# Need help with solar panel and battery bank design

#### TrevorMcNeill

Joined Mar 31, 2017
5
So I am a bit of a novice still when it comes to this but I know enough to get rough ideas. Currently I am designing a foldable and semi-flexible solar panel and a battery bank with 16 18650 3.7 3000 mAh batteries. These are the cells I plan on using

http://m.ebay.com/itm/181803913088?_trksid=p2385738.m2548.l4275&_mwBanner=1&varId=480750586068

The plan is to have 12 of them running in series with a 1N914 blocking diode on the positive wire giving me an max output of 31.2W, 5.4V, and 5.8A . The problem is the amperage is to high, The batteries have a max change current of 4A.

As for the battery bank it's 16x 18650 3.6V 3000mAh in parallel giving me 48000mAh. Here is the controller .

http://m.ebay.com/itm/Dual-USB-5V-1...er-PCB-For-Phone-DIY-/171659961777?nav=SEARCH

And help or suggestions are appreciated.

#### Dodgydave

Joined Jun 22, 2012
10,583
Well one thing is it wont work with a 1N914 diode, as it only takes 150mA, can you draw the layout of your batteries (series parallel) it's easier to solve!

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#### TrevorMcNeill

Joined Mar 31, 2017
5

#### Alec_t

Joined Sep 17, 2013
13,219
max output of 31.2W, 5.4V, and 5.8A . The problem is the amperage is too high, The batteries have a max charge current of 4A.
If you have 16 batteries in parallel they will share the available current, so each battery would get far less than its maximum 4A.
But how will you ensure that the batteries don't get over-charged (and hence liable to explode or catch fire)?

#### TrevorMcNeill

Joined Mar 31, 2017
5
Well I haven't looked to see but the booster has a charge percentage so I would assume it would cut power after its at 100%. What sucks is its only rated to 1A which would take forever for it to charge, I may see if I can just find a good schematic and do one myself. If anyone knows of a better controller for that please let me know.