the duty cycle on the Eggfinder is only about 10%. The actual OpenLog probably uses only a few mA, it's basically just an Atmel ATMEGA328P and a few support components. I've also read that it's highly vendor-dependent... some cards go into a low-power state if they're not accessed within a certain amount of time. I'll do some testing with the cards that I have (they're from different vendors, I have a Sandisk and a Lexar) and let you know what I find.
The illusive LiPo of choice referenced above is in stock at the HobbyKing International Warehouse:

I just picked up 10 of them for $60 with shipping...I'm unwilling to wait for them to become in stock at the US warehouse to save a few $ on shipping.

I realize it is poor form to post the same thing in many threads, but I know people like these so I'm getting it out there...Also, works in my sleds too, so a bit of shameless promotion to it I guess.
Well, I got impatient and ordered one from Amazon a few days ago. Thanks for the heads up.

Edit: Damn, I paid $14 shipped for one through Amazon.
Went ahead and ordered a Turnigy 405 charger. Not the fanciest model I guess but it looks way better than the one that came with my ebay batteries.
So THAT'S why I had such a hard time getting some of those little batteries. :D

I ordered 4 this morning. If I had known they were popular here I would have let people know.
Remember, if a rocket needs ballast, you can't go wrong with using "usefull" ballast in the form of a heavier battery to supply power to a tracker. (That is of course if you have room in said rocket for it!) Kurt
Bump to this thread.
I have some 600mAh 1S lipo batteries that I have been using with a newly assembled Eggfinder mini. It seems to work fine for a basic functional test around the house.
Is there any concerns with using a 1S instead of 2S? Lower range or runtime? I don't know where the voltage cutoff is.

I also tried the same battery on the deployment power of an Eggfiner TRS and it would NOT fire e-matches, so those definitely need the 2S.
For small 2s lipos, you can get lipos in the standard “9v” package now that work great. These are usually in the 500mah range.

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Since this thread has been resurrected, the currently shipping version of the Eggfinder Mini (C3) WILL work with a 1S battery, or with a 2S battery. Theoretically a 1S should be half the size of a 2S... and weight too, plus there's no balance connector to deal with.
Well I'll add that I used the 300mA-Hr Turngy 2s on the GPS mini for three flights this past Saturday. I left it on (battery connected) between flights which totaled about 3 hours. The GPS mini used half the battery capacity in that time.

If you have a extended time for the recovery then extra battery capacity may be desired.