About Lithium Batteries in Launch box

I have a Pratt Launch box (the one that fills/dumps/ fires Hybrids). It has the battery in the bottom of the box.
Anyone use Lithium Batteries to power launch boxes?

I use 2 large 2s 35c RC batteries in series (These can put out ~175 amps continuously). You can launch anything you want all day long with these. A single smaller 4 or 3 cell Lipo pack would work great too. I’ve launched every igniter type available with this with no trouble.

Awesome!

you can start cars with these batteries, used properly I can guess you could provide enough current and voltage to light a Xmas tree

The Transolve FIREBOX has a 3 cell, 2200mAH lithium pack, plus

radio control to 300 feet range +. Rated at 15A+ output current.

www.transolve.com

I have an Estes Pro Series II launch controller with a 3S Lipo pack. I have only used it one launch day so far; no issues, launched over a dozen rockets, most BP Estes motors, one 18mm Aerotech composite and two multi launch drag races with no issues. has built in clip whip for launching multiple motors/rockets at once. probably a little less than what you need but suits me greatly.

That is made for 6 'C' alkaline batteries. You must have modified it.

I strongly recommend you add a fuse or circuit breaker to the battery.

Liths are blowing up in hoverboards and Ecigs, they are not to be treated lightly. Shorting out "may" trigger a built in protection device in the battery, but may go to hard open.

XolveJohn said:

That is made for 6 'C' alkaline batteries. You must have modified it.

I strongly recommend you add a fuse or circuit breaker to the battery.

Liths are blowing up in hoverboards and Ecigs, they are not to be treated lightly. Shorting out "may" trigger a built in protection device in the battery, but may go to hard open.

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It is made for 6 'C' Alkaline batteries or a 2/3A 8-10 cell NiMH 600-100mAh or a 3S LiPo at least 1000mAh, no modifications as it comes from the factory with JST plug. Instructions include Alternate battery usageView media item 346389

Well then Estes is dumb. A woman got $1,000,000 due to her dress getting set on fire by an E-cig while driving her car. I heard of a guy who was blinded by working on a lead acid battery in a forklift, could not see the terminals due to access problems, and put a wrench across the terminals, it blew up and spewed acid everywhere.

Anyone who uses a high current battery without over current protection is unresponsible.

It is not my place to defend Estes or not, but coming from someone who 25 minutes ago did not know that this controller was designed to use Lipo and NiMH batteries and now knows what the internal circuits and current protection can or can not do; I shall take your above comments with a grain of salt.

OK. Try shorting the clips and firing. Let me know what happens.

XolveJohn said:

OK. Try shorting the clips and firing. Let me know what happens.

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I shorted the leads with an ignitor and fired. everything went well.

No, I mean clip the clips together with no ign. A short circuit.

That could happen in actual use if they accidently touch.

Note it could blow something up. Not trying to be smart. But I have dealt with 400A battery circuits. Safety is paramount. Most liths have a thermal protection device inside, but there are a lot of cheap fake packs coming over that are dangerous. Google how many hoverboards have blown up. And cell phone/laptops. This is without shorting.

The Boeing 777 was grounded for awhile due to the giant lithium battery
going into flame mode spontaneously. Airbus actually went back to NICADS for awhile.

I hear ya on safety, but with my limited knowledge of electronics is not the point of a launcher to create a short circuit?
and I would have to continue to depress both momentary switches to continue shorting the circuit?

solid_fuel said:

I hear ya on safety, but with my limited knowledge of electronics is not the point of a launcher to create a short circuit?
and I would have to continue to depress both momentary switches to continue shorting the circuit?

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No, an igniter is not a short circuit. A short circuit is a zero (or very nearly zero) impedance path between two points on a circuit. An igniter is low, but not zero impedance and thus limits the current.

XolveJohn said:

No, I mean clip the clips together with no ign. A short circuit.
The Boeing 777 was grounded for awhile due to the giant lithium battery
going into flame mode spontaneously.

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Sorry, but that was the Boeing 787...

from a designer of a launch controller back in 1991 - Veri-Fire

A 30 amp fuse in the wiring would be highly recommended - automotive blade type would be ideal. That should be big enough to handle any igniter, but small enough to "blow" if there is a short circuit. LiPo batteries are both good and bad. They have a high energy density and the ability to dump massive amounts of current quickly. The 25C number you see on the 1000mah battery means it is capable of doing 25 times its current rating or 25 amps continuously until it runs out of energy with actually an even higher dead short current discharge for a shorter time. One I looked at was 50amps short term. What this means is if you really have a dead short, switch contacts could fuse so you can't turn it off, the next to go is any contacts or wires that have a little bit of resistance. They will heat up quickly and melt - could even catch fire. An added fuse is simply a place where the circuit can be broken safely without damaging the rest of the system.

Imagine having a 5000mah battery and that it is capable of doing a 250amp continuous flow of current - basically one of those car starter ones. Nothing wrong with using that as the battery, but not without a fuse in the system to protect everything.

I honestly don't know whether the Estes controller has a fuse or something they threw in to protect everything, but I would suggest that you take a look inside. If there is some protective circuit, then all is okay. If there isn't, you can get automotive fuse holders at a car parts store and add one to one of the two wires coming out of the controller.

Thanks Moe, and Steve! That 787 lithium pack is about as big as a dishwasher. I don't think it burned on a flight, but on the ground. Turns out the company that made the charger NEVER TRIED IT WITH AN ACTUAL BATTERY, just a load simulator. oops. They decided to make more of the motors and stuff electric instead of hydraulic, thus the giant battery. The one time they tried charging a big battery, they burned their plant down, so went with the load simulator. Doh.

I played around with electric cars back in the day, and still use the packs on electric model planes. Some lessons are hard learned. Got tired of the smell of burning circuits and flames jumping out. I prefer circuit breakers instead of fuses. But if you want to protect to 15A, use a 7A breaker, as they generally will pass twice the rated current for a few seconds, perfect for ignitors.

I use a 3s 1250 mAh LiPoly in one of my Estes PSII controllers as well as an old 3s 3200 mAh Kokam pack which originally flew my Sig Kadet LT-25 a dozen years ago to power my 3-channel launch controller.

I've been using lithium batteries in RC airplane applications for 16 years. When they are treated with respect and charged properly (preferably with a good balancing charger) they are fine. Physical damage is bad. Some cheap cells are - well I wouldn't trust them as I do the old Kokams.

I do have 20A fuses on the input to my 3-channel launch controller. We have a similar arrangement going into the club 10-channel system with which we use a 12V lead-acid garden tractor battery. In the club system, 20A would cook the wiring between the panel and the pads.

In the PSII controller the small gauge wiring to the JST connector (and from it to the circuit board) will fail long before that little 1250 mAh battery will be past it safe discharge current limits - so you could say there is a fuse or overcurrent protection of sorts....

The 787 issue was charging related as noted above. When I learned what they had done I was - well - let's just say I still don't believe how stupid that whole situation was. By then the RC community knew full well about balancing charging for quite a few years. The 787 battery is NOT "about at the size of a dishwasher" unless the dishwasher in question can handle perhaps half a dozen plates, tops. It's more like a group 27 auto battery in size. But there are two of them, one in each of the airplanes two major electrical equipment racks. The batteries in other Boeing airplanes are NiCd.

Yes, the 787's systems are more electric than other airliners as no engine bleed air is used for air conditioning or powering hydraulic pumps. It also has electric rather than hydraulic brakes.

Erring on the side of caution in my opinion is best especially if that means adding a fuse and holder which cost very little. Protects the battery and can protect you. I have worked with LIPO's for years. They can dump a lot of current. A 20amp fuse is plenty in my opinion for rocketry. I've run 10 amp fuses and launched M-N motors without any problems. The last thing I want to say is "I wish I would have..... or why didn't I ........."

In my controller I use for my rocket gliders I put an inline blade style automotive fuse holder, acts as a fuse and my removable interlock. I use a 2100 3s battery, do about 300 flights a year, charge it 2-3 times a year, only takes 300-400 in a recharge. These are with fastfire Jr igniters. The actual ignition switch is an automotive 30 amp heavy duty button that I have Velcro on and I can velcro it to the side of my xmitter. There's about 50 feet rubber covered extension cord for the launch cable.

Surprising you don't have a relay to minimize the heavy wire path from battery to launcher. Also can then use skinny wire to the launch button.

I love my Transolve FireBox. Has radio control so don't need to lay out wire to the pad. A snap to set up and take down. Plenty of power, someone fired 7 Estes ignitors in a cluster with it.

I used 6 conductor flat satin telco wire with telco connectors for my connection between the handheld launch controller and the box at the pad with a relay. Nothing like being able to lay out a few hundred feet of cable in a walk and pick it up just as fast.

SteveThatcher said:

I used 6 conductor flat satin telco wire with telco connectors for my connection between the handheld launch controller and the box at the pad with a relay. Nothing like being able to lay out a few hundred feet of cable in a walk and pick it up just as fast.

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That’s what my launchers use also. At 12 volts it doesn’t conduct well enough for a 1,000 foot run so I plan to make the next version use 48 volts to control the relays.

Steve Shannon said:

That’s what my launchers use also. At 12 volts it doesn’t conduct well enough for a 1,000 foot run so I plan to make the next version use 48 volts to control the relays.

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The relay was not directly controlled by the launch button, so I could use 2000 feet if I wanted to.

As an easy fix for what you already have, you could add a lower current relay at the pad box to turn the power relay on and off. Just a thought...

SteveThatcher said:

The relay was not directly controlled by the launch button, so I could use 2000 feet if I wanted to.

As an easy fix for what you already have, you could add a lower current relay at the pad box to turn the power relay on and off. Just a thought...

Click to expand...

Nice thought. An interposing relay makes a lot of sense. I should have thought of that. Thanks!