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3.5W NDB7A75 445nm Laser Diode

IWIRE

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The Efest work pretty good. I had a lot of voltage drop and battery problems with a build with that diode.
The Imren tested best and worked best, followed by an LG battery I had gotten from Larry, the Efest came in third best followed by a bunch of Panasonic and sanyo batteries.
If the Efest doesn't work out for you try these ,2 PC Imren IMR 18650 Li ion Battery High Drain Rechargeable 3 7V 2600mAh 38A Red | eBay the seller ships really fast. I bought up about 20 of them :) Imren is suppose to be coming out with a 40a battery but I haven't found it available yet. Good luck with your build :beer:
 



Down with Umbrella

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The Efest work pretty good. I had a lot of voltage drop and battery problems with a build with that diode.
The Imren tested best and worked best, followed by an LG battery I had gotten from Larry, the Efest came in third best followed by a bunch of Panasonic and sanyo batteries.
There's another forum that had a thread about battery comparison (CPF I think) interesting info. Larry got back to me.
Pretty soon I'll be like the rest of you and have more batteries than I know what to do with! I keep ordering them.
 

IWIRE

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Interesting. Hopefully somebody on here will try them and report back. I think the electronic cigarette people are really helping us see some amazing batteries. That was where I found out about Imren. I started searching the ecig forums for battery info :) I don't know of anything that taxes an electrical system like a heater does.
Thanks for the link :beer:

There's another forum that had a thread about battery comparison (CPF I think) interesting info. Larry got back to me.
Pretty soon I'll be like the rest of you and have more batteries than I know what to do with! I keep ordering them.
It's nice to have an assortment of batteries. I use the high capacity ones that aren't capable of delivering high current in my low watt builds, and the high current ones in my high watt builds.

I used to swear Panasonic was the best battery out there until I built the 5.6w 445 using one 18650. Then I had to find something that would work. The build pulls like 5.5a - 6a at the tail cap. I thought a 10a rated battery would work fine but it wouldn't. It would work, just the battery voltage would drop under load,

I even took the wrapper off an Imren , Larry and I were wondering if it was a rebranded cell. It appears Imren actually makes the cell. It's an amazing battery.

I had bought one of those chargers they had in the GB thread. Measures internal resistance, measures the capacity of a battery. Really a handy charger to have.

I had to go to harbor freight yesterday and get one of those plastic parts bins to store batteries under my bench. My bench was getting cluttered :)
 

Papango

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What kind of driver would be able to deliver the required 4+amps for powering this diode at 5W ?
Need to use 2 x-drive ?

I will use wall adapters and not batteries though .
 

DTR

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Most do 5W with the 3.5A X-drive plus or minus a few hundred mW. Best option in my opinion.:beer:
 

rhd

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Isn't the tip of the power curve on these at 4.5A?
 

DTR

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Yep my original testing shows you start loosing power @ 4.5A+. If you figure a good overdrive current is about 10-20% back of foldback that would be around 3.6A-4A as a max. The 3.5A X-drives are a buck driver which is readily available. There are some available boost drivers that go up to 4-4.5A but those have pretty hefty requirements like a near 10A current draw off a single Li-ion but these 3.5A X-drives draws 2-3A which most switches and batteries can handle pretty easy which is why I like the buck drivers.:beer:
 

rhd

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Yep my original testing shows you start loosing power @ 4.5A+. If you figure a good overdrive current is about 10-20% back of foldback that would be around 3.6A-4A as a max. The 3.5A X-drives are a buck driver which is readily available. There are some available boost drivers that go up to 4-4.5A but those have pretty hefty requirements like a near 10A current draw off a single Li-ion but these 3.5A X-drives draws 2-3A which most switches and batteries can handle pretty easy which is why I like the buck drivers.:beer:

I'm with you on that. Buck is the way to go 100%, and Lazeerer's drivers are awesome.

BTW - impressive pricing on your NDB7A75s right now!
 

ricktrent4

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What kind of driver would be able to deliver the required 4+amps for powering this diode at 5W ?
Need to use 2 x-drive ?

I will use wall adapters and not batteries though .
I use and sell this one it works good and has 4 modes $19.99 eBay item number:
321455646668 You can see them on this 11w laser I made on youtube https://www.youtube.com/watch?v=dfZQNCkZ9bs
 
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ricktrent4

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Is that just a repurposed LED driver, or is that a driver you designed?
I asked the maker to set the amps to 4A to 4.2 max for me. they were used for LED but I have used this kind on my 3w laser set at 2.5A they run cool work good on 2 -18650 batteries.
On the 4A driver I have got a lot of diodes going to 5.7W ONE HIT 6W most around 5.5w
 

trussmonkey25

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I love how when you scroll through the power test pics fast enough the laser glare around everything steadily increases. thanks for doing these for us all:drool:

I feel like a 12 year old boy going through a Playboy for the first time. Ha ha ha. I have one of these big diodes in a labbie.
 
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FutureOne

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So realistically what's the lifespan of this diode running it off a 3.5A driver that's well heatsinked? how many hours of MTTF?
 




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