DIY solar power bank 5V 230Wh - Page 3

Daox · 08-13-19, 11:52 AM

I got the handle printed. The handle is printed a fair amount more dense to take the load it will see.

I also got it installed. It was a bit tricky getting the screws all the way in there as the main housing is pretty long, but I managed. Thankfully the inside is big enough to get the screwdriver handle into.

pinballlooking · 08-13-19, 12:46 PM

It is looking good so far.

Daox · 08-13-19, 10:11 PM

Thanks! Its been a very fun project thus far.

Daox · 08-14-19, 08:13 AM

I ended up having to reprint the bottom piece. The two end holes were 1/16" off and it just didn't line up nicely. Cut twice measure once, right?

I'm still working on that. Anyway, it now assembles nicely and things line up great. It even looks pretty good IMO.

I put some rubber D-shaped weather stripping in the bottom piece to cushion the battery pack. Its darn near perfect. It starts mashing the rubber with a ~1/8" gap.

With the handle attached, it was time to slide in the battery pack. It fits with a little resistance. There is a bit of a gap side to side, but not bad.

Next up I put the wires on the batteries. I ended up having to drill out the holes that go from the battery compartment to the electronics compartment. I apparently didn't look up what gauge wire to use to handle the possible 10A draw. I think I settled on 14 gauge.

Here we have the unit mostly assembled and ready for electronics.

Daox · 08-15-19, 07:20 AM

What would you guys recommend for fusing on this circuit?

Daox · 08-16-19, 12:01 PM

I got the charge controller yesterday. This was a nice surprise as it wasn't due for another week or two.

I got a little bracket printed up for it.

And got it clipped in place.

I haven't hooked it up yet. I am still wondering what, if anything, I should put a fuse on.

Daox · 08-19-19, 11:00 AM

While waiting on the other electronic bits, I ordered and received mysolar panel. It measures about 18X14".

It is a 20W 12V panel sold by Newpowa. Operating voltage is 17.2V and 1.16A. This is what I will set the 'MPPT' controller to. It will maintain the 17.2V at whatever amperage the panel can supply.

I was concerned that achieving the 17.2V on a cloudy day was going to be an issue. The whole reason I went with the 12V panel was so I could get some charging done on cloudy days as I am only charging a 3.3V battery. But, my worries were quickly dismissed as I tested the open circuit voltage on the panel on an overcast day. I edited the brightness of this picture to accurately show what kind of light the panel was seeing. I hooked up the wire leads to the voltmeter and it was showing a nice 19.8V! So, even on cloudy days it should have no problem hitting the 17.2V. How much amperage we can get is obviously going to be low, but at least it will be something.

This is roughly how the panel will bit sitting for now. I may 3d print some sort of mount to hold it at a bit of an angle or something. We will see how it does.

Daox · 08-22-19, 05:04 PM

The DC-DC converters are getting close to being here. I hope they get here before the weekend so I can get this thing up and running.

I am still wondering if you guys have any thoughts on putting fuses into this setup?

NiHaoMike · 08-22-19, 07:35 PM

Just one fuse at the battery is all you need for your setup. If it's still 15W, a 7.5A or 10A fuse will give plenty of margin.

Daox · 08-23-19, 12:19 PM

Thanks Mike. The max draw will be a bit over 30w (15W per USB plug) plus the converter inefficiency.

08-13-19, 11:52 AM	#21
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	I got the handle printed. The handle is printed a fair amount more dense to take the load it will see. I also got it installed. It was a bit tricky getting the screws all the way in there as the main housing is pretty long, but I managed. Thankfully the inside is big enough to get the screwdriver handle into. Attached Thumbnails __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

08-13-19, 12:46 PM	#22
pinballlooking Super Moderator Join Date: Jun 2013 Location: SC Posts: 2,923 Thanks: 172 Thanked 564 Times in 463 Posts	It is looking good so far. __________________ Current project Aquaponics system , Passive Solar Greenhouse build To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. Solar Install 12.5 Kwh- To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. Mini Split installs - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. EV Chevy Volt - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

08-13-19, 10:11 PM	#23
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	Thanks! Its been a very fun project thus far. __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

08-14-19, 08:13 AM	#24
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	I ended up having to reprint the bottom piece. The two end holes were 1/16" off and it just didn't line up nicely. Cut twice measure once, right? I'm still working on that. Anyway, it now assembles nicely and things line up great. It even looks pretty good IMO. I put some rubber D-shaped weather stripping in the bottom piece to cushion the battery pack. Its darn near perfect. It starts mashing the rubber with a ~1/8" gap. With the handle attached, it was time to slide in the battery pack. It fits with a little resistance. There is a bit of a gap side to side, but not bad. Next up I put the wires on the batteries. I ended up having to drill out the holes that go from the battery compartment to the electronics compartment. I apparently didn't look up what gauge wire to use to handle the possible 10A draw. I think I settled on 14 gauge. Here we have the unit mostly assembled and ready for electronics. Attached Thumbnails __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

08-15-19, 07:20 AM	#25
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	What would you guys recommend for fusing on this circuit? __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

08-16-19, 12:01 PM	#26
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	I got the charge controller yesterday. This was a nice surprise as it wasn't due for another week or two. I got a little bracket printed up for it. And got it clipped in place. I haven't hooked it up yet. I am still wondering what, if anything, I should put a fuse on. Attached Thumbnails __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

08-19-19, 11:00 AM	#27
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	While waiting on the other electronic bits, I ordered and received mysolar panel. It measures about 18X14". It is a 20W 12V panel sold by Newpowa. Operating voltage is 17.2V and 1.16A. This is what I will set the 'MPPT' controller to. It will maintain the 17.2V at whatever amperage the panel can supply. I was concerned that achieving the 17.2V on a cloudy day was going to be an issue. The whole reason I went with the 12V panel was so I could get some charging done on cloudy days as I am only charging a 3.3V battery. But, my worries were quickly dismissed as I tested the open circuit voltage on the panel on an overcast day. I edited the brightness of this picture to accurately show what kind of light the panel was seeing. I hooked up the wire leads to the voltmeter and it was showing a nice 19.8V! So, even on cloudy days it should have no problem hitting the 17.2V. How much amperage we can get is obviously going to be low, but at least it will be something. This is roughly how the panel will bit sitting for now. I may 3d print some sort of mount to hold it at a bit of an angle or something. We will see how it does. Attached Thumbnails __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

08-22-19, 05:04 PM	#28
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	The DC-DC converters are getting close to being here. I hope they get here before the weekend so I can get this thing up and running. I am still wondering if you guys have any thoughts on putting fuses into this setup? __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

08-22-19, 07:35 PM	#29
NiHaoMike Supreme EcoRenovator Join Date: Oct 2008 Location: Austin, TX Posts: 1,154 Thanks: 14 Thanked 257 Times in 241 Posts	Just one fuse at the battery is all you need for your setup. If it's still 15W, a 7.5A or 10A fuse will give plenty of margin. __________________ To my surprise, shortly after Naomi Wu gave me a bit of fame for making good use of solar power, Allie Moore got really jealous of her...

08-23-19, 12:19 PM	#30
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	Thanks Mike. The max draw will be a bit over 30w (15W per USB plug) plus the converter inefficiency. __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. Last edited by Daox; 08-24-19 at 09:00 AM..