Energizer Energi To Go Step Up Circuitry

http://www.energizer.com/products/energi-to-go/cell-phone-charger/Pages/cell-battery-charger.aspx

On sale at Circuit City for $4.17 each (regular price around $16). The 2 AA Lithium batteries alone cost $4 to $6. So great deal.

The charger steps up 3v from 2 AA to 5.5v to charge a cellphone. The step up circuitry inside must be good for something. I figure I could use it to drive an LED.

Any suggestions?

i drive an led off of a cheap china single cell one of these, the output current was about 160ma.
this thing might be (should be) a bit higher than that.

the claim is that its as fast as a "wall plug" which would be 500-1000ma for some devices.

and 2 hour charge time , which would be about 500-750ma for lots of standard battery cell phones.

soooo, its probably 250-1000ma , and i bet its more like 250-500ma.

found some faqs and manuels, but no "tech Specs" sheet.

my cheap slow china one doesnt run well with alkalines as the voltage drops to quickly, if this thing goes much faster (like 500+) it probably really needs the lithium cells too. good way to SELL high priced batteries.

would it make a LED driver? chances are VERY good that it could, my guess is it wouldnt be as high as something you could buy specifically designed to drive an led, if you needed high drive currents, but would be perfect for more nomalised drive currents.

linkey to the deal at curcuit city
http://www.circuitcity.com/ssm/Wire...61+20016441+20014521/rpem/ccd/categorylist.do

a reviewer said the thing charged faster than her wall plug, so that indicates a high output, but i never found any testing specs for the actual miliamps :-( and gave up searching.

Additional info. I found that using NiMH on these won't work. Well, it runs for a while (charges my cell phone). But it quickly dies, charger stops charging, blue light stops blinking and my cell phone stops indicating it is charging. Voltage drops below a certain threshold and the circuitry won't charge anymore (my assumption, did not really measure voltage)? Probably because NiMH have a lower voltage to begin with.

ltiu said:

Additional info. I found that using NiMH on these won't work. Well, it runs for a while (charges my cell phone). But it quickly dies, voltage drops below a certain threshold and the circuitry won't charge anymore. Probably because NiMH have a lower voltage to begin with.

Click to expand...

What type of NiMh batteries did you try? Just curious if Sanyo Eneloops would perform any differently in this device?

Edit: What a great deal on these... glad I checked this site... I just bought 2 of them!

BlackDecker said:

What type of NiMh batteries did you try? Just curious if Sanyo Eneloops would perform any differently in this device?

Click to expand...

I used Eneloops and Ray-O-Vac Hybrids.

I have actually had one of these Energi-To-Go for many month now and I have used this quite a bit while travelling.

My experience:

During my one trip, I forgot to bring along my cell phone wall charger. But I had some Eneloops and Hybrids plus an Eneloop charger for my flashlights. So I used these for the Energi-To-Go thinking I do not want to waste an e2 Lithium L91 charging my cell phone. I charged the Eneloops and Hybrids. Fresh off the charger, I popped these into the Energi-To-Go. The charging lasted no more than 15 minutes per set before the charger stopped charging. I did this a few times using different Eneloops and Hybrids thinking maybe it's a battery issue. But I kept on noticing that Eneloops/Hybrids do not last long when charging my dead or near dead (one battery bar left) cell phone. My cell phone would not be fully charged yet when the charger would turn off indicating the battery (the Eneloop/Hybrid) is dead.

Whereas when I used e2 Lithium L91, I find I can at least charge my cell phone twice from dead or near dead (one battery bar left).

ltiu said:

I used Eneloops and Ray-O-Vac Hybrids.

Click to expand...

Thanks for the info! I was hesitant to buy the 'Energi to go' at $20, but at only $4.17, it's worth a try. And like mentioned above, it's worth it for the L91 Lithium batteries in the pack, if anything.

Eneloops, Rayovac Hybrids and a few old Energizer 2300mah batteries are all I have as far as rechargeables.

It's not a total loss, it can still charge your cell phone with Eneloops, but you need to go through maybe two or three sets to fully charge a phone. But often times, you don't need a fully charged phone to start using it.

If you are an electric tinkerer. Getting the charger for the circuitry will give you hours of fun.

Thanks for the heads up! Just ordered two of these. :twothumbs

Does anyone think that connecting 2 of these Energi chargers together
in a way so with NimH batts in the 1st one supply voltage by some
homemade wire rig into the empty battery compartment of the 2nd Energi and thus make sufficient voltage from the 2nd to charge a cell phone battery???

You'd save by using NimH rechargables and not consume the cost of
2 AA lithiums.
Wonder if there is room inside to cram the guts from 2 of these Energi's
inside if this scheme works.
OK! Another hopkins kludge idea but thats the job folks!

hopkins said:

Does anyone think that connecting 2 of these Energi chargers together
in a way so with NimH batts in the 1st one supply voltage by some
homemade wire rig into the empty battery compartment of the 2nd Energi and thus make sufficient voltage from the 2nd to charge a cell phone battery???

You'd save by using NimH rechargables and not consume the cost of
2 AA lithiums.
Wonder if there is room inside to cram the guts from 2 of these Energi's
inside if this scheme works.
OK! Another hopkins kludge idea but thats the job folks!

Click to expand...

I only use this for emergencies or when camping ... in an area without outlets but with cell service.

So I have actually only used 2 Lithium AAs in 6 months. I have used maybe about 24 Lithiums in my flashlights (for caving) in that same time!

edc3 said:

Thanks for the heads up! Just ordered two of these. :twothumbs

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Only 2?

I got 8!

Too good a deal to say no to.

There are four versions of this for different kinds of phone, and not all have the same list price. Only the Nokia one is really expensive.

Which one steps up to 5.5 V?

The fully charged voltage of Ni-MH [1.25?] is that of a nearly flat L91 which starts at 1.7 volts. The device was designed, apparently, to sell L91's and probably gives a very short run time on alkalines.

I wonder if you can use 2 or 3 Ni-MH in an external holder. I did that with my rechargable beard trimmer that no longer held a charge.

Guess it depends on the phone you are trying to charge. I have a old Nokia tracfone that has been attached to the Energi to Go using Eneloops for over 45 mins now and the Eneloops haven't died yet.

Mr Happy said:

There are four versions of this for different kinds of phone, and not all have the same list price. Only the Nokia one is really expensive.

Which one steps up to 5.5 V?

Click to expand...

I bought the Nokia version of the Energi to Go at Circuit City today for $4.17 - same price as the other 2 models CC has available.

I dropped by my local Circuit City and looked for them in vain. None of the sales assistants could remember ever seeing them. Bummer.

What I meant about the price is on the Circuit City website. The Nokia one has a normal price before discount of 21.99, whereas the others have a price before discount of 7.14.

I tried to buy 2 of the Sprint/Samsung models, and the CC website said all 3 stores in the OKC area had them. Placed the order online, only to be told when I arrived at the local store that they only had the Nokia one left.

You can't trust the CC website, so buyer beware.

I bought one of these, not all that effective for my samsung. it will fully recharge the phone in one setting but thats probably all the cells could hold for, the remaining capacity they can be used to top off your battery if theres only one bar or so missing

I find the design rather flaky, the body consists of an interlocking clamshell held together by molded latches on the inside and the two end caps. the battery door is especially sensitive to spring pressure from the battery. the manual says not to take the batteries out for 15 minutes after the phone is removed...when it popped open a couple times during charge it wouldn't function properly, and took awhile to reset itself.

it wont use anything but the L91 lithium AAs, I even hooked it up to the bench power supply, the indicator LEDs would blink, but no charge

for $20 I thought why not...haha
I took it apart after the battery door's latch snapped off...the circuit board's photographable if anyone needs a pic

I wonder if (protected) 14500's would fit and run safely? I have one that is now collecting dust because I broke my Motorola.

These things are insane. Maybe they do something useful because of the stupid way cell phones are designed, but it would make a lot more sense for someone to make a phone that runs directly on nimh aa's.

Anyway, most phones these days have a 5v charge input, which corresponds nicely to four nimh aa's or aaa's. So rather than a boost converter I'd probably just put together a 4-cell pack with no converter.

Alternatively, the phone's lithium ion cell is 3.6V and maybe there is a way to substitute three NiMH cells.