Oudie Supplemental Power Pack

On Wednesday, September 27, 2017 at 2:54:49 PM UTC-7, JS wrote:
I'd think the RigRunner 4004-USB would be best for the job. 4x fused 12v outlets plus two USB ports, in a shielded case.
Jim
https://powerwerx.com/west-mountain-...unner-4004-usb

I wish they and other manufacturers would spec the USB power output. These could supply 0.5A up to 3.0A total or more and still be considered meeting a USB standard. I've seen some awful low actual power delivered from cheap USB adapters, I expect better than average quality from RigRunner but wish vendors would just clarify with specs.

And it's a reminder that modern small devices can draw significant power. As an example an iPhone 7 Plus has a 2.68 Ah battery at 3.8 V. Just charging that battery from flat, and assuming 80% charge efficiency will suck around 1 Ah of charge from a glider 12V battery. On top of whatever it takes to run the device at high screen brightness. Which reminds me I want to remeasure power use and charging of a few modern devices..... its pretty amazing the compact compute and power capacity we carry around nowadays.

I've got to replace the (not cheap/no brand) power supply in my truck, which struggles to deal with a flat iPhone 7 Plus.

On Wednesday, September 27, 2017 at 3:43:56 PM UTC-7, Darryl Ramm wrote:
And it's a reminder that modern small devices can draw significant power. As
an example an iPhone 7 Plus has a 2.68 Ah battery at 3.8 V. Just charging
that battery from flat, and assuming 80% charge efficiency will suck around
1 Ah of charge from a glider 12V battery. On top of whatever it takes to run
the device at high screen brightness. Which reminds me I want to remeasure
power use and charging of a few modern devices..... its pretty amazing the
compact compute and power capacity we carry around nowadays.

Yep... My panel pulls around 1.7 amps sitting on the ground so assuming a couple of brand new K2 10Ah batteries I'd get a bit over 11 hours runtime. I was getting a lot less. After discovering one of my new to me, but several years old batteries was pretty much dead, I replaced with a pair of Craggy Aero LiFePO4 batteries. Still struggled to get more than 5 hours until I replaced my master switch with a high quality one.

I might be able to modify one battery compartment in my ASW-27 to take the 15Ah battery, but there's definitely no room on the other side. Would it be bad to run a big and small LiFePO4 in parallel? Let the BMS handle the taking the small battery offline after it's depleted? I also need to look into installing a tail battery since the wiring is all there so just need to find something that will fit.

Getting back on the thread, this is why I now power my iPhone with an external battery. It's easy and cheap insurance to keep my avionics going for the long flights I like to do.

5Z

Tom

Got to keep reminding myself you now fly a ASW27 not the (massive battery carrying) ASH26. Sorry I don't know for for sure with running those batteries in parallel, I'd check with Richard. I've always liked to run 2 x large batteries, 2 x 10Ah in the DG-303 or 2 x 17Ah in the ASH26E. I like having a roughly known clean reserve to switch to. With 10Ah/15Ah batteries I'd just run them by themselves, but thats personal preference not based on other reasons.

Darryl



On Wednesday, September 27, 2017 at 4:35:43 PM UTC-7, wrote:
On Wednesday, September 27, 2017 at 3:43:56 PM UTC-7, Darryl Ramm wrote:
And it's a reminder that modern small devices can draw significant power. As
an example an iPhone 7 Plus has a 2.68 Ah battery at 3.8 V. Just charging
that battery from flat, and assuming 80% charge efficiency will suck around
1 Ah of charge from a glider 12V battery. On top of whatever it takes to run
the device at high screen brightness. Which reminds me I want to remeasure
power use and charging of a few modern devices..... its pretty amazing the
compact compute and power capacity we carry around nowadays.

Yep... My panel pulls around 1.7 amps sitting on the ground so assuming a couple of brand new K2 10Ah batteries I'd get a bit over 11 hours runtime.. I was getting a lot less. After discovering one of my new to me, but several years old batteries was pretty much dead, I replaced with a pair of Craggy Aero LiFePO4 batteries. Still struggled to get more than 5 hours until I replaced my master switch with a high quality one.

I might be able to modify one battery compartment in my ASW-27 to take the 15Ah battery, but there's definitely no room on the other side. Would it be bad to run a big and small LiFePO4 in parallel? Let the BMS handle the taking the small battery offline after it's depleted? I also need to look into installing a tail battery since the wiring is all there so just need to find something that will fit.

Getting back on the thread, this is why I now power my iPhone with an external battery. It's easy and cheap insurance to keep my avionics going for the long flights I like to do.

5Z

Tom,

I used to run three SLA batteries in my LAK-17a.Â* To do that, I used TWO
SPDT switches and turned a fresh battery on before turning the depleted
battery off.Â* The charging current to the depleted battery was
insignificant during switching and was never a problem.Â* After switching
to LiFePO4 batteries, I eliminated the tail battery (replaced it with
lead ingots (in an aluminum box) and called it good.Â* Frankly, I never
had to switch batteries again after installing the lithium batteries so
I alternated batteries between flights.

But to your point - the tail battery compartment in your '27 ought to be
sized for a 9 or 10 Ah SLA battery and there are LiFePO4 batteries made
to the exact same size.Â* Of course, the weight is significantly less.

Dan

On 9/27/2017 5:50 PM, Darryl Ramm wrote:
Tom

Got to keep reminding myself you now fly a ASW27 not the (massive battery carrying) ASH26. Sorry I don't know for for sure with running those batteries in parallel, I'd check with Richard. I've always liked to run 2 x large batteries, 2 x 10Ah in the DG-303 or 2 x 17Ah in the ASH26E. I like having a roughly known clean reserve to switch to. With 10Ah/15Ah batteries I'd just run them by themselves, but thats personal preference not based on other reasons.

Darryl



On Wednesday, September 27, 2017 at 4:35:43 PM UTC-7, wrote:
On Wednesday, September 27, 2017 at 3:43:56 PM UTC-7, Darryl Ramm wrote:
And it's a reminder that modern small devices can draw significant power. As
an example an iPhone 7 Plus has a 2.68 Ah battery at 3.8 V. Just charging
that battery from flat, and assuming 80% charge efficiency will suck around
1 Ah of charge from a glider 12V battery. On top of whatever it takes to run
the device at high screen brightness. Which reminds me I want to remeasure
power use and charging of a few modern devices..... its pretty amazing the
compact compute and power capacity we carry around nowadays.
Yep... My panel pulls around 1.7 amps sitting on the ground so assuming a couple of brand new K2 10Ah batteries I'd get a bit over 11 hours runtime. I was getting a lot less. After discovering one of my new to me, but several years old batteries was pretty much dead, I replaced with a pair of Craggy Aero LiFePO4 batteries. Still struggled to get more than 5 hours until I replaced my master switch with a high quality one.

I might be able to modify one battery compartment in my ASW-27 to take the 15Ah battery, but there's definitely no room on the other side. Would it be bad to run a big and small LiFePO4 in parallel? Let the BMS handle the taking the small battery offline after it's depleted? I also need to look into installing a tail battery since the wiring is all there so just need to find something that will fit.

Getting back on the thread, this is why I now power my iPhone with an external battery. It's easy and cheap insurance to keep my avionics going for the long flights I like to do.

5Z

--
Dan, 5J