Zebralights new battery tube design(SC600 MKII, SC63, SC5, exc.)

There has been a lot of controversy surrounding Zebralights new end cap and battery tube design. For those of you that dont know, ZL has changed the design of their battery compartment and end cap on some of their new models. This change includes a shorter battery compartment which limits the accepted battery size to exactly 65mm vs. anywhere from 65mm or less to 69mm with the old design. The positive and negative battery contact points have been changed from a traditional duel spring design as well. The positive contact changes from a spring to a flexible tab and the negative contact(on the tail cap) changes to what ZL dimes a "pogo pin" design from a large spring. Pogo pins are basically a number of tiny tubular spring loaded pistons that make contact with the negative end of the battery instead of a spring.

This design change has many pros and cons including:

Pros:

1. Lower overall length(4mm shorter)
2. Lower overall weight
3. Easier to screw on tail cap(due to shorter throw on the contact points and less contact pressure)
4. Possibly more contact surface area on bare cells(due to many pins contacting the negative terminal vs. one spring coil)

Cons:

1. No protected battery support due to shorter length
2. Less overall battery compatibility(cell has to be exactly 65mm in length)
3. Less shock resistance due to less "spring cushion" between the battery and tube ends/circuitry(weapon mountable lights use a duel spring design for this reason)
4. Less contact pressure(which increases chance of connection issues and battery rattle/vibration)
5. Less safety margin(due to the inability to use protected cells for redundant over discharge/over charge protection)
6. Unproven design(long term durability/reliability of tiny springs in pogo pins is unknown)

So, do you like this new design and feel it is worth the trade offs?

Wait, do we know that those cons are real? I know a lot of those claims have been made, but have they been proven? The only light I have with this new design is my SC5w so my data set is small, but I've never had a problem with shock resistance (3, 4), dropping connectivity (4) or rattling (4). 1 and 5 are basically the same thing and it has not been shown to be an issue either. I can't recall one person who's had an unprotected cell fail in a light because the built-in circuitry failed, so at best those claims are fear-mongering and speculation. As is 6, for that matter.

So as I see it, the only real negative to the new design is #2.

I've had the SC5 for close to a year now with no issues at all. It's been dropped several times with no issues, battery fits perfectly and works well with no contact issues or battery rattle. It's a welcome change for the Zebralight and I'm glad to see it. They also said the initial batch of MK3 did have the battery rattle issue but it has been fixed now so shouldn't be anymore issues with that. When done correctly the battery actually can't move up and down due to the pogo pins having limited movement as well. It gives just enough to screw the battery on tightly and no more, this prevents the battery from suddenly moving inside the tube in any direction when dropped since there is no travel when fully tightened. Imo it's a superior design and I am glad they're going this direction.

Protected batteries can can be just as dangerous as bare cells because many assume that since they're "safe" they don't need to practice good charging techniques or worry about discharging it too much. Also I've had a protected cell where the wrapper was damaged and the thin metal wire down the side was exposed. If I didn't practice good safety with 18650 batteries I could have easily put it in my light and caused major issues. When good charging practices are used and a light like the ZL which dims when the battery is low and shuts off if any concerns or too low voltage I think unprotected are just as safe as protected cells. Therefore it's a good move for ZL.

I also agree the cons need to be edited some. The pogo pins have been in use on the SC5 for nearly a year with no issues that I've seen anywhere. No contact issues, reliability problems, issues, when dropped, etc. As I said above ZL had an issue with the initial MK3 batch with battery rattle but that was a manufacturing problem and has since been corrected. When done correctly pogo pins are just as good if not better imo based on my experience with the SC5.

snowlover91 said:

I've had the SC5 for close to a year now with no issues at all. It's been dropped several times with no issues, battery fits perfectly and works well with no contact issues or battery rattle. It's a welcome change for the Zebralight and I'm glad to see it. They also said the initial batch of MK3 did have the battery rattle issue but it has been fixed now so shouldn't be anymore issues with that. When done correctly the battery actually can't move up and down due to the pogo pins having limited movement as well. It gives just enough to screw the battery on tightly and no more, this prevents the battery from suddenly moving inside the tube in any direction when dropped since there is no travel when fully tightened. Imo it's a superior design and I am glad they're going this direction.

Protected batteries can can be just as dangerous as bare cells because many assume that since they're "safe" they don't need to practice good charging techniques or worry about discharging it too much. Also I've had a protected cell where the wrapper was damaged and the thin metal wire down the side was exposed. If I didn't practice good safety with 18650 batteries I could have easily put it in my light and caused major issues. When good charging practices are used and a light like the ZL which dims when the battery is low and shuts off if any concerns or too low voltage I think unprotected are just as safe as protected cells. Therefore it's a good move for ZL.

Click to expand...

no travel means no shock absorption to protect the cell right? Maybe AAs are not as susceptible, but scaling up to 18650s might be a different matter: I have an 18650 with a dented flat top from a drop, while in a non-ZL light though.

Unless ZL replaces all purchased lights with the rattling for free, including return shipping, I'd hate to be another one who buys from that initial batch.

scs said:

no travel means no shock absorption to protect the cell right? Maybe AAs are not as susceptible, but scaling up to 18650s might be a different matter: I have an 18650 with a dented flat top from a drop, while in a non-ZL light though.

Click to expand...

Usually with a light that has just a tailcap sring on one end but nothing at the head what happens is when dropped the spring compresses some and the force of the battery goes towards the head as the momentum shifts. The tail spring absorbs the initial "recoil" fine but then as the battery moves forward it slams into the circuit board and causes issues. This is typically solved by a second spring in the head. However when done correctly the pogo pins don't allow the battery to move in any direction, there is no give, so the battery won't "slam" into the circuit board because it can't move its wedged in place by the pins. This has been my experience with the SC5 and I believe it would likewise have similar results with the 18650.

scs said:

Unless ZL replaces all purchased lights with the rattling for free, including return shipping, I'd hate to be another one who buys from that initial batch.

Click to expand...

I'm sure if the user has an issue with it and contacts them within 30 days it would be replaced and they would probably cover shipping charges too. Either way it seems the issue has been corrected for the MK3 and it shouldn't be a problem from here on out.

snowlover91 said:

Usually with a light that has just a tailcap sring on one end but nothing at the head what happens is when dropped the spring compresses some and the force of the battery goes towards the head as the momentum shifts. The tail spring absorbs the initial "recoil" fine but then as the battery moves forward it slams into the circuit board and causes issues. This is typically solved by a second spring in the head. However when done correctly the pogo pins don't allow the battery to move in any direction, there is no give, so the battery won't "slam" into the circuit board because it can't move its wedged in place by the pins. This has been my experience with the SC5 and I believe it would likewise have similar results with the 18650.

Click to expand...

good point. Thanks.

1. No protected battery support due to shorter length

2. Less overall battery compatibility(cell has to be exactly 65mm in length)

3. Less shock resistance due to less "spring cushion" between the battery and tube ends/circuitry(weapon mountable lights use a duel spring design for this reason)

4. Less contact pressure(which increases chance of connection issues and battery rattle/vibration)

5. Less safety margin(due to the inability to use protected cells for redundant over discharge/over charge protection)

6. Unproven design(long term durability/reliability of tiny springs in pogo pins is unknown)

So, do you like this new design and feel it is worth the trade offs?


No it is not worth it imo.

snowlover91 said:

Usually with a light that has just a tailcap sring on one end but nothing at the head what happens is when dropped the spring compresses some and the force of the battery goes towards the head as the momentum shifts. The tail spring absorbs the initial "recoil" fine but then as the battery moves forward it slams into the circuit board and causes issues. This is typically solved by a second spring in the head. However when done correctly the pogo pins don't allow the battery to move in any direction, there is no give, so the battery won't "slam" into the circuit board because it can't move its wedged in place by the pins. This has been my experience with the SC5 and I believe it would likewise have similar results with the 18650.

Click to expand...

All of the energy of the drop is still transferred to the cell though in a rigid design(just like the driver in a car with no suspension). With a duel spring setup, it protects the cell by acting as a shock absorber. Plus, there will always be cell movement as the pogo pin design is not rigid, it just has far less throw.

You guys can pick apart my cons all you want but, they are still cons and valid points(no matter to what degree) vs a traditional duel spring design.

recDNA said:

1. No protected battery support due to shorter length

2. Less overall battery compatibility(cell has to be exactly 65mm in length)

3. Less shock resistance due to less "spring cushion" between the battery and tube ends/circuitry(weapon mountable lights use a duel spring design for this reason)

4. Less contact pressure(which increases chance of connection issues and battery rattle/vibration)

5. Less safety margin(due to the inability to use protected cells for redundant over discharge/over charge protection)

6. Unproven design(long term durability/reliability of tiny springs in pogo pins is unknown)

So, do you like this new design and feel it is worth the trade offs?


No it is not worth it imo.

Click to expand...

Points 3, 4, and 6 are unfounded concerns since the SC5, as stated above, has no issues with these things and is quite reliable and shock resistant. Points 1 and 5 are also speculative and a matter of personal preference. Careful safety measures should be practiced with any 18650 battery and if done by the user make protected cells redundant. You also have the risk of protected cells shorting if the wrapper is exposed, their own circuits could fail, etc so the perceived safety is only applicable in situations where a user is negligent or careless. In fact I would assert that users with protected batteries are more likely to be careless because they have the mindset that the protection makes it safe whereas those who use mainly unprotected cells like myself understand the risks and take precautions that should be applied to both cell types.

Tachead said:

All of the energy of the drop is still transferred to the cell though in a rigid design(just like the driver in a car with no suspension). With a duel spring setup, it protects the cell by acting as a shock absorber. Plus, there will always be cell movement as the pogo pin design is not rigid, it just has far less throw.

You guys can pick apart my cons all you want but, they are still cons and valid points(no matter to what degree) vs a traditional duel spring design.

Click to expand...

I wouldn't consider them a valid concern when no shock issues have been demonstrated in the MK3 or the SC5 which has been around awhile. Also the original contact issues were a manufacturing problem which has since been corrected. I have experience with pogo pins since I own a few of the SC5 lights which use them and they are superior to my other lights using springs.

I'm also fine with my SC5w and don't notice any problems with rattling or drops (granted I haven't dropped my SC5w that much).

The only idea I don't like as much with the new MK3 or SC63 is the strict battery size restriction..but I may eventually end up picking one up anyways.

I'll vote in a couple of months, when I can give it a fair evaluation. I wouldn't have ordered mine if the requirement of non-protected cells bothered me.

I don't mind the battery length restriction. I think some are incorrectly thinking you have to go around shopping and measure the cell with a $200 set of calipers before purchasing. It's not that strict. Any of the common flattop cells will work (Panasonic, Sony, LG, Samsung). At least in my experience. I tried everything I had without any problems. Don't use any kind of button top - protected or unprotected. And give unprotected cells a shot. I bet you won't die or burn your house down.

I didn't like the rattle in the SC600 MK III.

Absolutely NO problems with my SC5w, so if they iron out some kinks in the SC600 I would be happy.

I'm sorry to say it but I won't buy any of the coming lights if they don't fit protected batteries.
But that's just me.

snowlover91 said:

I wouldn't consider them a valid concern when no shock issues have been demonstrated in the MK3 or the SC5 which has been around awhile. Also the original contact issues were a manufacturing problem which has since been corrected. I have experience with pogo pins since I own a few of the SC5 lights which use them and they are superior to my other lights using springs.

Click to expand...

Yeah but, most people baby their lights. Have you dropped your SC5s onto concrete or something else hard from a distance? How many times? How many will it take to cause issues compared to a duel spring design? How do you know no damage was done? Also, the SC5 uses AA's not 18650s which are a lot heavier and more susceptible to damage. As is the light due to the higher impact energy due to weight. There is a reason why pretty much every weapon mountable light uses a duel spring design(shock resistance). How do you know these issues were corrected? Why are they superior in your opinion?

In my opinion, the design is definitely not superior due to the cons I listed and because they far outway the pros. From an engineering standpoint the design is fundamentally weaker. Weaker means inferior to me anyway. Also, springs last decades. They are time tested and proven many times over. Will the positive tab or pogo pins last decades? Who knows.

Why change a design when it is safer, has less liability concerns for the company and its dealers, is more durable by its very design, offers more compatibility(without excluding anyones preferences), and most importantly is time tested for decades to be effective? To save 4mm? To save a couple of grams? I dont know, ask Zebralight. A stupid decision if you ask me.

Tachead said:

Yeah but, most people baby their lights. Have you dropped your SC5s onto concrete or something else hard from a distance? How many times? How many will it take to cause issues compared to a duel spring design? How do you know no damage was done? Also, the SC5 uses AA's not 18650s which are a lot heavier and more susceptible to damage. As is the light due to the higher impact energy due to weight. There is a reason why pretty much every weapon mountable light uses a duel spring design. How do you know these issues were corrected? Why are they superior in your opinion?

In my opinion, the design is definitely not superior for the reasons I listed. From an engineering standpoint the design is fundamentally weaker. Weaker means inferior to me anyway. Also, springs last decades. They are time tested and proven many times over. Will the positive tab or pogo pins last decades? Who knows.

Why change a design when it is safer, has less liability concerns for the company and its dealers, is more durable by its very design, offers more compatibility(without excluding anyones preferences), and most importantly is time tested for decades to be effective? To save 4mm? To save a couple of grams? I dont know, ask Zebralight. A stupid decision if you ask me.

Click to expand...

Mine has been dropped on concrete twice and a hardwood floor once, which is a pretty good test for me and within the limits of my normal usage. I'm not mounting them on guns so dual springs aren't necessary. Electronics are potted and the pogo pins are plenty durable. The design itself is a small circular disk soldered onto a small spring underneath. Do a google search on pogo pins and you'll see they are well regarded and similar to springs but sometimes used for applications that springs don't work well for. From a design standpoint they're no different than using the single spring like the SC62 has.

I emailed ZL and they said there was a problem in the tolerances for the first batch of MK3 lights which has now been fixed. I will take their word for it as I have seen initial problems with new lights or designs that are quickly fixed in subsequent batches. Additionally the change wasn't just to save in size, if you read what ZL posted on another site they said it was for multiple reasons including driver designs requiring it, new LED's requiring higher voltage and amp draw, limitations of protected batteries (amp draw limited by protection circuit, less than 5 amps for most cells with a few rare exceptions). It's not just to save on length, ZL made it clear its many different reasons why they made the switch and the majority of users are fine with it as evidenced by their high demand. I would encourage others to read what they said on Reddit and email them about any concerns they're really good at responding and providing answers.

snowlover91 said:

Mine has been dropped on concrete twice and a hardwood floor once, which is a pretty good test for me and within the limits of my normal usage. I'm not mounting them on guns so dual springs aren't necessary. Electronics are potted and the pogo pins are plenty durable. The design itself is a small circular disk soldered onto a small spring underneath. Do a google search on pogo pins and you'll see they are well regarded and similar to springs but sometimes used for applications that springs don't work well for. From a design standpoint they're no different than using the single spring like the SC62 has.

I emailed ZL and they said there was a problem in the tolerances for the first batch of MK3 lights which has now been fixed. I will take their word for it as I have seen initial problems with new lights or designs that are quickly fixed in subsequent batches. Additionally the change wasn't just to save in size, if you read what ZL posted on another site they said it was for multiple reasons including driver designs requiring it, new LED's requiring higher voltage and amp draw, limitations of protected batteries (amp draw limited by protection circuit, less than 5 amps for most cells with a few rare exceptions). It's not just to save on length, ZL made it clear its many different reasons why they made the switch and the majority of users are fine with it as evidenced by their high demand. I would encourage others to read what they said on Reddit and email them about any concerns they're really good at responding and providing answers.

Click to expand...

My duel spring design ZL has plenty of space around the cell, no rattle. Why, higher contact pressure due to duel spring design. Higher contact pressure = more reliable(less chance of contact issues or cell movement) imo.