Launch battery recommendation….

The Rocketry Forum

Help Support The Rocketry Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

MarsLander

Well-Known Member
TRF Supporter
Joined
Oct 31, 2023
Messages
985
Reaction score
1,469
Location
Ohio
We have been using the jetski battery, and it has worked great. Need to buy a dedicated battery. Is there a type (lipo, agm etc) or size/capacity I should buy?

A-g bp and composite motors…

I have norco charger.

image.jpg
 
Sounds like your jetski battery was 12V? I've had good experiences with small lithium iron phosphate batteries. Larger ones are lightweight compared to a gel cell. If you don't want to get a different charger, some have circuitry which supposedly makes them act like lead acid 12V batteries, at least when it comes to charging. I have one that I'm going to try in my ancient electric lawn mower. Ought to save a few pounds.
 
I also use Li-Iron-Phosphate batteries. I have them for Ham Radio portable already in a few sizes.
You would only need a small one and they are very light. I have a 12V, 4.5Ah for loads that don't pull 15-20amps like a full size HF rig.

The 4.5ah can handle 9amps intermittent, like firing a rocket or Transmitting on a small VHF/UHF radio.

I bought this one before the rapid inflation so it did not cost as much as it does now. These are the best, cheaper ones are on Amazon, but don't last as long as in cycles or years.

https://www.bioennopower.com/products/12v-4-5ah-lfp-battery-pvc-pack?_pos=5&_fid=4b5510c46&_ss=c

I use the 20ah ones from them for my 100 watt Ham Portable radio that pulls 16-17 amps.
 
We use 12v gel cells like that posted by @SolarYellow for our multi-pad launch systems, one at each pad bank. I also have a 12v LiPo battery for a single pad controller. Finally, I've been using two 7.2 v NiMH batteries in my Estes Pro-Controller for decades. So pick your poison. I like the sealed lead acid batteries for their robustness, simplicity, and safety. I only use other types where weight is an issue.
 
We use 12v gel cells like that posted by @SolarYellow for our multi-pad launch systems, one at each pad bank.

One thing I've wondered about is the 6V vs 12V versions of those. The 6V is half the size and I've see it (same brand) for as low as $7. Seems like a screaming bargain. The Estes Electron Beam Launch Controller uses 4 AA batteries, so I figure the VRLA should be more than adequate. Bump it up with bigger wires, like 16GA, and it should be able to handle some reasonable clusters.

I've also seen discussion of a 12V battery providing so much current to a resistive ignitor that it basically blew it out rapidly, reducing the duration of the ignition heat to the point that reliability may have been impacted negatively.

Would be happy to see any discussion of 6V vs 12V with people who have used batteries of equivalent current capacity at both voltages. @BEC
 
One thing I've wondered about is the 6V vs 12V versions of those. The 6V is half the size and I've see it (same brand) for as low as $7. Seems like a screaming bargain. The Estes Electron Beam Launch Controller uses 4 AA batteries, so I figure the VRLA should be more than adequate. Bump it up with bigger wires, like 16GA, and it should be able to handle some reasonable clusters.

I've also seen discussion of a 12V battery providing so much current to a resistive ignitor that it basically blew it out rapidly, reducing the duration of the ignition heat to the point that reliability may have been impacted negatively.

Would be happy to see any discussion of 6V vs 12V with people who have used batteries of equivalent current capacity at both voltages. @BEC
It really depends on the igniters you're wanting to fire (and to a lesser extent the motor types you want to fire), and the current-flowing capability of the wiring. Certainly a 6V lead acid battery will do what four (good) AAs can do. I'd be a little leery of trying to cluster with 6V as the current will get high (and so the voltage will sag) with the usual parallel connections....but again it depends on the igniters.

I have mentioned that the Estes Sonic igniters, which were made for the Estes-relabeled Aerotech motors that were sold when the Pro Series II was new a decade ago were, I am told by a reliable source, made specifically to fire those motors from a 9V source as the simple and durable PSII launch controller is configured for 6 C-cells. On 12V they fired so quickly that they often didn't get the White Lightning motors lit.

There are too many variables to simply say "6V is good enough" or "12V is too much" for a general case. Personally, almost everything I use regularly uses a 3s LiPoly battery of some sort. I have one in my "just grab it to go flying" PSII controller and both the three-pad system I built for school groups and our club's 5-10 pad system are powered these days from 3s LiPoly packs. The club system, when it came into my possession, was using a Group U1 12V lead acid garden tractor battery. A 5AH 3s LiPoly is MUCH more portable.....

I think if I were starting from scratch I'd look at LiFePo packs, but I have lots of chargers for LiPolys as rockets displaced my electric RC airplanes in my life about the time lithium batteries went mainstream.

Another club I fly with uses 12V jump-starter packs to power all their GSE.
 
I have mentioned that the Estes Sonic igniters, which were made for the Estes-relabeled Aerotech motors that were sold when the Pro Series II was new a decade ago were, I am told by a reliable source, made specifically to fire those motors from a 9V source as the simple and durable PSII launch controller is configured for 6 C-cells. On 12V they fired so quickly that they often didn't get the White Lightning motors lit.

That must be what I was thinking of. Thanks for the clarity.
 
I use 3 cell 11.1 V. Lipo's from reputable dealers and a good charger. Never had a issue.
 
If 12V is too hot for some igniters, one can always use a resistor in series. I've made some of my own igniters and have seen some of the more sensitive ones fail under high voltage. A 9V alkaline isn't always 9V, because it has a fair amount of internal resistance. A
 
One thing I've wondered about is the 6V vs 12V versions of those. The 6V is half the size and I've see it (same brand) for as low as $7. Seems like a screaming bargain. The Estes Electron Beam Launch Controller uses 4 AA batteries, so I figure the VRLA should be more than adequate. Bump it up with bigger wires, like 16GA, and it should be able to handle some reasonable clusters.

I've also seen discussion of a 12V battery providing so much current to a resistive ignitor that it basically blew it out rapidly, reducing the duration of the ignition heat to the point that reliability may have been impacted negatively.

Would be happy to see any discussion of 6V vs 12V with people who have used batteries of equivalent current capacity at both voltages. @BEC
I have modified my Estes Electron Beam controller for 12V. Pretty simple. I have the plan from Sport Rocketry I could mail you .I use a motorcycle battery I carry to and from launches in a bucket. Make sure you use a 12 V bulb in the controller.
30 years and no issues.
 
Never had any issues with 12 v lead acid systems. It's easier to get good 12 v chargers, so I've stuck with those.
Ditto. I have a zillion 12V SLA batteries left over from an old UPS. Fairly cheap, plenty of umph, easy to charge. I've launched 7 motors clusters with dedicated leads using a breakout box (no parallel or series wiring of igniters) with no issue.
 
If you have battery powered hand tools, you can find battery holders with power leads for the batteries. Wire the leads into your launcher or incorporate the battery holder right into the controller and you can use your tool batteries for power.

You might need to change the LED resistors if they are a higher voltage then what your controller has now, but it's a pretty simple and reliable method. Just grab a battery out of a drill or other tool when you go to launch. You probably don't even need to charge it after, just pop it back in the drill.
 
Last edited:
If you have battery powered hand tools, you can find battery holders with power leads for the batteries. Wire the leads into your launcher or incorporate the battery holder right into the controller and you can use your tool batteries for power.

You might need to change the LED resistors if they are a higher voltage then what your controller has now, but it's a pretty simple and reliable method. Just grab a battery out of a drill or other tool when you go to launch. You probably don't even need to charge it after, just pop it back in the drill.
Or just add one of these, and a supercap, to make your controller almost omnivorous. It's possible some other little bits may be required.
https://www.digikey.com/en/products/detail/analog-devices-inc/LTM8083EY-PBF/13404960

Alternatively, use a simple current limiter instead of a resistor for the LED's.
eHDap.png
 
Launch report from this battery. Full charge with the Norco. 2 Estes ignitors and 1 Quest ignitor (D motor) worked fine. Smoked 3 quest ignitors after that...

Does that mean the battery is to powerful for the ignitors, or there is an issue with the battery being not charged. Or, is it an issue with ignitor placement? They were all the way in to the black tape. Frustrated...
 
Launch report from this battery. Full charge with the Norco. 2 Estes ignitors and 1 Quest ignitor (D motor) worked fine. Smoked 3 quest ignitors after that...

Does that mean the battery is to powerful for the ignitors, or there is an issue with the battery being not charged. Or, is it an issue with ignitor placement? They were all the way in to the black tape. Frustrated...
I use a battery like that for my DIY made launch controller. I've never had a problem with Estes ignitors. Do you have a volt-ohm meter? Check the battery voltage. A healthy lead acid battery should be around 12.7v. A few years ago when I was mentoring a rocket team at the Tribal College I worked at we received a rocket kit to put together and it came with a quest motor and ignitors. We were using an Estes hand-held launch controller and when the safety pin was inserted and the continuity check button pressed the motor ignited taking all of us by surprise. So I think the issue is the Quest ignitors and not your launch controller.
 
It really depends on the igniters you're wanting to fire (and to a lesser extent the motor types you want to fire), and the current-flowing capability of the wiring. Certainly a 6V lead acid battery will do what four (good) AAs can do. I'd be a little leery of trying to cluster with 6V as the current will get high (and so the voltage will sag) with the usual parallel connections....but again it depends on the igniters.

I have mentioned that the Estes Sonic igniters, which were made for the Estes-relabeled Aerotech motors that were sold when the Pro Series II was new a decade ago were, I am told by a reliable source, made specifically to fire those motors from a 9V source as the simple and durable PSII launch controller is configured for 6 C-cells. On 12V they fired so quickly that they often didn't get the White Lightning motors lit.

There are too many variables to simply say "6V is good enough" or "12V is too much" for a general case. Personally, almost everything I use regularly uses a 3s LiPoly battery of some sort. I have one in my "just grab it to go flying" PSII controller and both the three-pad system I built for school groups and our club's 5-10 pad system are powered these days from 3s LiPoly packs. The club system, when it came into my possession, was using a Group U1 12V lead acid garden tractor battery. A 5AH 3s LiPoly is MUCH more portable.....

I think if I were starting from scratch I'd look at LiFePo packs, but I have lots of chargers for LiPolys as rockets displaced my electric RC airplanes in my life about the time lithium batteries went mainstream.

Another club I fly with uses 12V jump-starter packs to power all their GSE.
and those jump packs are SLA batteries and several have been replaced if not most in 13 years.
 
On 12V they fired so quickly that they often didn't get the White Lightning motors lit.
I think this is exactly what is happening. What's the right solution for midpower composite? What is a better ignitor solution for D-G Quest/aerotech composite motors?
 
@BEC : On 12V they fired so quickly that they often didn't get the White Lightning motors lit.
I think this is exactly what is happening. What's the right solution for midpower composite? What is a better ignitor solution for D-G Quest/aerotech composite motors?

If that is the case, then they are useless for club launches. Every club I have flown with that has their own launch setup all use 12 volts.

If Quest makes an Ignitor that doesn't work on them, that is a huge problem. I will find out when I can make my next club launch nearby this year on some D22 and E35s. I don't have enough to test in my yard as a static test.

Edit: even my personal launch power is 12volts.
 
@BEC : On 12V they fired so quickly that they often didn't get the White Lightning motors lit.


If that is the case, then they are useless for club launches. Every club I have flown with that has their own launch setup all use 12 volts.

If Quest makes an Ignitor that doesn't work on them, that is a huge problem. I will find out when I can make my next club launch nearby this year on some D22 and E35s. I don't have enough to test in my yard as a static test.

Edit: even my personal launch power is 12volts.
Years back I did a bunch of mass launch pads for a kids launch (takes a lot of impulse to launch a kid but that is another story), I found that the quest igniters were so quick that they would launch before any of the other igniters, plus there was a pretty good chance at least one of the clips falling would short out keeping the remainder from launching. The solution was to put a 1 ohm 'power resistor' in series with each of the pad leads. Worked really well.

This was using a 12V 7.2Ah Lead Acid battery.

YMMV
 
Back
Top