Space saving LiPo alternatives to 9v?

Hey everyone!

I have been curious about powering altimeters with LiPo batteries, and was looking to see who has some experience with them. I'm not neccessarily looking to save weight, but saving space is a major plus! I know that the RRC3 is rated between 3.5v and 10.0v. So If I were to drop a 5v LiPo in the e-bay with leads to the RRC3 terminals, would all go swell? Is it that simple?



Braden

I have flown some cheap hobby king Lipos for a payload requiring alot of power, However not for an altimeter. I think most people have been reluctant to use them because of the risk of a lithium fire (as if a rocket motor isn't enough hazard right?) Although I had recently stumbled upon a video and or photos of a fire started from a team digging their rocket out of the ground and striking a battery causing a fire, I am going through my web history trying to locate it. Aside from the battery, the connectors on some of the RC hobby battery's make excellent on off switches

I know very little about the use of LiPos in rockets, but I think you would need some additional circuitry to regulate the current released, if they were used to ignite anything, like another motor or an ejection charge. The reason for this is that LiPos can be destroyed or damaged if they release their charge too quickly (or if they are charged too quickly). This is also one of the ways in which they can catch fire.
I thought LiPos would be a great way to light a cluster reliably because of their ability to release large amounts of current at once, but it turns out that it isn't that simple. Also, be mindful of the fire risk. This is a big consideration of RC pilots, and it should be of any rocketeer using the same equipment.

Having said all of that, because of the dangers that these batteries pose, each one has very specific limits on draw and charge rates, as well as a specific output, and this information should be printed on the battery itself. So if you know about electronics, you could easily build something that would be safe with minimal components and, overall, I think it could work really well, and would definitely reduce the weight and size of your rocket. And with the fire stuff, thousands or RC pilots use LiPos safely everyday, so if you take the time to understand the risks they pose, go for it!

Using a very small single-cell lipo works just fine as long as the altimeter uses a capacitor to supply the firing current, or uses a capacitor to prevent brownout. You are more likely to burn out a FET switch on the altimeter than the battery.

I've crashed a 400 mAh lipo into the ground pretty catastrophically (lake stake) and it didn't catch fire despite heavy deformation. It's probably because in such a small battery, the total energy isn't enough to actually start combustion.

Braden, We had a thread on this topic at https://www.rocketryforum.com/showt...people-using-for-the-RRC3&highlight=lipo+RRC3

I am about to use mine. Patelldp has the most experience and has used 3.7 V lipo (same one used in Featherweight Ravens) with the RRC3. I am going with a 7.4 V discussed in the thread by One Bad Hawk. There is another pretty good thread somewhere. I will try to track it down.

4kids49 said:

Braden, We had a thread on this topic at https://www.rocketryforum.com/showt...people-using-for-the-RRC3&highlight=lipo+RRC3

I am about to use mine. Patelldp has the most experience and has used 3.7 V lipo (same one used in Featherweight Ravens) with the RRC3. I am going with a 7.4 V discussed in the thread by One Bad Hawk. There is another pretty good thread somewhere. I will try to track it down.

Click to expand...

Rarely do I find a thread that I get called out in...

Yes, I was one of the Beta testers for the RRC3, and I have 7-8 flights on the RRC3 utilizing the same LiPo that Adrian sells with the Raven Av-Bays. Worked flawlessly every time. My recent concern is utilizing the batteries that Chris mentions for an ARTS2, as much less is known about the circuitry of the ARTS than most other modern altimeters. My goal is also to save space, as I'd like to fit the ARTS2 and two of the 7.4V LiPo's in one of BadAzz Rocketry's 54mm altimeter bays in my Mongoose 54.

4kids49 said:

Braden, We had a thread on this topic at https://www.rocketryforum.com/showt...people-using-for-the-RRC3&highlight=lipo+RRC3

Click to expand...

After reading that discussion, I did some searching about for low C and <200 mAh rated 2S lipo than the Turnigy models from HK for use with a DDC22 as well as a future planned RRC3 purchase. Although an RRC3 is rated to work on the nominal voltage from a 1S lipo, the DDC22 is not.

https://www.valuehobby.com/power-systems/batteries/2s-lipo/20c-180mah-2s-jst.html

I ordered them early this week along with some JST extension cables (one snip to get a male and female pigtail) and they arrived yesterday by USPS 2-day. I plan to test them once we get some rain out here in CA. I expect to use the same charger mentioned in the prior thread although I ordered mine from NewEgg (shippped, still waiting for arrival).

I have been using lipo batteries with all my altimeters and I am quite happy with them. They are quite reliable and I am not affraid anymore of letting my rocket beeping away on the launch pad.
I do not have to charge them after each flight, I have done up to ten flight on one of my rocket without re-charging them.
I have a had a couple of crash and never started a fire.
The lipo batteries that I am using are
https://www.ebay.fr/itm/1-Batterie-...816?pt=FR_Image_son_Piles&hash=item2573780e78
However make sure that you get the appropriate charger
so you would be better off buying
https://www.ebay.fr/itm/2pcs-9v-Rec...936?pt=LH_DefaultDomain_0&hash=item23332456f8

bdureau said:

The lipo batteries that I am using are
https://www.ebay.fr/itm/1-Batterie-...816?pt=FR_Image_son_Piles&hash=item2573780e78

Click to expand...

The link you provided is not a LiPo battery, it is a standard Li-Ion (two very different things).

sorry I though they were the same as lipo battries
anyway those are quite good, I have been using them for years and they always fire my ematches