Is it possible to patch together a DC system with these random materials? [closed]

Question

I have a small collection of random batteries and solar panels, plus two charge controllers. I am hoping to build a system which can charge devices like phone, tablet, portable power banks, etc. (typically 5v 700mA-2A devices), plus a 12v cooler. The idea is to connect all devices to the battery bank via car lighter sockets; or perhaps a USB hub for devices + lighter socket for the cooler.

Equipment:

• PV1: 40W 2.3A crystalline solar panel (Coleman #51840)

• PV2: 2.5W 167mA amorphous solar panel (Coleman #51802)

• PV3: 5W ?A amorphous solar panel (UniSolar RM1206)

• PV4: 15Vmp, 966 mA Imp.
  Wp=15W Voc=24V Isc=1002mA System Voltage Maximum=50V probably amorphous solar panel (ICP Canada #unknown)

• PV5: Unknown. probably 5V probably amorphous solar panel (data sticker unreadable)

• SC1: 7A ?W 12V solar charge controller (Coleman #51840 - bundled with 40W panel)

• SC2: 30A 450W 12V solar charge controller (Coleman #68032)

• B1: Everstart Maxx 41N battery x2

• B2: Energizer 72-41N battery
• B3: Energizer 108-700N battery
• B4: Yuasa 12V 20Ah battery x2
• B5: Trojan SCS200 deep cycle battery
• B6: Magnacharge 65-1100 battery x2
• B7: Federal battery

I still have some work to do finding specs for the batteries, but hopefully this gives a good enough picture of what I'm working with. Is it possible to build a system from these random parts?

Answer 1

> Is it possible to patch together a DC system with these random materials?

YES

PV1, 2, 4 appear to be close enough to 15V Vmp to work together.
PV3 may be - measure Vo/c = out unloaded in full sun. If Voc > 15V it can also be used.

Assume for now that PV3 = 15V, 300 mA.
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Panel combining:

It seems like that combining ALL panels in parallel will provide a usable 12V system.

If all panels are ABOUT 15V optimally loaded = Vmp then they can be placed in parallel.
IF this works Imp ~~~= 3.75A.
The 40 W panel predominates so work to use that well.

Under conditions of ~= constant sun during the test period connect combinations of panel to a test load. Adding PV1 then PV4 then PV2 then PV3 should give increasing voltage and/or current.

• A test load could be a resistor that reasonably fully loads all panels at once and which can withstand the wattage. As Isum ~= 3.75V, if Vmp is assumed to be 15V then Rmp ~= V/I = 15 / 3.75 ~= 4 Ohms.
  Power total ~= 60 Watts (if 'lucky') so eg 6 x 27 Ohm, 10W resistors in parallel or ... .
  Or a say 55W 12V automobile headlight bulb (non linear but indicative).

• Or a test load can be a meter set to 10A and short circuiting the panels.
  Isc is usually about 1.1 to 1.2 x Imp.
  Shorting is not as good a test as parallel connected loading because eg a 3A x 12Vmp panel and a 1A x 18Vmp panel may give a parallel Isc of around 4.5A BUT not show that while about 4A will be provided at 12V, only about 1A will be provided at 18V.

The only panels that should not be combined in parallel are those which reduce the output at about the Vmp of PV1, or any which provide so little gain at PV1 Vmp as to not be worth the effort.

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Charge Controller:

Charge controllers SC1 and SC2 have high enough current & power ratings to handle the whole PV array. Use whichever best suits.

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Battery

Use a rechargeable battery which is in good condition and which has ample capacity.
Without going through your list in detail - the 41N batteries appear to be small and non rechargeable.

IF they are in good condition the 2 x Yuasa 20 H 12V batteries could be good.
The 65-100 sounds superb if in good condition.
The SCS200 also sounds excellent, if ... .

Your PV panels may provide up to around 3.5A in bright sun - maybe less.
What is your location. In eg San Francisco The Gaisma solar site says you get under 2 hours equivalent full sun in winter and over 7 hours equivalent in summer.
7 hours at say 3.5A (almost impossible to achieve) =~ 25 Ah - so a 100 Ah battery would be good and a 200 Ah even better.