Newest MintyBoost and DROID

[bbianchi]

Just completed my MintyBoost per the published instructions with no modifications in the resistor type or configurations. Works with my DROID.

I am using Duracell 1700 mAh rechargeables and I too get the hissing sound. Granted at this point it only correlates to the screen on the phone being on. Its as if its sending something dirty to ground or something and its making it back to the mintyboost. I have ensured all the PCB's parts are isolated from the tin with ductape as well as the foam adhesive. I don't really think this is anything to be concerned about as over the years I have experienced other electronics doing this same thing when charging.

Ill run some tests and let people know the results I see with the DROID and these specific batteries.

EDIT:
I Just tested this with my old Palm Pre and it also went right into charging mode. Used the 100K resistors in the "standard" Pull Up mode IIRC.

Brandon
NI6C

[adafruit]

sounds good,
is the hissing coming from the mintyboost or the droid?

[bbianchi]

From the MintyBoost. My guess is the inductance coil...

[adafruit]

yup, its not too bad, its just resonating. happens sometimes

[malsbury]

Just want to add that I also had success with the Version 2.0 MintyBoost in the Pull-up configuration with the 100k resistors.

I had a larger tin on hand and knew that the Motorola Droid would require a little more juice than 2 AAs could provide, so I placed two pairs of AAs in parallel. Everything just fit with the side load holders I found at my local Radio Shack. So now I can run it with 4 2500mAh rechargeable batteries.

If you'd like to see any pictures of the build or it in action I posted them here:

http://picasaweb.google.com/malsbury/MintyBoost

Thanks for such a neat little product and such easy to follow instructions.

-malsbury

[optik678]

I just wanted to add that I just finished a stock build of Mintyboost v2.0 and it works with my Motorola Droid (Milestone) as well.

[GieltjE]

Just want to add that I also had success with the Version 2.0 MintyBoost in the Pull-up configuration with the 100k resistors.

I had a larger tin on hand and knew that the Motorola Droid would require a little more juice than 2 AAs could provide, so I placed two pairs of AAs in parallel. Everything just fit with the side load holders I found at my local Radio Shack. So now I can run it with 4 2500mAh rechargeable batteries.

-malsbury

A: Can I use the stock mintyboost to acquire this "Pull-up" configuration with 4AA batteries, or do I need to modify it some?
B: How much charge can you get out of this configuration?

[adafruit_support_bill]

To answer your question 'A': The kit comes with a couple different values of pull-up resistors - including the 100K. When you build the kit, you install the appropriate resistors for your device. The MintyBoost web page lists the known compatible (and known incompatible) devices.

http://www.ladyada.net/make/mintyboost/index.html

[NegatedVoid]

How long does it take to charge the droid?

Mine goes into charge mode but never seems to actually charge (perhaps charging at the rate the phone uses it in sleep mode).

[bp19406]

I just put together my Mintyboost kit v3 and attempted to charge my Droid X. All the tests I performed during the final assembly were within the normal ranges and my Droid X acts like it is charging. However after several hours the battery level does not increase. I started charging at 40% power and that's were it remains. I tried a couple sets of brand new 1.5 volts alkaline batters, tried fully charged 1.2 volt 2650 mAh rechargeable batters, and each time the phone acts like it is charging but the power level never increases.

The chip gets hot like it should when charging, its stay totally cold with batteries in when not hooked up to the phone.

I even tried putting a blob of solder between the two middle pins to make a USB spec charger and that did not seem to make any difference, except that the circuit does not seem to get nearly as hot as it did before.

Any suggestions?

[HamNinja]

@bp19406

My first question would be to ask if you are using the phone at all...

My guess is that the Droid X uses a lot of power, and if you're using it at all while it's charging (ie with the screen on)... the MintyBoost could simply be playing the keep up game. Even with fresh high-draw batteries the chip doesn't seem to be designed to efficiently provide 4-500mA of current to the USB device- which is why it gets hot while 'charging'.

This would seem normal to me if you were using the phone or if it was doing something that uses a fair amount of power. If you can disable radios, apps, and leave it alone for a while during charging-- the percentage should go up.

---------------------- If not, check the current draw at the battery and USB out [while charging] and report that info.

Hope this helps somewhat,
HamNinja

[bp19406]

I do not use the phone while charging and yes the droid x is a power hog. I have tried charging with the phone on and off. Since my first post I was able to get the phone to increase its charge by 20%. From 30% to 50% total charge, according to the phone. Basically I looked for the strongest two AAs I had. They were 1.56 volts. Used them and like I said I got a 20% bump after which the phone no longer registered the mintyboost (this is when using the 2 AA holder that came with the mintyboost as you will see below I tried going to a 3 AA holder). I rechecked the batteries and they had depleted to 1.22 volts each.

My output voltage with no load is 4.99 volts at the USB (of course that is the same with either battery holder) and 4.8 volts at the battery (this is with the 3 AA holder I added). I picked up the 3 AA battery holder in the hope that the additional battery will help get better results. Again I got a 20% bump (20% to 40% on the phone) before the batteries were drained. Basically after about 30 minutes I notice the chip and batteries begin to cool and although the phone still says it is charging I don't get any additional increase. My output under load is around 4.36 volts at the USB when I first start charging and that drops to around 4.22 after 15 minutes, and down to 3.85 after 30 minutes. Under load after 25 minutes the voltage of the 3 AA batteries in the holder is around 2 volts, no load and its around 3.7 volts.

I think that part of the problem is that the batteries get so hot that they are really losing efficiency, in addition the Droid X seems to suck'em down like cold beer. Once the batteries cool they bounce back some but they don't seem to have enough juice left to charge the Droid X.

Tried Duracell and Rayovac batteries. Perhaps if I found a better battery I would have better luck. Or maybe 20% is about the best I can hope for.

[HamNinja]

Frankly, if I wanted some long lasting batteries, I would just do something like extract those high capacity 'F' cells from certain 6v lantern batteries and hook them up in a 2x2 configuration. That would provide just under 10x the available power of a couple strong alkaline batteries. Of course making sure the battery output is under 5-volts....!

... back to the subject at hand, I am curious as to how long your phone's battery lasts (without a boost). I would expect a MintyBoost with 2 fresh brand name alkaline AA batteries to get you nominally about a 50-60% charge. We must also assume that even when not being used, the phone drains a fair amount of power making occasional network checks with it's radios and whatever background programs are running. I could see that dropping down, but all the way down to a mere 20% does seem a bit low.

[bp19406]

Without a boost my Droid X with the standard battery (3.7 volts 1540mAh) lasts a day and half to two days without needing a charge. I charge it when the battery drops to around 20-30% power and always recharge to 100%. I knew getting into the phone it would be a battery hog and it is. Not really a problem for me and maybe I will upgrade to the extended battery at some point. I never keep wifi or bluetooth on unless I am using them and I use the power saving feature that Android Froyo offers, such as turning off the data connection at night.

Best as I can tell I get about the same battery life as other people I know that have the droid x, some that are big internet users and texters get even less life than I do.

Thanks for your suggestions, I am going to play around a little more with it and see if I can get slightly better results. I was really looking for a light compact charger to boost my phone on weekend backpacking trips. I like having the phone for its GPS and to make an emergency call if needed, assuming I am in an area with cell coverage. I can always buy another battery for the phone or buy another commercial battery charger, in fact Verizon sells one that Motorola makes.

[3club]

Hi all,

I basically have same needs as bp19406. I'll be taking my Droid X backpacking for two weeks and want some way to charge it.

Last year, I bought this charger http://www.amazon.com/Portable-Battery- ... 758&sr=8-6. At first I thought it worked okay, but last year I didn't have the Droid X.

I use rechargeable batteries, Energizer and Eneloops. I can only get about a third of a charge from a pair. I'm considering buying a MintyBoost, but am wondering if it would be any better?

At home I have a (supposedly) nice MAHA 8 cell charger. For camping I have a PowerFilm solar charger. I don't know how to tell if either of them are really charging the batteries all the way.

By my calculations, a pair of Energizers should provide 2 x 2500 mAh x 1.2 V = 6000 mWh. My Droid X battery is 1500 mAh x 3.7 V = 5550 mWh. So it should be a close match, but wince I'm only getting about need three pairs of AAs to charge my Droid, I'm estimating only 30% efficiency. The cheap Amazon charger gets quite warm to hold, but now I'm understanding that the MintyBoost will too. I built a cable where I could measure the current to the phone, and with fresh cells it starts out at almost a full amp! (Even though the charger says "max 5V 500mA).

So everybody's advice and experience, please. Would a MintyBoost work significantly better than what I have now?