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Trying to build Solar Power Bank

Posted: Sun Jan 13, 2019 8:59 am
by FlashPan
Hello all,

I'm thinking of building a solar power bank/wall mainly to power usb lighting, AA/AAA battery chargers, USB battery banks, baofeng radio charger etc nothing major like a tv or fridge. Buying some kit and using existing kit. Unless all prepackaged this subject always gets me somewhat lost. So would appreciate some guidance/advice here please :)

I own at home a APC Smart UPS 3000 for my home network and uses this set of batteries I could remove:

https://www.ebay.co.uk/itm/RBC12-Batter ... ctupt=true

I have also seen this setup on ebay I think I could use to charge the batteries:

https://www.ebay.co.uk/itm/20w-Mono-Sol ... :rk:6:pf:0

...and then this I think I would use to run/connect appliances to:

https://www.ebay.co.uk/itm/1500-3000W-C ... 0005.m1851

Do I have this setup correct:

Connect the batteries and solar panel to the blue box in the 2nd listing (left and centre connection) then connect the invertor to the blue box (right connector) and then connect the bits I need to power from that?

I'm not looking for a portable device but something that is easily stowable, so very large solar panels (or many) or not so much of an option I can run with.

I've actually just thought, could I somehow connect the solar panels direct to my UPS? But then that leads me to think too much power could be lost just running/managing the UPS?

Thanks in advance for your thoughts and comments.

Cheers

Re: Trying to build Solar Power Bank

Posted: Sun Jan 13, 2019 9:38 am
by Yorkshire Andy
Ill try.......

the 8x 7.2ah cells only give you 57.6 ah not a lot when you concidder you should only take them to 50%Depth of discharge (DOD) so 28ah usable


if you have them make use of them id budget in the future for a dedicated leisure battery ( intended for cyclic use)


as for the solar panel GO BIG! as a minimum id look at 60w ( i started my shed project on 30w and it really struggled in winter)

the 30w unit i got was expandable to 60w (one of the reasons i got it )

https://www.photonicuniverse.com/en/cat ... CYQAvD_BwE


looks like they have a new charge controller with a built in USB..

which is the brains of what your building it controls charge and discharge and cuts off when the voltage drops to the area you risk damaging your battery via the load outputs there are 6x terminals on it 2 for the battery +& - 2 for the solar + & - and 2 for the load + & - this load is where you can add your items pulling upto 5a it also has short circuit protection and overload protection

or more portable solution

https://www.amazon.co.uk/d/Car-Electron ... B013VVUQM6




onto appliences Inverters are ok BUT they knock the shit out the battery at 1000w you will be pullng close to 40a so 28ah of power you will get less than 15 mins use,,,,,, (inverters should be connected to the battery directly)

Id look at 12v chargers much more efficent than stepping up to mains then back to 5v or so....

eg

https://www.miniinthebox.com/en/p/baofe ... 40QAvD_BwE


and for most other stuff

https://www.lightinthebox.com/en/p/12v- ... MIQAvD_BwE


you can get laptop 12v to 18v step up units too must caravaners have dropped them for a usb chargeable tablets





viewtopic.php?f=38&t=12046


viewtopic.php?f=38&t=11070

viewtopic.php?f=38&t=8297

Re: Trying to build Solar Power Bank

Posted: Mon Jan 14, 2019 8:47 am
by FlashPan
Hi and thanks for the info. I guess yes I should have thought before that UPS batteries are not designed to be charged/discharged frequently. I'll start looking at deep cycle ones. Also thanks for the other info. I still got some reading and understanding to do.

Thanks

Steve

Re: Trying to build Solar Power Bank

Posted: Mon Jan 14, 2019 8:54 am
by Brambles