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#1 Droid31

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Posted 07 December 2014 - 12:03 PM

Hello I recently did full motor replacement and rewire on a rapidstrike. I was looking at IMR and Trustfire batteries, but have seen some videos and vape forms on batteries exploding and failing. Has anyone on here had any batteries fail?
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#2 Lunas

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Posted 07 December 2014 - 05:38 PM

Hello I recently did full motor replacement and rewire on a rapidstrike. I was looking at IMR and Trustfire batteries, but have seen some videos and vape forms on batteries exploding and failing. Has anyone on here had any batteries fail?

i have seen videos on li-ion trust/sure/ultra fires 18650 laptop cells venting i have also seen videos of li-po turnigy packs venting after swelling like a balloon and i have personally seen a samsung phone battery swell up 3 times the size it is supposed to be.


I have never found an IMR video on them venting only them getting purposely shorted getting to almost 200F fusing the wire then dropping to 0v

Efest makes a 26650 IMR cell with high discharge up to 30A that would fit in the stock rapidstrike tray with a little modding.
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#3 PandaSPUR

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Posted 07 December 2014 - 08:59 PM

I've been researching a bit about batteries for the RS this past weekend since I just ordered a new RS from Target.

Anyway, from the information I've found, Trustfire or other Li-Ion 14500, 18650, 26650 cells are not good for our blasters because they dont have enough current output capability.

IMRs are better as they do provide enough current, as Lunas suggested. It seems like Efest Purple cells are the most popular. Efest 26650 IMR cells would fit in the stock battery tray since the cells are the same diameter as C-size Alkalines, but they're 15mm longer. From my personal searching, I though the GREEN Efest 26650 IMRs would be best since they provide less current than the Purples but have more capacity and the current is still enough for Nerf uses.

However, I've also had a few people convince me to go with the RC battery pack route and directly wire the battery rather than use the stock or any battery holder as those have inherently high resistance.

I had a lot of advice from others on the Nerf sub-reddit: http://www.reddit.co...in_rapidstrike/

Edited by PandaSPUR, 07 December 2014 - 09:17 PM.

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#4 Lunas

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Posted 07 December 2014 - 10:59 PM

I've been researching a bit about batteries for the RS this past weekend since I just ordered a new RS from Target.

Anyway, from the information I've found, Trustfire or other Li-Ion 14500, 18650, 26650 cells are not good for our blasters because they dont have enough current output capability.

IMRs are better as they do provide enough current, as Lunas suggested. It seems like Efest Purple cells are the most popular. Efest 26650 IMR cells would fit in the stock battery tray since the cells are the same diameter as C-size Alkalines, but they're 15mm longer. From my personal searching, I though the GREEN Efest 26650 IMRs would be best since they provide less current than the Purples but have more capacity and the current is still enough for Nerf uses.

However, I've also had a few people convince me to go with the RC battery pack route and directly wire the battery rather than use the stock or any battery holder as those have inherently high resistance.

I had a lot of advice from others on the Nerf sub-reddit: http://www.reddit.co...in_rapidstrike/

I have a Rapidstrike i upgraded the battery tray with a pair of 18650s in series for 8.4-7.4v the stock wiring is fine for the stock motors and stock contacts if you motor swap you will want to run wires to the end of the springs or to another method of connecting the tray or direct wire to a pack the stock springs and contacts should be good up to about 10A if you are running motors that can pull more than that perhaps epoxying a connector to the inside and then to the battery tray would be a good idea.
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#5 PandaSPUR

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Posted 07 December 2014 - 11:36 PM

I have a Rapidstrike i upgraded the battery tray with a pair of 18650s in series for 8.4-7.4v the stock wiring is fine for the stock motors and stock contacts if you motor swap you will want to run wires to the end of the springs or to another method of connecting the tray or direct wire to a pack the stock springs and contacts should be good up to about 10A if you are running motors that can pull more than that perhaps epoxying a connector to the inside and then to the battery tray would be a good idea.


Question, how much of a performance difference do you notice with 18650s while keeping everything else stock?

I've been conflicted as to how I want to modify my own RS.

RC Pack + Charger = $40 after shipping from Hobbyking
2x18650 = $15-ish + another $15-25 for a charger (like a Nitecore D2/D4)
2x26650 = $22 for battery + charger ^

It seems like with stock wiring/internals, the RC pack wouldn't provide and extra performance over the IMR solutions. But for a slightly higher "price of entry", the RC pack route has more leftover potential for future upgrades.
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#6 Lunas

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Posted 08 December 2014 - 12:54 AM

Question, how much of a performance difference do you notice with 18650s while keeping everything else stock?

I've been conflicted as to how I want to modify my own RS.

RC Pack + Charger = $40 after shipping from Hobbyking
2x18650 = $15-ish + another $15-25 for a charger (like a Nitecore D2/D4)
2x26650 = $22 for battery + charger ^

It seems like with stock wiring/internals, the RC pack wouldn't provide and extra performance over the IMR solutions. But for a slightly higher "price of entry", the RC pack route has more leftover potential for future upgrades.

night and day vs c batteries the darts fly 50-80Ft i can empty the full clip in about 3-4 seconds and it spins up rather quick.

I bought a nitecore d4 and my batteries. I really like the d4. And i have flashlights and usb chargers that use 18650 cells.
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#7 jwasko

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Posted 08 December 2014 - 12:21 PM

i have seen videos on li-ion trust/sure/ultra fires 18650 laptop cells venting i have also seen videos of li-po turnigy packs venting after swelling like a balloon and i have personally seen a samsung phone battery swell up 3 times the size it is supposed to be.

It should be noted that any Lithium Polymer battery can be extremely dangerous if used incorrectly. Shorting a LiPo RC pack will probably cause a fire that could burn your entire house down, just like shorting a ____fire (or using a knockoff of poor quality) will probably make it blow up in your face.

IMR cells (LiMn, I believe) and LiFe battery packs (like this) are still dangerous, but are generally a bit more stable (i.e., probably won't blow up in your face/burn your house down but still be careful!). NiMH cells are also stable, although they are usually pretty large compared to the blaster you are trying to hook them up to.

Note: If you get an LiFe pack, I'm fairly certain you cannot use one of those cheap LiPo chargers on HobbyKing. You need something like an IMax B6 that can do both LiPo and LiFe.

Edited by jwasko, 08 December 2014 - 12:21 PM.

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#8 Spiderbite

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Posted 08 December 2014 - 04:06 PM

Everyone bashes against trustfire/ultrafire batteries. What's the problem? They make a normal flywheel blaster shoot substantially harder, with little/no modification to the circuit, motors, or shell.
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Or hell, Spiderbite has sweet deals on this stuff now, so there's really no reason not to Rainbow.

[k26] springs!

#9 Lunas

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Posted 08 December 2014 - 04:19 PM

Everyone bashes against trustfire/ultrafire batteries. What's the problem? They make a normal flywheel blaster shoot substantially harder, with little/no modification to the circuit, motors, or shell.

The issues occur due to multi cell use with the uneven discharge this causes hot cells that can vent fire hot hydrofluric acid possibly into your face. Li-mn and li-fe just get hot then stop working. Lipo batteries can on a whim swell to 3 times the correct size and vent hydrogen typically on fire so you have a torch burning hot enough to melt steel followed by a lithium fire you can't just put out with water or most fire extinguishers.

But that's fine if you want to melt your face off you may.

then there is the fake fires sold on amazon and eBay which can be old cells forced to take a charge literally ticking time bombs can go off left in a drawer with nothing to short it. or small 30mAh cells stuffed into the can with flour or plaster to make the weight right. So it charges shows voltage but only has 30mAh instead of 3000mAh.

you will see lots of issues showing up in relation to vaping but realize vaping is shorting high resistance wire to produce heat so intentional shorting of a dangerous cell... If they used control boards to prevent a short on the battery they would not have mods becoming rocket propelled cylinders.

Edited by Lunas, 08 December 2014 - 04:42 PM.

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#10 jwasko

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Posted 08 December 2014 - 04:40 PM

Just to calrify, to all those that want to "make a normal flywheel blaster shoot substantially harder, with little/no modification to the circuit, motors, or shell."

IMR cells are just like trustfires: they fit in your AA battery tray, will work with stock motors and wiring if you want (you may or may not have to short out the thermistor) and even charge in a trustfire charger.

They also have the added benefits of:
1. Being safer (see Lunas' post)
2. Putting out more current (letting you your motors spin up faster and letting you react to a surprise attacker/zombie/etc faster)
3. Having more capacity (they last longer per charge)

All for an extra $10 per pair of cells (if that, I think).

Edited by jwasko, 08 December 2014 - 04:41 PM.

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#11 Droid31

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Posted 08 December 2014 - 08:23 PM

Just to calrify, to all those that want to "make a normal flywheel blaster shoot substantially harder, with little/no modification to the circuit, motors, or shell."

IMR cells are just like trustfires: they fit in your AA battery tray, will work with stock motors and wiring if you want (you may or may not have to short out the thermistor) and even charge in a trustfire charger.

They also have the added benefits of:
1. Being safer (see Lunas' post)
2. Putting out more current (letting you your motors spin up faster and letting you react to a surprise attacker/zombie/etc faster)
3. Having more capacity (they last longer per charge)

All for an extra $10 per pair of cells (if that, I think).

So would NiMH packs work ok and be safe?
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#12 snakerbot

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Posted 08 December 2014 - 08:48 PM

Nickel packs are very stable, and if you get a good RC pack it will work very well for you. Just be sure to get the right voltage. Nickel packs are 1.2V per cell, versus 3.7V per lithium cell, so you need more of them for the same voltage. Exactly how many cells to use will depend on what motors you bought.

Note that jwasko mostly talked about Lithium Ion Manganese batteries (IMRs), not Nickel based NiMH (Nickel Metal Hydride) and NiCd (Nickel Cadmium). Either one will probably work for you. IMR drop-ins are an option, and will be better than NiMH drop-ins or -fires, but a good RC-grade NiMH pack will be better than any drop-in option.
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#13 Droid31

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Posted 08 December 2014 - 10:15 PM

Nickel packs are very stable, and if you get a good RC pack it will work very well for you. Just be sure to get the right voltage. Nickel packs are 1.2V per cell, versus 3.7V per lithium cell, so you need more of them for the same voltage. Exactly how many cells to use will depend on what motors you bought.

Note that jwasko mostly talked about Lithium Ion Manganese batteries (IMRs), not Nickel based NiMH (Nickel Metal Hydride) and NiCd (Nickel Cadmium). Either one will probably work for you. IMR drop-ins are an option, and will be better than NiMH drop-ins or -fires, but a good RC-grade NiMH pack will be better than any drop-in option.

Yea I'm not worried about easy install or anything, all I am worried about is the damn thing not venting or exploding or catching on fire or some stupid shit. I was thinking of going with a 7.2 volt pack, and the motors will take it no problem.
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#14 PandaSPUR

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Posted 08 December 2014 - 10:42 PM

Err to be clear though, I wouldn't consider IMRs to be a drop-in for the RS unless you want to use the low capacity 14500 cells with AA to C spacer/converters.

The 18650 and 26650 cells are both longer than the standard C cell alkaline battery. So you would need to do at least a tiny bit of modification to get them to fit.

Anyway, I don't own the RS (yet) so I have no actual experience doing any of this. Just repeating info that I found myself.

If you end up with a 7.2 pack, this was my plan for if I went that route:
7.2v 2200mAH Li-Po Battery Pack: http://www.hobbyking...idProduct=16203
Entry-level Charger: http://www.hobbyking...duct=63446.html
Connectors that you'll need to wire up/solder on the gun: http://www.hobbyking...duct=52411.html

Runs about $40 after shipping for me. Same price as getting something like 2x 18650 and a Nitecore D4 charger.
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#15 snakerbot

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Posted 08 December 2014 - 11:18 PM

Yea I'm not worried about easy install or anything, all I am worried about is the damn thing not venting or exploding or catching on fire or some stupid shit. I was thinking of going with a 7.2 volt pack, and the motors will take it no problem.

Realistically, lithiums are fine. You hear the horror stories and they stick, but treat any battery properly and it'll work fine in all likelihood. That said, nickel is closer to idiot-proof than lithium.

Err to be clear though, I wouldn't consider IMRs to be a drop-in for the RS unless you want to use the low capacity 14500 cells with AA to C spacer/converters.

The 18650 and 26650 cells are both longer than the standard C cell alkaline battery. So you would need to do at least a tiny bit of modification to get them to fit.

Whoops. You are correct. My bad.
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#16 PandaSPUR

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Posted 09 December 2014 - 02:00 AM

Realistically, lithiums are fine. You hear the horror stories and they stick, but treat any battery properly and it'll work fine in all likelihood. That said, nickel is closer to idiot-proof than lithium.


This. "Traditional" lithium batteries, i.e. not IMR, have been used for a long time in all sorts of electronics with varying levels of protections, failures are pretty rare.
As long as you stick with something that is purpose made for the task, and is of high quality, you'll be fine.

Quality RC packs for example, are built for high discharge applications and the cells within the pack were properly matched. Those wont give you issues.

Trustfire and similar Lithium cells are bad and labeled as dangerous by some since they're not meant for high discharge at all. So when you demand a lot from those batteries, they get hot quick and thats when things can get dangerous.

Whoops. You are correct. My bad.


^_^ its all good.
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#17 CS- Tiff

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Posted 09 December 2014 - 04:47 PM

Well NiMH is pretty safe. The only downside to it is the output per cell. (1.2v)
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#18 Droid31

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Posted 09 December 2014 - 08:41 PM

Well NiMH is pretty safe. The only downside to it is the output per cell. (1.2v)


So would something like this Link work?
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#19 Love777

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Posted 09 December 2014 - 10:27 PM

So would something like this Link work?



Yeah those are fine but these are usually cheaper and include the charger: Here
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#20 snakerbot

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Posted 09 December 2014 - 10:58 PM

So would something like this Link work?

Yeah those are fine but these are usually cheaper and include the charger: Here

Those two batteries are not interchangeable. 7.2V versus 9.6V should tip you off right away. Also, the True Energy 9.6V pack has less than half the capacity, but this is less potentially damaging than overvolting your motors too much. Which you should use ultimately depends on what motors you used and what kind of performance you want out of them. If you used the Mabuchi FK180sh that everyone calls "Blade 180s", then neither will likely damage the motors, the 9.6V will shoot harder, and the 7.2V will last longer.
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#21 Droid31

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Posted 10 December 2014 - 12:09 AM

Those two batteries are not interchangeable. 7.2V versus 9.6V should tip you off right away. Also, the True Energy 9.6V pack has less than half the capacity, but this is less potentially damaging than overvolting your motors too much. Which you should use ultimately depends on what motors you used and what kind of performance you want out of them. If you used the Mabuchi FK180sh that everyone calls "Blade 180s", then neither will likely damage the motors, the 9.6V will shoot harder, and the 7.2V will last longer.


Yea I used the blades, I want a high amp hour one like the one I posted. And I also want the 7.4 volts, but I do not want that pack I posted because it has some bad reviews.
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#22 PandaSPUR

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Posted 10 December 2014 - 01:04 AM

Yea I used the blades, I want a high amp hour one like the one I posted. And I also want the 7.4 volts, but I do not want that pack I posted because it has some bad reviews.


http://hobbyking.com...Stick_Pack.html

That should be better. Turnigy is a good brand from my googling research.
Only issue is that this site only has it at their international warehouse, so shipping would take a while.
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#23 Lunas

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Posted 11 December 2014 - 06:55 PM

Err to be clear though, I wouldn't consider IMRs to be a drop-in for the RS unless you want to use the low capacity 14500 cells with AA to C spacer/converters.

The 18650 and 26650 cells are both longer than the standard C cell alkaline battery. So you would need to do at least a tiny bit of modification to get them to fit.


They are longer than a single c by about 1 inch not enough to take the place of 2 c inline.

I bought a 18650 2s1p protected battery tray and used 2 sided tape to stick it in the battery tray i used a rotary tool to remove the center divider and drilled out a hole to enlarge the area where the contacts sit and i soldered the wires directly to the contacts

Thinking back to how i modded it one could probably solder 16 awg to the plate and run it through the holes into the tray. Or you could sit both halfs of an xt60 connector on the one side of the shell with one in the battery tray would preserve the function of the tray while allowing the use of 30-60A IMR 26650 (MORE THAN ENOUGH AMPS).
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#24 PandaSPUR

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Posted 12 December 2014 - 01:16 AM

They are longer than a single c by about 1 inch not enough to take the place of 2 c inline.

I bought a 18650 2s1p protected battery tray and used 2 sided tape to stick it in the battery tray i used a rotary tool to remove the center divider and drilled out a hole to enlarge the area where the contacts sit and i soldered the wires directly to the contacts

Thinking back to how i modded it one could probably solder 16 awg to the plate and run it through the holes into the tray. Or you could sit both halfs of an xt60 connector on the one side of the shell with one in the battery tray would preserve the function of the tray while allowing the use of 30-60A IMR 26650 (MORE THAN ENOUGH AMPS).


Yep, so it requires some modification to fit :P

My plan is basically the same as yours. I decided to go with 18650s since the Nitecore D4 charger is really nice and works with all of my other rechargeable batteries.
Bought a cheapo $3 dual 18650 battery holder, will stick that in the stock battery tray and solder it to the contacts at the back of the tray.

Cheapo $3 holder will have to eventually be replaced if I rewire the entire thing, but with a stock RS its not any weaker than the other wiring in the gun anyway.

Another option would be to use 26650s with custom sized dummy cells and just remove the dividing plastic piece on each side. No soldering even required with this, but then I couldn't find custom sized dummy cells.

Edited by PandaSPUR, 12 December 2014 - 01:17 AM.

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#25 Lunas

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Posted 12 December 2014 - 12:48 PM

It is not even dummy cells since you need 2 you need a spacer at one end just under an inch thick with a thick wire connecting the 2 cells

That said a 18650 is more easily available and useful in more ways I have 12 18650 I got from laptop batteries 4 from flashlights and 2 imr for my rs

This. "Traditional" lithium batteries, i.e. not IMR, have been used for a long time in all sorts of electronics with varying levels of protections, failures are pretty rare.
As long as you stick with something that is purpose made for the task, and is of high quality, you'll be fine.

Quality RC packs for example, are built for high discharge applications and the cells within the pack were properly matched. Those wont give you issues.

Trustfire and similar Lithium cells are bad and labeled as dangerous by some since they're not meant for high discharge at all. So when you demand a lot from those batteries, they get hot quick and thats when things can get dangerous.



^_^ its all good.

Yep nothing wrong with lithium cells as long as you don't abuse them. Non IMR typically only have issues with the following; multiple cells not equally charged in series, cells that have been fully killed then recharged, cells that are overcharged, cells with physical damage, or shorting the neg to positive terminals. With a quality charger like the nitecore i2/4 d2/4 or imax b6. It would be fine to use them.

But that said nerf is a sport jarring and dropping blasters are common.

Edited by Lunas, 12 December 2014 - 08:31 PM.

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