Laser: Home vs Professional?

[awilliams1701]

It was a deal on groupon. From what my sister tells me, it was an OK deal, but not a great deal. She's in California. I'm in Alabama. I got to believe if you check you might find something.

$300??? OMG. Where is THAT? I'm doing laser right now and it's costing me $2000 USD for 6 sessions. Just the facial hair.

[Kova V]

Danger!
Laser Radiation
*                   



pew pew!

*edit*
Oh yeah, this is the laser at the place that zaps me

[awilliams1701]

That looks a lot newer than the one they used on me. The display was made of large blue dots. I suspect it doesn't really matter if it works.

[phdinfunk]

Just going to say, I appreciate this thread and I read the whole thing.

I manage engineers, and I know a bit about electronics.  I think a couple of things need to be said about those cells in the laser hair removal device.

Those are Li-Ion cells, and pretty big ones at that.  To the woman who replaced the cells and it didn't work, I honestly don't know what the issue is.  It's microcontroller-based, so maybe it needs a reset after the batteries have been changed or any number of things.  But the cells themselves should be able to be replaced with 26650s or even 18650s.  Good new panasonic 18650s still don't have as much capacity as the 26650s, but might be easier to find.  All those cells are 3.3v.  The difference is how many milliamp hours of charge they hold in them, which should not affect the circuit other than how long it stays charged.  If they're in parallel, as everyone else pointed out, the Volts are the same, the amps are added.

Also, though, the voltage is going to differ when the cells are fully charged.  This is just a byproduct of how these things work, the voltage isn't perfect, but decreases on a curve as you drain the battery.  Now, that system has a method of overvoltage protection inside of it, because otherwise those cells can actually blow up (you cannot put cells like that in the checked baggage on an airplane, and you cannot ship them via airmail).  It's the same kind of battery that's inside your computer, also with loads of protections on it.  So, the system inside is looking for a max and min voltage to operate in.

She said that the voltage read higher on her replacement cells (sorry, I forgot and it's a few pages back on the thread) and the unit did not work properly.  So, one possibility is that the overvoltage protection on the system is getting tripped somehow.

Anyways, if I were going to replace those cells, I would probably use protected cells, and try to put them in pre-drained if possible and let the machine charge them up all the way.  Of course, you could run it direct off a DC source, maybe at 3v, since that would surely fall into the range that the machine wants to "see."

I hope that helps anybody else out there who is trying to save 500 bucks on a new machine.  You can PM me if you wish, though I very seldom log on here and it could be a year before I respond.

--L

[LadyDrifterLana]

Just going to say, I appreciate this thread and I read the whole thing.

I manage engineers, and I know a bit about electronics.  I think a couple of things need to be said about those cells in the laser hair removal device.

Those are Li-Ion cells, and pretty big ones at that.  To the woman who replaced the cells and it didn't work, I honestly don't know what the issue is.  It's microcontroller-based, so maybe it needs a reset after the batteries have been changed or any number of things.  But the cells themselves should be able to be replaced with 26650s or even 18650s.  Good new panasonic 18650s still don't have as much capacity as the 26650s, but might be easier to find.  All those cells are 3.3v.  The difference is how many milliamp hours of charge they hold in them, which should not affect the circuit other than how long it stays charged.  If they're in parallel, as everyone else pointed out, the Volts are the same, the amps are added.

Also, though, the voltage is going to differ when the cells are fully charged.  This is just a byproduct of how these things work, the voltage isn't perfect, but decreases on a curve as you drain the battery.  Now, that system has a method of overvoltage protection inside of it, because otherwise those cells can actually blow up (you cannot put cells like that in the checked baggage on an airplane, and you cannot ship them via airmail).  It's the same kind of battery that's inside your computer, also with loads of protections on it.  So, the system inside is looking for a max and min voltage to operate in.

She said that the voltage read higher on her replacement cells (sorry, I forgot and it's a few pages back on the thread) and the unit did not work properly.  So, one possibility is that the overvoltage protection on the system is getting tripped somehow.

Anyways, if I were going to replace those cells, I would probably use protected cells, and try to put them in pre-drained if possible and let the machine charge them up all the way.  Of course, you could run it direct off a DC source, maybe at 3v, since that would surely fall into the range that the machine wants to "see."

I hope that helps anybody else out there who is trying to save 500 bucks on a new machine.  You can PM me if you wish, though I very seldom log on here and it could be a year before I respond.

--L

I definitely think you may be on to something, phdinfunk. I'm a hobbyist/geek with lots of experience soldering, repairing, modifying, and troubleshooting basic digital electronics, so maybe I can be of help as well...

As phdinfunk said, it's likely the TRIA's circuitry will have an over-voltage protection system. It may even be set purposefully conservative at ~3.7-4.0V. Li-Ion have the potential for danger, but just as often manufacturers put voltage limits to keep the sensitive li-ion cells from being "stressed" too hard in either direction. Stress can shorten the usable life of the battery/it's storage capacity. Overcharging or deep-discharging a li-ion is very very bad for it's performance! They are extremely sensitive as far as battery tech goes, so manufacturers of end products (e.g. Apple, Samsung) keep a tight grip on their battery charge tolerances lest they come to be known as wildly unreliable.

The batteries might have been "topped up" right before shipping and are now at something just slightly out of normal spec like 4.35V. Sellers online do a lot of strange things. I hear that a lot of the 18650s and similar batteries out there are fakes, with unrealistic capacity ratings.

Bottom line - Voltage of the new battery "pack" needs to be measured. I would also carefully inspect the wiring of the other pack. Perhaps there's a resistor or something that we're missing...

I believe nominal is ~ 3.7 volts. Range of 3.3 to 4.2 and typically 4.2 is fully charged.

Perhaps a call should be made to TRIA support to ask what the lights mean. Maybe ask before mentioning the battery modification... 

Also - What happens with the old battery installed?

As far as connecting the device to the wall - I suspect the amperage draw of the TRIA during the light pulse may be too high to reliably power it with any common 3.6V ~1000ma DC power adapter. Those li-ion cells can supply a much higher current for a split-second than any small DC adapter. I mean, look at the size of those wires attached to the batteries. I'm not sure what other circuitry the TRIA uses but I see there is a heat sink AND a fan inside the machine which takes up quite a bit of room. That implies a lot of energy dissipation which means power  .

If the batteries are 4400 mah and it can discharge a lot of that into heat and IPL very quickly, I suspect the amperage draw during those short bursts will be pretty high. Perhaps somebody with more information on how quickly you can "use up" the TRIA's battery during a session can do the math to find the average current draw. However, it still tells us very little about the sharp increases in load that the power source may see over a brief interval.

I'd stick to the battery replacement, it seems pretty straightforward once the details get ironed out. We'll reverse engineer this thing yet

[Laura_7]

For those who are looking into less reverse engineering, there are basically at least two systems which are said to have permanent results.

One is the tria and the other is the silk flash n go. (from silk only this one according to descriptions)

The silk flash n go are mains powered and have changeable cartridges, some with a high number of flashes.
If its only for a small area fewer flashes should do.
They are available used. All at your own risk ... look at what you buy and from whom.
There are people who aquired nice devices for less than 100 usd.


*hugs*

[Louisa]

I definitely think you may be on to something, phdinfunk. I'm a hobbyist/geek with lots of experience soldering, repairing, modifying, and troubleshooting basic digital electronics, so maybe I can be of help as well...

As phdinfunk said, it's likely the TRIA's circuitry will have an over-voltage protection system. It may even be set purposefully conservative at ~3.7-4.0V. Li-Ion have the potential for danger, but just as often manufacturers put voltage limits to keep the sensitive li-ion cells from being "stressed" too hard in either direction. Stress can shorten the usable life of the battery/it's storage capacity. Overcharging or deep-discharging a li-ion is very very bad for it's performance! They are extremely sensitive as far as battery tech goes, so manufacturers of end products (e.g. Apple, Samsung) keep a tight grip on their battery charge tolerances lest they come to be known as wildly unreliable.

The batteries might have been "topped up" right before shipping and are now at something just slightly out of normal spec like 4.35V. Sellers online do a lot of strange things. I hear that a lot of the 18650s and similar batteries out there are fakes, with unrealistic capacity ratings.

Bottom line - Voltage of the new battery "pack" needs to be measured. I would also carefully inspect the wiring of the other pack. Perhaps there's a resistor or something that we're missing...

I believe nominal is ~ 3.7 volts. Range of 3.3 to 4.2 and typically 4.2 is fully charged.

Perhaps a call should be made to TRIA support to ask what the lights mean. Maybe ask before mentioning the battery modification... 

Also - What happens with the old battery installed?

As far as connecting the device to the wall - I suspect the amperage draw of the TRIA during the light pulse may be too high to reliably power it with any common 3.6V ~1000ma DC power adapter. Those li-ion cells can supply a much higher current for a split-second than any small DC adapter. I mean, look at the size of those wires attached to the batteries. I'm not sure what other circuitry the TRIA uses but I see there is a heat sink AND a fan inside the machine which takes up quite a bit of room. That implies a lot of energy dissipation which means power  .

If the batteries are 4400 mah and it can discharge a lot of that into heat and IPL very quickly, I suspect the amperage draw during those short bursts will be pretty high. Perhaps somebody with more information on how quickly you can "use up" the TRIA's battery during a session can do the math to find the average current draw. However, it still tells us very little about the sharp increases in load that the power source may see over a brief interval.

I'd stick to the battery replacement, it seems pretty straightforward once the details get ironed out. We'll reverse engineer this thing yet

Hi LadyDrifterLana, I've owned about four tria device of different sorts, two of them 4Xs. One of the 4Xs went unserviceable (all the more so after I'd taken it apart and accidentally damaged the very flimsy/fragile ribbon cables!). However, from this experience and gaining some familiarity with the 4X's innards, I reckon most trias blow, for the same reason I speculate mine did - and that is using them on setting 4 or 5 straight after turning them on - because of this placing far too great a load on a 'cold' battery.

As was noted above, the wires from the battery are huge, and this struck me as soon as I saw inside the unit. I wouldn't be surprised if they have a capacity of 30, 40 or 50 amps. This made me suspect that what had happened to the unit which blew (especially given it was in perfect condition with only a few hours use on it) was that using it straight off on 4 and 5 had just pulled too much out of the battery (when it was cold) and had thus caused it to malfunction inside.

This also ties in with how the unit would seem like it was charging fine, but then seemingly have no power in it.

So the 'moral' of this experience, I believe, is to let a tria warm up for a few minutes, by starting it out on 2, then move to 3 for a while and then when fully warmed up, only then move to 4 or 5. I think it's no so much the warming up of the electronics and the laser unit which is important, but rather the warming up of the battery - so that it is better placed to have a very large current draw placed on it.