Laser pointer discussion. Read/write reviews of laser pointers and laser pointer companies. Learn about all types of laser pointers and lasers





Welcome to Laser Pointer Forums! If you are looking for a laser pointer or want to compare different laser pointer companies, you may want to check out the LPF Laser Pointer Company Database. The link will open in a new window for your convenience.








Green Laser Pointers by Category Blue Laser Pointers by Category Red Laser Pointers by Category
Yellow Laser Pointers by Category Violet Laser Pointers by Category Orange Laser Pointers by Category
Top Laser Pointers by Power - 1 Watt+ Top Laser Pointers by Power - 500mW+ Top Laser Pointers by Power - 250mW+
Laser Pointer Database High Power Laser Pointers Laser Pointer Diodes
Laser Technology Laser Pointer Parts Lasers by Wavelength
Top 10 Laser Pointer Companies Laser Pointer Company Database Visible Beam Laser Pointers


One laser store meets all your needs

























Go Back   Laser Pointer Forums - Discuss Laser Pointers > Lasers > Drivers, Test-load, Power Supply, & Batteries



LPF List of Laser Pointer Companies (link opens new window)



Reply
 
LinkBack Thread Tools Display Modes
Old 12-27-2010, 06:03 AM #1
Class 1 Laser
 
Join Date: Aug 2010
Posts: 58
Rep Power: 8
Hank is on a distinguished road
Hank Hank is offline
Class 1 Laser
 
Join Date: Aug 2010
Posts: 58
Rep Power: 8
Hank is on a distinguished road
Default Two Drivers in Parallel? Two batteries in Parallel?

If i connect two 18650 batteries in parallel, i should be able to draw 1.5Amp from each of the batteries safely to get a total draw of 3 Amps right?

What if say I connect two O-Like 1W 445nm laser drivers in parallel? I believe they are rated at 1.2 Amp, so i can safely draw 2.4A of current into a diode? Will something like that work? if not, why? Since the current going through each of the driver is still 1.2A.


Hank is offline   Reply With Quote







LPF List of Laser Pointer Companies (link opens new window)







Old 12-27-2010, 01:26 PM #2
Bionic-Badger's Avatar
Class 4 Laser
 
Join Date: Oct 2007
Location: Oregon, USA
Posts: 5,478
Rep Power: 2192
Bionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond repute
Bionic-Badger Bionic-Badger is online now
Class 4 Laser
Bionic-Badger's Avatar
 
Join Date: Oct 2007
Location: Oregon, USA
Posts: 5,478
Rep Power: 2192
Bionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond repute
Default Re: Two Drivers in Parallel? Two batteries in Parallel?

You can only do that if your batteries are properly matched, that is, they were made in the same batch of batteries and have the same discharge characteristics. Otherwise, one battery will inevitably discharge faster than the other, and the resulting voltage difference between the batteries will cause one to "charge" the other, which can also damage the battery. I would not try it.

A single 18650 battery ought to be able to source 3 Amps or so anyway, so you could get away with using just one. You could also look into some NiMH battery packs. They have very good current draw capabilities for motors and stuff.

Not sure how O-like's drivers work. They may be able to provide that much current, but they may also produce different voltages, which isn't good.
Bionic-Badger is online now   Reply With Quote
Old 12-27-2010, 03:24 PM #3
Cyparagon's Avatar
Class 4 Laser
 
Join Date: Sep 2007
Location: Wisconsin
Posts: 9,142
Rep Power: 9321
Cyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond repute
Cyparagon Cyparagon is online now
Class 4 Laser
Cyparagon's Avatar
 
Join Date: Sep 2007
Location: Wisconsin
Posts: 9,142
Rep Power: 9321
Cyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond repute
Default Re: Two Drivers in Parallel? Two batteries in Parallel?

^You're thinking series.

You could probably put a cr123a and an 18650 in parallel without problems.
__________________
A problem well stated is a problem half solved.
Cyparagon is online now   Reply With Quote
Old 12-27-2010, 03:56 PM #4
BShanahan14rulz's Avatar
Class 3B Laser
 
Join Date: Dec 2009
Posts: 3,175
Rep Power: 264
BShanahan14rulz has a reputation beyond reputeBShanahan14rulz has a reputation beyond reputeBShanahan14rulz has a reputation beyond reputeBShanahan14rulz has a reputation beyond reputeBShanahan14rulz has a reputation beyond reputeBShanahan14rulz has a reputation beyond reputeBShanahan14rulz has a reputation beyond reputeBShanahan14rulz has a reputation beyond reputeBShanahan14rulz has a reputation beyond reputeBShanahan14rulz has a reputation beyond reputeBShanahan14rulz has a reputation beyond repute
BShanahan14rulz BShanahan14rulz is offline
Class 3B Laser
BShanahan14rulz's Avatar
 
Join Date: Dec 2009
Posts: 3,175
Rep Power: 264
BShanahan14rulz has a reputation beyond reputeBShanahan14rulz has a reputation beyond reputeBShanahan14rulz has a reputation beyond reputeBShanahan14rulz has a reputation beyond reputeBShanahan14rulz has a reputation beyond reputeBShanahan14rulz has a reputation beyond reputeBShanahan14rulz has a reputation beyond reputeBShanahan14rulz has a reputation beyond reputeBShanahan14rulz has a reputation beyond reputeBShanahan14rulz has a reputation beyond reputeBShanahan14rulz has a reputation beyond repute
Default Re: Two Drivers in Parallel? Two batteries in Parallel?

I think this would be dangerous because there would then be a reverse voltage applied across the weaker cell. Keep them in series, keep them matched fairly well, or even safer, just use single cells or single protected cells.
BShanahan14rulz is offline   Reply With Quote
Old 12-27-2010, 09:32 PM #5
Cyparagon's Avatar
Class 4 Laser
 
Join Date: Sep 2007
Location: Wisconsin
Posts: 9,142
Rep Power: 9321
Cyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond repute
Cyparagon Cyparagon is online now
Class 4 Laser
Cyparagon's Avatar
 
Join Date: Sep 2007
Location: Wisconsin
Posts: 9,142
Rep Power: 9321
Cyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond repute
Default Re: Two Drivers in Parallel? Two batteries in Parallel?

Quote:
Originally Posted by BShanahan14rulz View Post
there would then be a reverse voltage applied across the weaker cell.
Best not to ever charge batteries then, since it applies an even greater reverse voltage
__________________
A problem well stated is a problem half solved.
Cyparagon is online now   Reply With Quote
Old 12-28-2010, 03:57 PM #6
Bionic-Badger's Avatar
Class 4 Laser
 
Join Date: Oct 2007
Location: Oregon, USA
Posts: 5,478
Rep Power: 2192
Bionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond repute
Bionic-Badger Bionic-Badger is online now
Class 4 Laser
Bionic-Badger's Avatar
 
Join Date: Oct 2007
Location: Oregon, USA
Posts: 5,478
Rep Power: 2192
Bionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond reputeBionic-Badger has a reputation beyond repute
Default Re: Two Drivers in Parallel? Two batteries in Parallel?

Quote:
Originally Posted by Cyparagon View Post
^You're thinking series.

You could probably put a cr123a and an 18650 in parallel without problems.
No! That is not a good thing to do. The two batteries have completely different capacities which guarantees that they will change voltage at different rates.

I did mean parallel. If they're in parallel, and one has different discharge/voltage characteristics, the other cell has to compensate in order to maintain the same voltage at the terminals. This is why you need to have matched cells if you need them in parallel, or else the differences in the batteries will have a detrimental effect on the overall circuit. You might as well just stick with a single cell in that case.

Read up on these things before making erroneous and possibly dangerous statements.
Bionic-Badger is online now   Reply With Quote
Old 12-29-2010, 04:37 PM #7
Cyparagon's Avatar
Class 4 Laser
 
Join Date: Sep 2007
Location: Wisconsin
Posts: 9,142
Rep Power: 9321
Cyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond repute
Cyparagon Cyparagon is online now
Class 4 Laser
Cyparagon's Avatar
 
Join Date: Sep 2007
Location: Wisconsin
Posts: 9,142
Rep Power: 9321
Cyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond repute
Default Re: Two Drivers in Parallel? Two batteries in Parallel?

They will both discharge at appropriate rates. If one is slightly higher in voltage at a given time, it will provide more current (since the voltage is higher) and that will lower the voltage. It will also work to equalize the voltage of the lesser cell by charging it very slightly. I'll perform a test if you like. What would you like me to measure? Would current/voltage of each cell on a 2.7Ω load as well as temperature be enough to convince you?
__________________
A problem well stated is a problem half solved.
Cyparagon is online now   Reply With Quote
Reply





Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On











Loading








Green Laser Pointers by Category Blue Laser Pointers by Category Red Laser Pointers by Category
Yellow Laser Pointers by Category Violet Laser Pointers by Category Orange Laser Pointers by Category
Top Laser Pointers by Power - 1 Watt+ Top Laser Pointers by Power - 500mW+ Top Laser Pointers by Power - 250mW+
Laser Pointer Database High Power Laser Pointers Laser Pointer Diodes






Privacy Policy | Advertising Disclaimer | Terms of Use


 


All times are GMT. The time now is 05:38 AM.


Powered by: vBulletin
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO
Privacy Policy | Advertising Disclaimer | Terms of Use
Copyright (C) 2017 Laser Pointer Forums, LLC