Sanity check for tiny portable system

[Cosmic Osmo]

I'm thinking of the following and just want to bounce it off the forum for any gotchas or better ideas.

The use case is running LED strips in my garden shed (~25 Wh/day probably), and also being able to take the system down to use it for ham field day (100-200 Wh/day, but mostly concentrated to the time of greatest sun), and if the cascadian subduction earthquake ever hits, to have a backup option that'll allow us to keep things like phones, electric toothbrushes, cordless drill, maybe a laptop usable in a prolonged grid-down (50-100 Wh/day). Also, there's the hobby/tinkering aspect.

Components:

** 70W Newpoa 12v panel ($70)

** Renogy wanderer 10 amp PWM charge controller ($20) - I understand MPPT (eg. Genasun) would be more efficient, but for that price, I could just double the panel, which would provide more power increase than going to MPPT.

** ExpertPower 12v 10 Ah LiFePO4 battery, built-in BMS ($100)

** AIMS power 180 watt pure sine wave inverter ($100) - not strictly necessary because all my planned loads are DC, but might be nice to have around just in case

Any obvious issues with that configuration? Thanks!

[Mike90250]

A 10ah battery is pretty small. A 70w panel can harvest more sun than the 10ah battery can store, so that's a 2nd vote for a larger battery.

I'd suggest your first foray into solar power be with a larger panel or more panels, in the 200w range, and a 100ah of conventional lead acid battery. That's where I suggest investing

[Cosmic Osmo]

A 100 Ah (~60 lb) battery doesn't meet my goal of a portable system, and your recommendation also increases the cost by 2-3x for capability that I believe I don't need.

[SunEagle]

A 10ah battery is pretty small. A 70w panel can harvest more sun than the 10ah battery can store, so that's a 2nd vote for a larger battery.

I'd suggest your first foray into solar power be with a larger panel or more panels, in the 200w range, and a 100ah of conventional lead acid battery. That's where I suggest investing

Heck my Auto Jump Start system has an 18Ah battery and most of my UPS systems have more than 10Ah so that is a very small system

My portable solar/battery includes a 65Ah battery and an 80 watt (I should have used a 100W) folding panel. While my system is not light it can be pulled around using a small hand cart.

[Cosmic Osmo]

Thanks for the input. Would bumping up to a 15 Ah LiFePO4 make this seem like a more balanced system? I really don't want to go with lead for size and weight reasons.

[SunEagle]

Thanks for the input. Would bumping up to a 15 Ah LiFePO4 make this seem like a more balanced system? I really don't want to go with lead for size and weight reasons.

A 15Ah LiFePO4 battery can be charged between a range of 1.25 amps to 3 amps. A 70w panel will probably exceed that 3 amp which could hurt the battery by charging it too fast. Although if you don't point the panel directly at the sun you will get less then the Imp rating of that panel.

Well I also have a 20Ah Lithium battery pack that can be charged from an outlet or my computer through a USB connection and has a flashlight built in. I can easily charge my phone 5 times over with it and it is very small and portable.

So my question is what do you plan on using your portable system for?

[Mike90250]

I'll still maintain that 10ah is small. Even for limited uses. And I think most 10A Li batteries will cost about the same as a 90A deep cycle lead acid battery.


If your mind is made up, good luck, and I'd not bother with the inverter, it's not likely to power a 60W load for more than 15 min
60W @ 12V = 5A That's half the battery capacity and it won't keep that up for long.

This album may give you some ideas (should link to my portable solar monolith)

https://www.facebook.com/burgessms/media_set?set=a.1559540947236&type=3

[Freeesun]

thats a very small battery for $100 i bought a 80ah battery fla at wall mart for around that price. also you can double your solar panel size for fairly cheap, i bought my 150 watt coleman on sale at canadian tire for a little more than what you spent. i produce around 6-10amps with my panel and im not even facing south.

[Mike90250]

thats a very small battery for $100 i bought a 80ah battery fla at wall mart for around that price. also you can double your solar panel size for fairly cheap, i bought my 150 watt coleman on sale at canadian tire for a little more than what you spent. i produce around 6-10amps with my panel and im not even facing south.

Freesun - edit your member profile and add your SIGNATURE LINE with your solar gear. (and everyone else, so you don't have to type it out each time you ask a question)

[Freeesun]

Thank you I actually asked how to do this in a different post.

[Freeesun]

I can’t seem to find signature line?

[bob-n]

Yes, it's tough to find. I just tried and it took me 15 minutes.

Top right, click your user ID and select User Settings.
Then select the tab Account.
Then half way down is small text Edit Post Signature.