The best timer battery?

[Neil]

Ok... I honestly have no idea where questions about batteries go (maybe propulsion, maybe ground support, maybe mid or high power cause its going in a large rocket, who knows...), so ill just put it here and let the mods move it if they are really really bored and want to do some thread moving

So I got that Perfectflite timer... so I am all happy, glad it came, amazed at how small it is, how many features its got and all that... So then I read through the installation and use instructions... It lists like a dozen different batteries you could use!!! It sounds like they think the little battery packs with the little mini batteries clustered to gether work best...

But they list 4 or 5 of those! Which ones best? And, if yer feeling extra-nice today, D) you could give me a Radio Shack part number... (/feels hopefull ) And, some background information on those battery packs (rechargable vs non recharbable, if they even make such a thing) wouldent hurt either...

This is for firing a Daveyfire 28B ematch for main chute ejection, BTW.

I have been testing some BP charges in a big flat pile of sand (email me for kewl videos and pics ) in our backyard (my grandmother is moving in this week, and we are having a new septic tank put in.... It also makes a good place to test stuff), using Estes ignitors and an Estes controller... How reliable are Estes ignitors for this kind of thing? I was making charges by pouring a few grams of BP into a corner of a plastic baggie, sticking an Estes igniter in there, hooking it up to a modified Estes controller (chopped off the alligator clips. They were getting too rusty to work anways), threading it through the hole I drilled in the top CR so I could fit charges through from the electronics bay to where the chute is, and pressed the button. THe first 4 tests worked fine, but a lot of the charge was leaking out the back. So I stuffed a nomex heat shield up there, made a new charge with 3/4 as much BP, and pressed the button... The nomex shot out of the back like a cannon, and the nosecone shot off with a boom, and everything came out cleanly. I think I may have figured out how much BP is neccesary...

Anyways, is it possible to use Estes ignitors for lighting BP charges (with some spare wire for leads), or should I stick to ematches? (this is all for future reference, btw. My dad just ordered 10 N28Bs for me today)

So, any and all information on ematches and what batteries are best to set them off would be helpfull.

Thanks in advance!

 

[BlueNinja]

The daveyfires are probably more reliable, use those.

 

[jetra2]

This should go in the Support and Recovery forum, Neil.

Also, I've heard of using 9v batteries w/ adapater for timers and/or altimeters.

Jason

 

[Austin]

Neil,

For the Perfectflite, a standard 9v Alkaline Battery would be just fine for lighting e-matches like Daveyfires. For high current ignitors though, I use the 9 Volt Nicad that is offered from Perfectflite.

It is around $15 and is rechargeable of course and is made from top quality Sanyo cells that are welded for strength. Moreover, I have seen it stand up to three ignitors on a single timer; the Nicads are much better than the Nimh's at producing the high current necessary to fire ignitors.

So far I have had 100% success with my timer and my friend who owns four or five will swear by them. He has always had successful airstarts of his HPR motors, which is why he uses them.

Cya,

Carl

 

[Missileman]

For testing you can use anything you want but for flight use ematches. I use Oxrals myself.
9v batteries are fine but don't buy the elcheapo ones, I use Duracell plus.
If you want to go the extra mile Perfectflite has "Special" rechargable batteries made specifically for rocketry electronics on their website.

 

[shockwaveriderz]

and if 9v batteries are way too much weight for what you have in mind, consider using 2 4.7 FARAD super caps in series as the battery source......4-5 grams tops.....and will fire an estes igniter...

https://www.cooperet.com/products_supercapacitors.asp

availble both at www.mouser.com and www.digikey.com