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modified car power adapter still not giving enough power

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timropp
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Default modified car power adapter still not giving enough power

I bought a Griffin Powerjolt Dual Micro adapter (http://www.amazon.com/gp/product/B00...00_i00_details). It supposedly can do 1A on each port. I modded it as the commenters on Amazon suggested (open up, solder the middle pins on each side together so that it's recognized as an AC charger rather than USB).

Both my Flyer (Leedroid HC rom) and Evo 4G see it correctly as an AC charger. However, monitoring the current via Elixir says it's not getting near 1A. For example, the flyer was showing somewhere between -500ma and -700ma while unplugged (GPS on, wifi tethering). When I plugged it into this charger, it was showing around -50ma. So it's getting only around 600ma of juice, not 1000ma.

Testing my Evo on the charger showed the same.

Using an actual HTC AC charger (old one, from my TouchPro2 days, but rated for 5V 1A) both devices indicate they're getting somewhere around 900ma, much more like I'd expect.

So is this charger just crap? Or is that normal for a car 1A charger? I'm debating getting something else - ideally one of the chargers that claims to have both a 2.1A port and a 1A port, since I want to run both the flyer and evo (for tethering) in the car. Got suggestions on any that are good? Small would be best since a big charger blocks my cupholder
 
DigitalMD
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You'll be best off getting a small 12 /120 inverter. The magic is in the HTC charging cord connector not the power supply. Just use the inverter with the HTC wall wart. It produces 9v at 1.2 A. Since the Flyer has two batteries, it really needs more than 5v
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timropp
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That just seems like such a ridiculous way to do it - 12V in car, converted to 120v AC, then BACK to DC at 9V...

I tried another USB adapter that I had lying around, a really really cheapo one that claimed to be 1A. Well, my phone shows it's getting around 900ma from it. So not too bad, and certainly better than the name brand that I modified. So looks like I'm back to the hunt... either a dual-usb 1A each adapter, or better yet, a 2.1A/1A dual adapter that can actually output that much.

But still, even the modded one isn't too bad. at only 50ma net drain, that flyer battery would last longer in the car than I will
 
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Originally Posted by DigitalMD View Post
You'll be best off getting a small 12 /120 inverter. The magic is in the HTC charging cord connector not the power supply. Just use the inverter with the HTC wall wart. It produces 9v at 1.2 A. Since the Flyer has two batteries, it really needs more than 5v
I think there is easier way. Griffin 2A car charger has chip inside, it can give up to 20 or 30V and 3A! Voltage is regulated by changing only one resistor. I have datasheet somewhwere, but you can google. Datasheet will explain what resistor and wat value is needed for 9V.
So changing resistor should be enough, but I am not shure 100% because I do not know if Flyers original charger uses specific pins or the same usb pins for charging

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timropp
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Well, you don't really want to change voltage I don't think. I know the official charger does 9V over the same pins as the usual microUSB 5 pins, but I don't know for sure if the flyer has to do anything special to know 9V is coming. Or if the pinout is different.

So for now, I'm planning to just get an ipad-type 2A 5V charger, mod it (since the ipad doesn't use standard methods of knowing the charger can do more than 500ma), and see how that works.

I'm not terribly concerned about CHARGING the flyer in teh car. I just don't want to lose too much battery while on a long drive. So even a true 1A charger would be fine - that's more than the flyer draws. I just thikn the charger I got isn't actually doing what it says.
 
linuxis
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Well, you don't really want to change voltage I don't think. I know the official charger does 9V over the same pins as the usual microUSB 5 pins, but I don't know for sure if the flyer has to do anything special to know 9V is coming. Or if the pinout is different.

So for now, I'm planning to just get an ipad-type 2A 5V charger, mod it (since the ipad doesn't use standard methods of knowing the charger can do more than 500ma), and see how that works.

I'm not terribly concerned about CHARGING the flyer in teh car. I just don't want to lose too much battery while on a long drive. So even a true 1A charger would be fine - that's more than the flyer draws. I just thikn the charger I got isn't actually doing what it says.
You are not right. It gives up to 3A, but voltage is too low for Flyer. To charge properly Flyer needs 9V voltage and up to 1.2A. If voltage will be only 5v - you never will never get 1A with flyer. Tested various 1 or 2A chargers (even genuine Iphone) with data pins connected. And i also said that griffin circuitry is capable of giving more than 1A. HTC HD2, draws its maximum ~800mA from griffin, so you theory would say that Flyer can draw more than 500mA too but it doesn't so it is due to voltage or special pins.

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timropp
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The flyer does not NEED 9V - it's just faster. Heck, the thing came w/ a USB cable which is only 5V and it will charge, just not as fast.

I've got some REALLY cheap USB car chargers (look like this http://www.aliexpress.com/product-fm...olesalers.html and I got them for like a buck a piece). Sticker says it'll do 1A. On both my Evo and my Flyer, I get around 900-950ma out of it. So yes, the flyer can indeed draw 1A from a charger that can do it.

I think the charger I've got (the one in the original post) is just crappy. I ordered another model (http://www.amazon.com/gp/product/B0056VNVV8) which claims to have a 2A port and a 1A port. I'll try it out, don't expect it to actually do that stock since the ipad is the main device that uses 2A and uses proprietary methods to signal that. Then I'll open it up and short the data pins and see what I get. HOPEFULLY I can pull enough juice from it to keep both the flyer and evo happy.
 
linuxis
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Originally Posted by timropp View Post
The flyer does not NEED 9V - it's just faster. Heck, the thing came w/ a USB cable which is only 5V and it will charge, just not as fast.

I've got some REALLY cheap USB car chargers (look like this http://www.aliexpress.com/product-fm...olesalers.html and I got them for like a buck a piece). Sticker says it'll do 1A. On both my Evo and my Flyer, I get around 900-950ma out of it. So yes, the flyer can indeed draw 1A from a charger that can do it.

I think the charger I've got (the one in the original post) is just crappy. I ordered another model (http://www.amazon.com/gp/product/B0056VNVV8) which claims to have a 2A port and a 1A port. I'll try it out, don't expect it to actually do that stock since the ipad is the main device that uses 2A and uses proprietary methods to signal that. Then I'll open it up and short the data pins and see what I get. HOPEFULLY I can pull enough juice from it to keep both the flyer and evo happy.
Yes, Flyer does not need 9v, but only when charged from usb port. In USB case Flyer identifies power source as usb and do not try to get more than than 500mA. By shortening data pins we make Flyer identify power source as AC, so it thinks that it draws power from charger ( it expects 9V 1.62A) so charging from 5V 2A doesn't work as from 9V source. I have already tried Samsung 2A charger, Griffin car charger 2A, iPhone 1A charger.... (With data pins shortened) Flyer identifies them as AC source but current do not rise more than 500mA and only when power/screen off. When on - I think charging do not work because Battery Monitor Pro shows opposite current flow (discharge).
So:
a) Your charger is not crappy...
b) 5v*2A=10W is less than 9V*1.62A=14.58W

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timropp
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Not sure why you had no luck w/ all those chargers. I've used both the flyer and my evo 4g to test, monitored w/ elixir (showing the ma flow either direction, use or charging), and several adapters both AC and car.

My flyer absolutely could draw 900ma or more out of the cheapo car charger at 5V. That's plenty to keep it charged and even add some charge slowly (about 300ma gain) while using GPS, full bright screen, and tethered over wifi to my phone.

The problem is that is a single USB charger, and my car only has 1 cig lighter port. So I'm looking for a dual-USB charger. I'll post the results of the new one that's on the way.
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stm8
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i used a Griffin USB charger in my car for a while, and it didn't do a bad job. I think it was rated as 2.1 amps. I had to try several USB-to-microUSB cords to find one that was wired for charging, and not just data transfer/trickle charge.

Finally, I gave in and bought the proprietary HTC car-charger from Sprint, and it works great! If I turn on everything I can (mobile data, wifi, gps, screen brightness, nav app, etc) it will keep my EVO View running great and charge the tablet in fairly short order.

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