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do unprotected lithium-ion batteries = better performance?

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ixfd64

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As some of you know, I received a "Spyder I Pro" from Wicked Lasers about two months ago. Wicked Lasers' website says that a single lithium-ion (18650) battery should power the laser for about 90 minutes. However, my laser seems to go dead after less than 20 minutes of total use between charging the battery.

From what I've heard, this is because I have a protected lithium-ion battery that stops powering the device whenever the voltage falls below a certain level. In this case, will unprotected batteries give me the full ~90 minutes of performance?
 





billg519

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The protection circuit is there to prevent you from overdischarging the battery, potentially killing it. It also protects from potentially dangerous overcharging of the battery. Also, these circuits usually have a current limiter, set at 10A I think for 18650's. Do you have a quality 18650, or a lesser-rated one? There is a wide difference in the available mAh ratings, and some brands may not be up to the spec printed on the battery.
 
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ixfd64

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The battery has "2000 mAh" printed on it. I'm not sure which company made the battery, but it came with a charger made by a Chinese company called DSD.
 
billg519

billg519

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So this battery at best can deliver 2A for 1 hour. Have you measured the current drawn from the battery when the laser is operating? (Remove tailcap and use a DMM on 10A setting.) If your laser draws 1A, it should last 2 hrs, if it draws 2A it should last 1 hr, etc. Measuring the current draw will let you figure out if you have an underspec or even faulty battery.
 
LarryDFW

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ixfd64;

I think the problem is with the "poor quality" of the batteries.

Good quality unprotected Japanese batteries will deliver the rated mah easily.

LarryDFW
 
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nikokapo

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Also, take into account that low temperatures tend to drain batteries faster.
 
Cyparagon

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Well, assuming the stated capacity is accurate, it would last 80 minutes, but those values aren't accurate. It draws <1.5A according to Wicked's site, so that would make the capacity closer to 500mAh. Ouch.
 
T_Warne

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Can someone please recommend a reputable place to buy quality batteries?
 
Mohrenberg

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look at LarryDFW's signature (he posted above), he is selling 2400mAH sanyo 18650 batteries for $7.50 ea.

they ship from texas so it will get to you quick too.
 
bobhaha

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hey guys.. quick question, if i have two batteries in series, it boosts the voltage, but does the mAh increase too? Or is it only when you place them in parallel with no voltage boost?
 
billg519

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To increase the current, yes the batteries have to be in parallel. In series, they can only pass the current of one cell, but the voltage is additive.
 
bobhaha

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To increase the current, yes the batteries have to be in parallel. In series, they can only pass the current of one cell, but the voltage is additive.
Click to expand...

HUH?? wrong way around man... btw I wanted to know about the mAh not the voltages
 
Cyparagon

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The capacity will be equal to the lesser of the two batteries in series, but the voltage will be the sum of both batteries. Two 2AH 3.7V in series is equivalent to one 2AH 7.4V battery. Two 2AH 3.7V in parallel is equivalent to one 4AH 3.7V battery.
 
daguin

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Just a thought, but is there a "protection" circuit in the laser as well? Would running the voltage through two protection circuits effect this?

Peace,
dave
 
bobhaha

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The capacity will be equal to the lesser of the two batteries in series, but the voltage will be the sum of both batteries. Two 2AH 3.7V in series is equivalent to one 2AH 7.4V battery. Two 2AH 3.7V in parallel is equivalent to one 4AH 3.7V battery.
Click to expand...

Kk cool, got it! Thanks!!!
 
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