Battery Life: Booster vs Regulator

[sgtdisturbed47]

I started building my own mods back in October, and it's been a blast. I have a few nice mods built so far, as well as some re-builds. I haven't been flaunting them on here, but soon I'll have a tester from ECF play with a couple of them.

Anyway, I have some strange experiences to report. First, the popular Texas Instruments ptn04050c Booster. Using a single 14500 900mAh battery with this booster has been pointless, as the battery life is awful. I've tried it with and without capacitors, and the same result occurs. I have also put 2 14500's in parallel to try and get better battery life, and that still didn't help much. I'll get maybe 4 hours of use before the booster starts whining and the power cuts down considerably.

With a linear voltage regulator, my battery life is doubled. Having the 2 batts "stacked" in a series, by my understanding, gives me 2x the voltage but at the same 900 mAh. Weird that I am getting 6-8 hours of use out of such a setup vs a booster with 2 batts in parallel.

Using a switching regulator, I get 2x the battery life vs a linear regulator. I put my batts on the charger after 36 hours of use, and I am a very heavy vaper.

Why are boosters even an option when the battery life is horrible with them? Maybe I am using the wrong battery and maybe it needs to have a high-drain battery, but even so, why bother with a booster if special batteries have to be used. I'd rather build mods using regulators.

 

[Java_Az]

If you hooked up two amp meters to the boost chip , one on the battery side and one on the output side you would see that the input is going to be using more amps then the out put. The higher voltage comes at a cost of your mah. Same is true when bucking down but in reverse the input will be reading lower amps then then output. Boost converters in general are not as efficient as buck converters but they are not too far apart. Not sure why your getting that much of a difference. Should be around 10% not 50%.

Looking at the mah rating of two batteries is parallel and two in series is very deceiving. You think your loosing power by putting them in series because of the mah rating 900mah for series 1800 mah for parallel. But the 900mah is @ 8.4 volts and the parallel is @ 4.2 for fully charged batteries. They actually have the same amount of watts. Say you bucked the 8.4 volts down to 4.2 with the regulator and have a resistive load. The input amps from that batteries would be half of the output amps Plus what ever your losing in efficiency So if your reg is 95% efficient add 5%. Not sure if this makes any sense took me awhile to wrap my head around it. But thats how it works

 

[sgtdisturbed47]

It could be that my batts just don't like the stress of using a boost converter, and maybe that's why they don't do so well with them. Using a switching regulator seems to be the only way for me to get the best battery life. Then again, these aren't special batts. They came with a DSE-905 that died. I doubt they are even protected (they don't look like it).

Oh, on the subject of batts, I have a set of TrustFire 14500's that I would rather use, but every time I go to put them in a mod, their protection kicks in. Whether it's using a boost or a buck, they don't seem to work. Pieces of garbage. Also, they are too long to use in any AA batt size box, unless I tear the box apart and re-fit the batt connectors to make room. Are all protected batts like that?

 

[Java_Az]

Yeah boosting to 5 volts would for sure stress one 14500 out but i think two could handle it. I would look at the trust fire spec sheet but i am sure it is full of lies like their mah ratings. Protection shouldnt kick in unless you have a short or they are low on voltage or your pushing them passed the protect rated amps. Might want to double check with a meter for shorts.

 

[AttyPops]

Why are boosters even an option when the battery life is horrible with them? Maybe I am using the wrong battery and maybe it needs to have a high-drain battery, but even so, why bother with a booster if special batteries have to be used. I'd rather build mods using regulators.

Yeah, I got into a bit of a "discussion" on this a while back. Java's buck vs boost answer above probably nailed it right on the head. Maybe Java or some of the other pros can explain it better, but you are basically "robbing Peter to pay Paul" with a booster. You're trading increased amp draw for voltage boost, and losing some efficiency to boot. The discussion was with an 18650 tho, which is probably more suited to that application. The increased capacity (and size) is a trade off between the 2 14500s (size wise). 1 18650 is heavy enough; 2 18650's are a beast. So I just go with 2 14500's and regulators... but that's me.

The switched mode vv power supplies (modules) are great tho. Last I knew they were $25.00 and I just haven't the need to spend that when $10.00 gets me an extra set of batteries. There are other switched regulators, as you mention. Switched mode is most efficient, as I understand it. Hell, right now I'm using linear regulators and they get me through 1/2 - 3/4 of the day. So 2 pairs of batteries are all I need for portable 5v vaping. I just haven't gotten them stuffed into a 2xAA box with atty and button and regulator yet. 3xAA so far.

Sooo.... I guess the appeal is the 1 18650 boosted to 5v in a decent form factor. No idea how long it would last tho, maybe someone will post some results.

Was the 4 hours with 2 14500's, or just the one?

So anyway, I'm watching this whole booster type thing with great interest as to the results. I have an 18650 sitting around that will become either a 3.7 volt or 4.x/5v/vv mod. Thank you for posting your info. Keep us informed as to your results!

And thanks Java_Az for your insights too!

And for reference on switched vv regulators:
http://www.e-cigarette-forum.com/forum/battery-mods/102419-adjustable-voltage-box-mod.html

 

[sgtdisturbed47]

Sorry, not TrustFire but UltraFire. Are they made by the same people? Sure seems so.

Was the 4 hours with 2 14500's, or just the one?

That was with 2 non-protected 14500's in parallel, and the same result with 2 UltraFire 14500's in parallel.

I have yet to try 10440 or 18650 batts, but I am definitely interested in the low profile of the 10440 and the longer life of the 18650.

 

[Erwin]

I wanted to bump this for opinions on the trustfire 18650 tf 2400 mah batteries with a booster chip. I was planning on using them in an upcoming build with the ptn4050 booster from ti. I was wanting to use a pair of them in parallel and see how long I could go between charges but this thread has me second guessing. Anyone want to enlighten a noob on whether this is a good idea? Like maybe someone who has done it already? Thanks guys.

 

[Java_Az]

I wanted to bump this for opinions on the trustfire 18650 tf 2400 mah batteries with a booster chip. I was planning on using them in an upcoming build with the ptn4050 booster from ti. I was wanting to use a pair of them in parallel and see how long I could go between charges but this thread has me second guessing. Anyone want to enlighten a noob on whether this is a good idea? Like maybe someone who has done it already? Thanks guys.

If your main goal is battery life your going to do better using a switching regulator and run the 18650's in series. You will get a bit of drop out at the end of that 18650 in series charge. My calculations show it will drop out to about 4.6 volts before the battery protection kicks in using a ptr08100w switching regulator. Data sheets seem to say the switching reg is 10% more efficient then the 4050. Real world the 4050 could be less i need to test mine out one of these days have a couple sitting here. But some folks have been getting poor results out of the 4050's. The 4050 also have a 2.4 amp rated max @ 5 volts so using LR's on them would be pushing them passed rated specs.

 

[Erwin]

No interest in using LR attys with it. Maybe I should just take my ptr08100 out of it's cheap battery box and put it into the wooden box I want to build with the two 18650's then. I will be watching to see if you are able to post up some real life specs on this java. Thanks

 

[Gummy Bear]

If you don't mind me chiming in,,,
I have a tube mod with a single 3600 mAh 18650 boosted up to 4.5v that runs about 6 hours of hard chain vaping.
And also a 2100 mAh 7.2 volt regulated down to 4.5v box mod, it goes 15 hours.
If I put the 4100 mAh 7.4 v battery in the box mod it will go 4 days.

 

[AttyPops]

.... I have a tube mod with a single 3600 mAh 18650 boosted up to 4.5v that runs about 6 hours of hard chain vaping......

The other batteries aren't spec'ed, so IDK what you mean exactly. But the mAh/usage info is interesting. Like Java said... regulators are better for lifetime... but they require 2 cells and up the form factor.

That's the kind of stat I'm looking for. What battery is it? 3600 mAh? really? It doesn't make sense to me (for my applications) to use dual 18650's.... too bulky for my taste. The one 18650 boosted is of interest. OTHO, I can get 8 hours or so from 2x14500s in a 3xAA box using a plain old regulator... but I haven't compared it using a single boosted 18650 yet. Which is really what the OP's question gels down to. "Why use a booster?"

I'd love to find a 2xAA box with enough headroom on top to get an atty connect, master switch, button, LED, and linear/switched regulator inside. Ambitious, but that would be a perfect form factor. The alternative, is a single boosted 18650 I guess.

 

[Gummy Bear]

AP,
The single 18650 is an UltraFire brand from ebay, so the 3600 mAh rating I'm sure is a lie but it is all I have to go on.
The 7.4 volt 2100 and 4100 mAh batts are camcorder batts.
The tube mod that runs the boosted single 18650 is more ergonomic for me than the box mod that is the only reason I made it.
My thoughts were that if the 2100 regulated battery lasts all day, a 3600 boosted battery should also last all day, Wrong.
and I'm sure that the true mAh rating of the 18650 is no where near true.

 

[Spliner]

I gave up using Trustfire/Ultrafire 14500's with a 4050 booster. I did however have some better luck with an IMR 14500 batt. I seem to get 2+ hours of vaping out of a single IMR 14500 with a 4050 boost, but I don't chain vape it. Seemed like the Trustfire/Ultrafire batteries would kick in their protection or drain too fast with the 4050 booster. I'll try and time it on a fresh charge and re-post an update but so far it's been about what I expected with the IMR's.

Spliner

 

[Nuck]

With both the proper caps placed close to the pins and the proper bat (4+ amp discharge) I get 30 hours of vaping with a 2.7 ohm 901 and about 18 hours with a 1.5 ohm 306. I consume 5 ml of juice with the charge.

I've tried a ton of batteries with this chip and the ones that give good performance are:

AW 2600 mah 18650
Tenergy 2600 mah 18650
Panasonic 2900 mah 18650 (unprotected but available wrapped in an AW version)

The AW IMR 18650 did not perform as well and was disappointing after only a month of testing.

The boost chip is far more efficient than any linear regulator and comes in very close to a quality switching regulator. You do, however, have to select the right power source of you're in for a lot of avoidable frustration.

 

[sgtdisturbed47]

I'm using 900mah (supposedly) and they are 14500's. With these, a booster gives me 4 hours max with 2 of these batts in parallel. You are pointing out 18650's which are a larger battery and longer battery life (900mah in series/~1800mah in parallel vs ~2600 mah is quite a difference). I'm sure if my 14500's were 2600 mah then they would get 3x the batt life. Apples and oranges are being compared here.

The boost chip isn't more efficient if it's eating my batts left and right and a linear regulator lasts all day, if not more, and a switching regulator can hold me over across 2 days of vaping. In a series, the batts are the same mah but 2x the voltage, so with that being said, a switching regulator is the best way to go and is far more efficient, and there's no way these boost converters come close to even a linear regulator in terms of efficiency considering the battery life I'm experiencing across all 3 platforms.

 

[Java_Az]

What kinda caps you running on that 4050?

 

[sgtdisturbed47]

What kinda caps you running on that 4050?

100uf 32v electrolytic, the same that I use on my linear and switching regulators.

 

[Java_Az]

100uf 32v electrolytic, the same that I use on my linear and switching regulators.

Thats what is recommended in the data sheet. Strange you should be getting better performance out of it. Maybe it is a bad module.

 

[sgtdisturbed47]

Thats what is recommended in the data sheet. Strange you should be getting better performance out of it. Maybe it is a bad module.

Believe me, I was praying that it was a bad module. Unfortunately, this batt life issue has occurred on all 3 of the boosters I built with.

 

[Nuck]

The mah wasn't the point. The point was that the batteries need to be able to provide 4 amps of continuous discharge. Anything less at the power drain we typical vape at will give disappointing results. Underrated batteries will starve the circuit for current resulting in mediocre vape and is sometimes accompanied by a whining noise. They will also stress the battery itself, dramatically reducing its life.

The relative efficiencies of the various methods are provided with each of the chips.

I'm using 900mah (supposedly) and they are 14500's. With these, a booster gives me 4 hours max with 2 of these batts in parallel. You are pointing out 18650's which are a larger battery and longer battery life (900mah in series/~1800mah in parallel vs ~2600 mah is quite a difference). I'm sure if my 14500's were 2600 mah then they would get 3x the batt life. Apples and oranges are being compared here.

The boost chip isn't more efficient if it's eating my batts left and right and a linear regulator lasts all day, if not more, and a switching regulator can hold me over across 2 days of vaping. In a series, the batts are the same mah but 2x the voltage, so with that being said, a switching regulator is the best way to go and is far more efficient, and there's no way these boost converters come close to even a linear regulator in terms of efficiency considering the battery life I'm experiencing across all 3 platforms.