520nm Build Question

[sellersmd]

I'm building a 520nm using the following:

(1) Osram PLP520-B1 diode in aixiz module with 3-element glass lens from DTR
(1) Micro Boost driver set at 550mA from flaminpyro
(1) contact board from flaminpyro
(1) copper heatsink from Survival Laser USA
(1) C6 Host and drilled pill from Survival Laser USA

The micro boost documentation (https://illuminationsupply.com/Micro%20Boost%20Drive%20V1%20manual.pdf) says that input voltage should be between 2.7 and 5.5V, and can be up to 6.4V with a diode in series.

I'd like to use 2 x RCR123a from Survival Laser USA. Link: RCR123A Rechargeable Batteries.

The site lists these batteries at 3.7V each, so 2 x 3.7V = 7.4V. This is only my second build, so I'm not quite savvy enough on the electric theory yet. What diode should I put in series between the battery and the driver power input (as per the micro boost documentation) to make this thing work and not kill my diode? Would other batteries suit my purposes better? Would I be better off running this thing off of 1 x 3.4V 18650? Thanks in advance to everyone for their help and suggestions.

 

[Pi R Squared]

Do not attempt to run that off 2 batteries! Use one 18650 only.

Alan

 

[crazyspaz]

As Pi said- do NOT use 2 li-ion cells. If you really want to use 2 cells, you would have to use two 3 volt CR123 batteries.

 

[sellersmd]

Thanks for the responses, guys. Is there a specific reason not to use two li-ion cells? The only reason I was planning on using two is I thought I read somewhere that if I used 1 x 18650 that it would have to dissipate a lot of the energy as heat or something and it generally wasn't a good idea.

Another question:

Why is a CR123 a 3V battery and a RCR123a a 3.4V battery? I assumed they were the same thing.

Thanks again guys, and please forgive my ignorance!

 

[Pi R Squared]

Thanks for the responses, guys. Is there a specific reason not to use two li-ion cells? The only reason I was planning on using two is I thought I read somewhere that if I used 1 x 18650 that it would have to dissipate a lot of the energy as heat or something and it generally wasn't a good idea.

Another question:

Why is a CR123 a 3V battery and a RCR123a a 3.4V battery? I assumed they were the same thing.

Thanks again guys, and please forgive my ignorance!

You must never use 2 Li-Ion cells with a boost driver, boost drivers use only one battery and boost the voltage higher to whatever is needed.

As for the 123 batteries, one is rechargeable and the 3V ones are not and would be expensive to use.

Alan

 

[sellersmd]

You must never use 2 Li-Ion cells with a boost driver, boost drivers use only one battery and boost the voltage higher to whatever is needed.

As for the 123 batteries, one is rechargeable and the 3V ones are not and would be expensive to use.

Alan

Thanks for the response. I will go ahead and use 1 x 18650. Any other tips or pointers for the build?

 

[Pi R Squared]

Thanks for the response. I will go ahead and use 1 x 18650. Any other tips or pointers for the build?

As you have already chosen the parts you will use I can't think of anything just now. All those parts will work together but please read a few build threads to get an idea what your doing and the potential problems you may have, people frequently do something wrong on their first build and its usually expensive. Best of luck and show us the results once its finished.

Alan

 

[sellersmd]

Thanks for the advice, Pi. This is actually my second build. First one was a 1.6W 445nm build in a C6 host as well. That one went well and is an awesome laser, I'm just not really savvy with the micro boost.

 

[bdgreenb]

be sure to short the positive and negative outputs on the driver( by just touching both pads simultaneously with a wire) before hooking it up to your diode. Get one of the panasonic 18650s, and remember that your mAh on your battery will be lower than your actual Laser hours, due to the voltage boost. Boosts are great tho, unlike linear drivers, they will keep a solid current flow until the voltage is too low and it will stop(>2V). i.e. if you meter a boost driven system until shutdown it will give you about the same output the whole time, whereas linears will slowly but surely lower in power.