Batteries. Sanyo Elenoop not so great for Laser?

Hi,

I´ve bought a cheap green laser on Amazon last year and for the price (about $10) i think it´s not bad at all.

The one i´ve bougth is this one (but now it´s cheaper, don´t know if it´s still the same model, however the design is the same):

http://www.amazon.co.uk/exec/obidos/ASIN/B003SDUTH0/ref=ox_ya_os_product

The laser isn´t bad at all for the price. It claims 1mW but i really don´t know if it´s only 1mW. It´s really bright and i could see the spot at least at 500m. The beam it´s visible too.

However, the laser was always a little bit inconsistent. Sometimes it´s really shine and visible at least at 500m, other times i barely can see the dot at a few meters away (like 10 or 20m).

I have no sure yet but i think the problem gets worse when the batteries aren´t new or fully charged. When they are new i think theres no problem but after 3 or 4 minutes of use, i think theres where the problem starts.

I´ve read a lot of positive reviews about the Sanyo Eneloop, and when i bought laser, i bought 4 AAA (the laser uses 2xAAA) Sanyo Eneloop too.

However i´ve notice the Sanyo batts aren´t so "powerfull" like the Alkalines ones. I think it´s because the voltage. It seems the laser requires more Voltage than capacity. Even when full charged, the laser isn´t as powerfull as with new Alkaline and it seems to drop power even faster.

This make any sense? I´ve always read that Eneloop are one of the best batts for lasers but it isn´t what i´m experiencing.

Theres any 3V rechargeable battery i can adapt on laser?

NiMH are nominally 1.2v and 1.4v when fully charged compared to the 1.5v of an alkaline. Some people have modded green pens to use a single 3.2v 10440 LiIon but when fully charged their 3.7v may destroy the driver and/or diode.

Battery Capacity 800 mAh. Min - 750 mAh
Battery Quantity 4
Battery Type AAA
Chemistry NiMH
Voltage 1.2V

I believe non rechargeables are 1.5v... That is what probably makes them not work in the laser.

IIRC most green modules used in pens like that need about 3v to work so if you're using NiMHs you're at most feeding the driver 2.8 to maybe 2.9 volts which can make a big difference.

A couple years ago I did some testing with some "Duraloops" (Eneloops rebranded as Duracells) in a 405 and 532 pen and there was a small difference in the 405 from 45 to 48mw but the green jumped from 26 to 38mw almost a 50% power gain. I honestly didn't notice much if any change in brightness from the laser and figured the power difference was mostly from increased IR. To be honest since I had just received a much better green laser I didn't bother redoing the tests while filtering the IR out. I still use them in those pens because the benefits of being rechargeable make up for the small power loss in the 405nm and the green has since been replaced by better lasers so I don't mind its lower output.

You can pick up rechargeable alkalines these days that still have a nominal voltage of 1.5V, but their capacity is usually a fair bit lower and they're really intended for really low draw, high lifetime applications. You also need a special charger for them.

Check out NiZn rechargeable batteries. You will need a special charger, but they are supposed to work great and are 1.6 volts each. IIRC the main brand that sells them is powergenix.

You can use LiFePo4 batteries as their voltage is essentially the same as an alkaline but the capacity of the AAA ones I have are terrible (something like 200mAh).
I've done lots of testing with different voltages and seen some VERY dramatic increases in output depending upon many factors including manufacturer of the unit. Inexpensive units such as ebay pens are a crap shoot especially with 532nm.
Most of my lasers will run off a higher voltage such as running a 10440 and dummy cell but some will not. What tends to happen if it doesn't like the extra voltage is the output will momentarily be quite bright and then drop suddenly and not come back up.

Here is another case where a bench power supply is useful. Green pointers use a linear driver. If you power the pointer with a power supply and increase the voltage until the current no longer increases, you have found the optimal voltage to drive the pointer at. The good pens (CNI for example) will have good regulation at 2.4V and above. The core I have will even run at down to 2.1V. If your pointer doesn't supply enough current with NiMH cells, that means it will only use a small portion of the alkaline cells' charge anyway. If you're considering spending cash on exotic lithium chemistries, I would suggest getting a better pointer instead.

I have both a variable DC power supply and a variac (although the variac isn't used for this aplication). Can't even begin to say how much I've used the bench unit since getting into this. Listen to Cyparagon, it is a wise investment. Nothing beats knowing the reality of where things really stand by testing/setting with the bench unit and not having to guess.
And, as he mentioned, there's nothing like a good quality pen (I happen to be VERY fond of them) in comparison to the no name units. I have all of my high quality ones seperated in their individual boxes.