rruff
Explorer
That is deceptive as hell. Give me Watt-Hours!!!!
Help a confused guy put a power bank together (on a shoestring budget)?
- Thread starter Clawhammer
- Start date
That is deceptive as hell. Give me Watt-Hours!!!!
I have fallen for this... recently too...
Anyways, this probably is not helping with the OP’s confusion.
OP, how “shoestring” are we talking about?
rruff
Explorer
List your devices, how much power they draw (watts), and how long they will be on per day, times number of days. Add them up.
Your laptop won't use 100W unless you are doing heavy processing. Nominally 20W or so I'd guess with charging inefficiencies. Does your partner have a laptop as well?
A quick search tells me that a smartphone consumes 3W max. But my wife's higher end phone has a 12 W-hr battery and she can use it all day on a charge. Again this is not heavy processing. And you have to only plug them into charge... don't leave them plugged in.
Are you lighting up the outdoors, or just your camper?
I'm going to make a WAG, just to show the process.
Laptop 1: 20W, 2hrs/day= 40 W-hrs/day
Laptop 2: 20W, 1hr/day,= 20 W-hrs/day
Cell phones: 2x 12 W-hrs/day = 24 W-hrs/day.
Lights: 6x5W, 6hrs/day= 180 W-hrs/day.
Total= 264 W-hrs/day. 1,848 W-hrs/week. Mostly lights. But you *could* use propane torches for outdoor lighting. Or maybe you can get by with less?
It looks like the convenient portable power stations cost ~$1/W-hr. If you use propane torches, and spend $260 on a power station:
Amazon.com: iRozce 300W Portable Power Station, 296Wh Solar Generators with 80000mAh Lithium Battery, CPAP Backup Power Supply with 110V Pure Sine Wave AC Outlet, QC 3.0& Type C, Flashlight for RV, Emergency: Home Improvement
Amazon.com: iRozce 300W Portable Power Station, 296Wh Solar Generators with 80000mAh Lithium Battery, CPAP Backup Power Supply with 110V Pure Sine Wave AC Outlet, QC 3.0& Type C, Flashlight for RV, Emergency: Home Improvement
www.amazon.com
and another $140 on a folding solar panel:
Amazon.com : DOKIO 100W Portable Foldable Solar Panel Kit Lightweight(6lb, 29x21inch) Monocrystalline(HIGH-Efficiency) with Controller (2 USB Ports) to Charge 12v Batteries (Vented AGM Gel) RV Camper Boat Pump : Garden & Outdoor
Amazon.com : DOKIO 100W Portable Foldable Solar Panel Kit Lightweight(6lb, 29x21inch) Monocrystalline(HIGH-Efficiency) with Controller (2 USB Ports) to Charge 12v Batteries (Vented AGM Gel) RV Camper Boat Pump : Garden & Outdoor
www.amazon.com
...I think you'll be in pretty good shape.
rruff
Explorer
It is in fact *not* an energy unit. W-hr is energy.... or J (which is a W-sec), or any other permutation of power x time.
Clawhammer
Adventurer
So, I was given a solar panel for Christmas. It's your basic 120V panel, mounted in an aluminum frame, and It came with a controller for charging a battery. That's awesome, but I'm still really baffled as to what size battery to buy. I'm thinking of something like this battery on Amazon but then am confused as to what sort of fuse block? outlet panel? to use to plug devices up (assuming I use DC lights and charges and whatnot). Obviously, I'm learning as I go here, I don't understand about half of what I've been reading... Going with an invertor seems simpler, even if it is less efficient. Thoughts?
skyfree
Active member
A 35 ah AGM battery is usable for about half of that, maybe 18 ah. That's not much. Look at the depth of discharge chart vs lifetime. When you discharge AGM's all the way the lifetime is very short.
What do you need to run? I have a 200ah dual 6v flooded cell battery bank that I charge with a 150w panel. You could go much higher with that much solar. I would say a 50ah lithium or 100ah AGM would be ideal. Lithium is expensive and light. AGM is cheap and very heavy. If you care more about money than weight and portability, get an AGM battery. For lithium, these Expert Power batteries seem to be a good deal right now at $449. This battery will fit in this box and leave room for some other things you may need like a dc-dc charger.
BTW, the controllers that come with those panels are often really bad. I got one that came with a 50w foldable panel and tested the voltage at over 15v, which is no bueno for charging anything. Test it in sunlight. I got one of these for $20 which has a configurable charging voltage for whatever type of battery you get.
An inverter is only to run 120v things. Get one if you need it, but DC lights will not need that. Charging "devices" via USB? Cigarette outlet? Just get a 12v to USB / cigarette like this.
Fuses = Yes for anything you are connecting outside of your battery box if you want to avoid electrical fires. The easiest way is to get automotive inline fuse holders and fuses like these. Run appropriate fuses for whatever gauge wire you are using. You only need to fuse the positive part of the circuit.
Most people want to charge their battery(s) off the alternator of the vehicle and only use solar when they are stationary for some amount of time. These dc-dc chargers are good for that. Fuse that one and use appropriate wire, connected to your vehicle battery. You will have to run another wire to a circuit that comes on only when the vehicle is running.
I built a nice battery box with all of the above which runs my fridge, lights, fan, and USB outlets. When I get around to it I'll do a detailed posting here.
hour
Observer
Here's a pretty cheap and certainly stupid simple way to do everything you're talking about. I do the same stuff with my DIY portable packs. Macbook pro, phones, lights, bluetooth speaker.
1 x panel mount cigarette socket (may as well get something decent, $10-20, with the high end being Blue Sea's offering)
You could use a more robust connection but this allows you to help some festival friend who assuredly doesn't have anderson powerpole connectors on his Dell laptop car charger
1 x USB-C PD & QC3.0 Combo 12v charger ($20-40, 30-65w+ PD output)
My 2019 16" MBP does fine with 45W despite shipping with an 87w adapter, even compiling code for work and stuff. If I bump down the brightness a notch or two I'll actually start charging versus just sustaining
So right there you can charge your laptop and phone. If you want to charge multiple phones just plug them in to your macbook if you have a dock, or buy a couple USB-C to microUSB and lightning cables. The latter with USB-C to [x] cables is pretty clean and I enjoy it a lot.
Anyway, bore a hole in a tool box, ammo can, whatever you choose - and put the cigarette socket in it.
For lights... if you find 12v ones that have a cigarette lighter end you can obviously just plug them in. If you want to charge your macbook and phone(s) AND run lights, a couple bucks will get you a ciggy Y splitter.
If you find lights that connect via barrel plug - what I would personally seek out - usually/always 2.1x5.5mm plug size (and can often be chained together), a couple bucks will get you a pack of ten 2.1x5.5mm panel mount barrel jacks with rubber dust covers. These can be found with leads already attached. You can also find ones with screw terminals on the back for attaching your own leads, or you can solder. Pop one of those in the side of your box.
We're at like ~$35-60 assuming you have a spare toolbox or grab one cheap, which should be no problem anywhere.
~$100 will get you an off the shelf LiFePO4 20ah 12v/240+ watt hour battery (check ebay) with built in protection and cell balancing + terminals that are easy to connect to. You can also bargain hunt and find them cheaper, usually in a generic blue heat shrink wrap. Just read the reviews if you do that.
Connect everything up and you have a ~$150ish power pack that'll last an extremely long time. Way more cycles than jackery/similar and with a safer chemistry. An easy decade+ of service and no chance of catching the festi field on fire.
For charging you could get by with as little as $20 in to a10 amp Renogy Wanderer solar charge controller. Some MPPT with adjustable current (so you won't overload your power supply) that supports LiFePO4. You could spend more if you wanted and get a Victron but eh.
Mount the charge controller on the wall of your tool box / whatever and maybe drill some holes behind it for good measure w/ air flow. Or drill another circle like you did for the cig socket and pop in some louvered vents to minimize water infiltration. Those are cheap on Amazon and I've used them plenty.
Now the last piece of the puzzle is charging input. I'd just add another 2.1x5.5mm jack as mentioned above re:lights and label it SOLAR INPUT. Wire that to the input on the Renogy.
All of the folding panels I've bought have used 2.1x5.5mm by default, even my 100w non-suitcase style. Plug that in and you're now charging via solar. But what if you want to charge from your car while driving?
Here's the great hack for that.
1) When you're driving, plug the same USB-C PD & QC3.0 Combo 12v charger in to your car's cigarette socket.
2) Buy the 20v version of this for $6 and plug it in to the USB-C port
3) Plug the other end in to your SOLAR INPUT
What happens is that $6 cable does the usb power delivery handshake and makes the charger give you 20v. Your Renogy or whatever charge controller thinks you've connected a solar panel and does its thing. It'll output the max wattage of whatever car charger you chose, so... 30w, 45w, 65w, whatever. You can also charge it at 87w from your macbook power supply at home.
You're in for like $175ish-$200 including some odds and ends like inline fuse holders and maybe a DC extension wire if you want or need it. It'll poop on a jackery 240 and the only thing you're missing is a likely-to-be-useless inverter. You can pick up a Besttek pure sine wave inverter for pretty cheap if you feel the need. 10 minute assembly time and some useful knowledge gained.
1 x panel mount cigarette socket (may as well get something decent, $10-20, with the high end being Blue Sea's offering)
You could use a more robust connection but this allows you to help some festival friend who assuredly doesn't have anderson powerpole connectors on his Dell laptop car charger
1 x USB-C PD & QC3.0 Combo 12v charger ($20-40, 30-65w+ PD output)
My 2019 16" MBP does fine with 45W despite shipping with an 87w adapter, even compiling code for work and stuff. If I bump down the brightness a notch or two I'll actually start charging versus just sustaining
So right there you can charge your laptop and phone. If you want to charge multiple phones just plug them in to your macbook if you have a dock, or buy a couple USB-C to microUSB and lightning cables. The latter with USB-C to [x] cables is pretty clean and I enjoy it a lot.
Anyway, bore a hole in a tool box, ammo can, whatever you choose - and put the cigarette socket in it.
For lights... if you find 12v ones that have a cigarette lighter end you can obviously just plug them in. If you want to charge your macbook and phone(s) AND run lights, a couple bucks will get you a ciggy Y splitter.
If you find lights that connect via barrel plug - what I would personally seek out - usually/always 2.1x5.5mm plug size (and can often be chained together), a couple bucks will get you a pack of ten 2.1x5.5mm panel mount barrel jacks with rubber dust covers. These can be found with leads already attached. You can also find ones with screw terminals on the back for attaching your own leads, or you can solder. Pop one of those in the side of your box.
We're at like ~$35-60 assuming you have a spare toolbox or grab one cheap, which should be no problem anywhere.
~$100 will get you an off the shelf LiFePO4 20ah 12v/240+ watt hour battery (check ebay) with built in protection and cell balancing + terminals that are easy to connect to. You can also bargain hunt and find them cheaper, usually in a generic blue heat shrink wrap. Just read the reviews if you do that.
Connect everything up and you have a ~$150ish power pack that'll last an extremely long time. Way more cycles than jackery/similar and with a safer chemistry. An easy decade+ of service and no chance of catching the festi field on fire.
For charging you could get by with as little as $20 in to a
Mount the charge controller on the wall of your tool box / whatever and maybe drill some holes behind it for good measure w/ air flow. Or drill another circle like you did for the cig socket and pop in some louvered vents to minimize water infiltration. Those are cheap on Amazon and I've used them plenty.
Now the last piece of the puzzle is charging input. I'd just add another 2.1x5.5mm jack as mentioned above re:lights and label it SOLAR INPUT. Wire that to the input on the Renogy.
All of the folding panels I've bought have used 2.1x5.5mm by default, even my 100w non-suitcase style. Plug that in and you're now charging via solar. But what if you want to charge from your car while driving?
Here's the great hack for that.
1) When you're driving, plug the same USB-C PD & QC3.0 Combo 12v charger in to your car's cigarette socket.
2) Buy the 20v version of this for $6 and plug it in to the USB-C port
3) Plug the other end in to your SOLAR INPUT
What happens is that $6 cable does the usb power delivery handshake and makes the charger give you 20v. Your Renogy or whatever charge controller thinks you've connected a solar panel and does its thing. It'll output the max wattage of whatever car charger you chose, so... 30w, 45w, 65w, whatever. You can also charge it at 87w from your macbook power supply at home.
You're in for like $175ish-$200 including some odds and ends like inline fuse holders and maybe a DC extension wire if you want or need it. It'll poop on a jackery 240 and the only thing you're missing is a likely-to-be-useless inverter. You can pick up a Besttek pure sine wave inverter for pretty cheap if you feel the need. 10 minute assembly time and some useful knowledge gained.
Last edited:
broncobowsher
Adventurer
So a 12V battery, 15 Ah of capacity is needed. A nice AGM battery commonly has 100 Ah capacity. Plenty of reserve. (sorry, had to drop down to Ah because that is how 12V batteries are rated) So 4 golf cart batteries is WAY overkill.
I would look at what size battery the Taco takes and look up an AGM of the same size. Check the Ah rating. Also remember that you want to avoid draining below 50% for a long life.
Now is also the time to think ahead. Ever plan on adding a fridge? A little extra capacity might be needed.
Solar is a nice addition, but that too takes planning. A little 15W panel won't keep up. The rated output is peak, aimed at the sun, in the middle of the day, in the summer, while kept cool, and a handful more of disqualifiers. A 30-50W panel would be a better match. But this isn't even a must. Multi-day use, real good idea. A 1-day use, I would recomend to just skip for now. Use the vehicle driving home and the battery tied in to top off the charge.
And don't store the battery at a low charge. Even if that means going home and putting it on a battery tender.
Unfortunately that does not work. The battery will try to sink all the watts it can get, the charger will trigger its overcurrent protection and switch off. If your solar controller can limit the charge current you‘re ok, but then your solar charging is limited to the same current unless you want to be changing the settings all the time.
RDinNHand AZ
Active member
Bit’O’Hijack here but related I hope. I built a LiFePO4 650 Wh battery box (53Ah@+-13 volts). I want to charge form the 15 amp cigar lighter socket. Can I just run a power cable from that into my solar controller? It's a Renogy New Edition Voyager 10A PWM Waterproof Solar Charge Controller, 10 Amp? Thanks
hour
Observer
Yes the entire premise of this was based on using a programmable MPPT, and it works great.
In your post you specifically mention the Renogy Wanderer, and I don't believe it's possible to achieve what you're proposing with that controller. Happy to be corrected if I missed something.
hour
Observer
Good catch, wanderer is PWM. I mistakenly bought that probably around the time of that post before I learned they're no good for feeding directly from a power supply. As to whether you can adjust the current... ?♂️ mine will likely sit on the shelf for eternity. Sorry bout that. Victron or bust anyway..