diy solar

diy solar

Need A Little Help

barbixy

New Member
Joined
Mar 19, 2020
Messages
23
Hi all,
I'm planning a solar install on my Chevy Express. I was thinking either two 100ah LifePo4 batteries, or one 200ah LifeP4o4 and two 175w panels mounted on my roof rack. For the charge controller I was thinking the Tracer 4515BN 40amp. Not sure yet what inverter, but probably a 1500w pure sine wave of some kind. I had a few questions:
I plan to mount everything (except the panels of course) inside a plywood box, so all the wiring etc is hidden from the camper interior.
1) do I connect the panels in series or parallel?
2) Do I need a fuse between any of these components or between the panels and components? If so what size?
3) Are these components self cooling? Or do people put little (noisy) fans inside the box?
4) how do you connect the AC plug on the inverter to the 110 plug that will be mounted someplace else in the van, to plug in a laptop etc, without opening the box up?
5) Do I need a battery box for LifePO4 batteries, or can they just sit on plywood?
6) any other thoughts you might have that would help me would be greatly appreciated... There's no shop help on this so i need to figure it out on my own, with your help of course.

THANK YOU!!!
 
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If that is Tracer 4215, supports Voc up to 150V (cold conditions), so series voltage of two 175W panels would be good.


Fuse - LiFePO4 batteries can deliver quite a few thousand amps into a dead short. The internal resistance figures I've seen suggest as much as 20,000A. A class T fuse is best. Amperage rating depends on inverter continuous current draw, but a 1500W inverter running off 12V probably pulls 140A, so at least 175A fuse maybe 200A fuse. And use 2/0 cable.

Smaller fuse between charge controller and the big fuse.

Inverters and charge controllers are self cooling, and may have (noisy) fans built in.
If you stick them in a box that blocks air flow, they will get hot. Have vents top and bottom.
You could add a fan to vent the box, with thermostat. You could add a (quiet) fan to blow air through the inverter ad over the charge controller to keep them cool more quietly.

If your inverter has an electric socket build in, you can use a power strip to extend it.
Try to get an inverter with remote control switch, which you can mount outside the box. Or else have a hole to reach switch.
 
Thank you!
I found these panels, however I'm not sure if their voltage is compatible with two, 12v batteries. Which voltage number on the spec sheet is the one to consider? I was thinking two of these, and two 100ah lithium batteries. The 175w panels I was considering have flimsy plastic corners and cost $20 more each than these Rich panels, so I decided against them.
Also, the Rich wiring diagram looks like they're wired in parallel?
Thanks for the charge controller spec sheet, if I knew which voltage number to look at on panel spec I could tell if these panels will work with the 4215 Tracer.
 
Here's the Rich panels, 25watts more each and $20 less on the Rich website and $30 less on Amazon, than the 175w Renogy with plastic corners @$220.

Can I use these with two 12V batteries?

Thank you again.
 
Don't pay $1/watt, $200 for a 200W panel.
Even new panels can be had for half that price, but you can get used for $0.12 to $0.30/watt.

You can use any panels with 12V batteries so long as you get an MPPT charge controller, not PWM.
(A single "12V" panel (18 Vmp) is often too low voltage for MPPT, but two in series works.
 
The thing is, I'm spending A LOT for a roof rack, and I'd like to be able to use half/one side of it for paddleboards, surfboards, maybe a kayak or storage etc, which I won't be able to do if I install solar panels side by side, or wider square panels that cover more than half of one side of the rack, which are the lower cost panels. These $200 panels are narrow enough that I can fit two of them longways in a column, and still use the other half of the rack without covering the panels up.
But, where would I find those lower cost panels? I definitely want 400w of panels.
 
SanTan solar is one liquidator many of us are happy with. But truck shipping of pallets makes smaller purchases less economical.

Check Craigslist, eBay (sort by distance to find local for pickup).
 
For used solar panels these guys are good I hear, I haven't used them yet but I am planning to in the near future.
Question 4: Use any kind of extension cable coming out of the box, OR just run normal wire for the plug and terminate the other end into a 110 20 amp male plug
You do not need a 'fuse' you DO need some sort of breaker OR fuse though, between battery and inverter and from PV to charge controller, and of course from inverter to whatever AC loads you run, but with 1500w inverters they usually have a built in breaker, so two breaker boxes, 3 if the inverter doesn't come with one. Remember to get DC RATED BREAKERS/FUSES for the DC side! DC causes much much larger arcs when they disconnect then AC does for the same voltage. Typically, a 600v AC rated breaker is good for about 80v DC, but if the breaker/fuse isn't DC rated, don't use it for DC!
Are good DC breakers for solar, useable on both the PV and the battery side.

There is nothing about "self cooling" you will need to have airflow through the box or the electronics will heat up and eventually get to hot. either a vent on the top to let hot air out and smaller vents on the bottom to draw air in, or a forced system (read small noisy fan) pushing air through the box.
 
Thank you! What do you mean "the DC side"? The only DC I'm aware of are the DC plugs in the inverter and those are wired inside.
 
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DC side is batteries and solar. Anything that is running Direct Current IE DC.
 
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