diy solar

diy solar

Female newbie! Honest opinions and advice please!

Electronewbie

New Member
Joined
Oct 27, 2021
Messages
9
Hey! Long post but there’d be a super grateful small English person if you read it and answered ?

I'd like your honest opinion/advice please.

I am a female with little knowledge of electrical circuits but I currently have a simple solar panel set up to power two lights in my stables and plug in devices to an inverter.

I would like to know if you think it's easy enough for me to upgrade my system to a 40W panel.
I already have the panel, I already have the correct charge controller (both have been at home for 18 months until someone helps me with them) the lights are already wired in and just have a plug running from the switch (which is usually plugged into the inverter) and I already have the right inverter.

I know that the inverter is man enough for everything I need as it already works well, it's just that the solar panel is too small to trickle charge the battery without me having to lug it home every two weeks to charged it manually.
I would like to know if you guys think it’s possible for lil old me to set this up.

Nb… im not stupid ? but Im not massively experienced. If there was a step by step guide I’d be fine to follow it but people seem to have different opinions of in which order to connect things and whether I need fuses for example.

I’d like the solar panel on my stables roof (I have the bracket and correct adhesive (don’t want to make holes).

So questions are

1. Do I need any fuses? If so where?
2. I’m going to need to extend the wiring from the panel. What type of wiring? Specific thickness?
3. What order to connect everything? Solar panel last so I don’t fry the controller?? All electricians are telling me the opposite but what I’ve read suggests otherwise.

Am I nuts for thinking of attempting this? Haha! I’m just sick of waiting for help and I’m pretty sure if I knew how To do it (rather than everyone telling me different) I’d be fine!

I’d be massively grateful for any advice and your honest opinions, thank you

Inverter is 2kw continuous and 3kw peak.

Charge controller pic attached and solar panel particulars attached.
 

Attachments

  • 52C524B0-E731-4C43-AEAA-48C5A5BD9775.jpeg
    52C524B0-E731-4C43-AEAA-48C5A5BD9775.jpeg
    143.3 KB · Views: 20
  • E464E314-005C-4A08-9A01-CD7AEC2F2865.jpeg
    E464E314-005C-4A08-9A01-CD7AEC2F2865.jpeg
    189.3 KB · Views: 21
Last edited:
1. Yes. You should have a fuse between your battery and your inverter on the (+) wire and between your PWM controller and battery on the (+) wire. You do not need one between your solar panel and charge controller. Fuses should be sized based on 1.25X the peak current capability of the wire.
2. Depends on the distance between the panel and charge controller. There are lots of PV wires available with built-in MC4 connectors of varying length; typically 10 and 12awg.
3. a) Battery to controller, b) panels to controller.

45W isn't much and may only offset a small portion of your use. Regular depletion of lead-acid batteries damages them. You want to avoid discharging them more than 50% of their capacity for optimal life.

If you wish to avoid taking the battery home and charging it ever again, you need to assess your usage and size your solar accordingly.

Good luck!
 
Sure nothing to it , you just need all the stuff to hook it up .
What battery do you use ? Type amp hours
 
1. Yes. You should have a fuse between your battery and your inverter on the (+) wire and between your PWM controller and battery on the (+) wire. You do not need one between your solar panel and charge controller. Fuses should be sized based on 1.25X the peak current capability of the wire.
2. Depends on the distance between the panel and charge controller. There are lots of PV wires available with built-in MC4 connectors of varying length; typically 10 and 12awg.
3. a) Battery to controller, b) panels to controller.

45W isn't much and may only offset a small portion of your use. Regular depletion of lead-acid batteries damages them. You want to avoid discharging them more than 50% of their capacity for optimal life.

If you wish to avoid taking the battery home and charging it ever again, you need to assess your usage and size your solar accordingly.

Good luck!
Thanks so much for your reply!
I will only use the lights for one hour per day so a friend told me that size panel should be fine but I’m just going off people opinions I guess!
 
Inverter 2000W
PV panel 40W
battery 100 Ah

Seriously under-paneled.

Battery - is that FLA "flooded lead-acid" wet cell? Or sealed, like AGM or Gel?
If FLA, it wants 12A, so 150W or more of panels for a 12V battery
If sealed, I'm not sure how slow a trickle charge is OK, but can probably take 10A, maybe 20A.

Expect 5 to 6 effective hours of sun in the summer, 1 or 2 in the winter (check an "insolation" website for your location.)
6 x 40W = 240 Wh, 1 x 40W = 40 Wh
Compare that to battery, 12 x 100 = 1200 Wh.

The inverter probably wastes 25W just sitting there, so if turned on for one hour, there goes 25Wh. Left on 24 hours per day, 600Wh drained.

Check out Craigslist for local used or extra PV panels.
You might pay between $0.10 and $0.50/watt.

Catch is, most big cheap panels are 24V or 36V
You have a PWM charge controller, which needs a 12V panel (Vmp in the 17V to 20V range.)
To use the higher voltage panels you would need an MPPT charge controller

 
Thanks for replying! Lots of info.

I can buy a new panel that’s no problem, I was just obviously mistaken thinking the one I had was enough.

I did get a bit lost with your post so I’m thinking maybe I’m in over my head but as I’m only using two low energy lights and a radio for 1-2 hours per day I didn’t think it mattered the capacity of the Inverter. I got a large one so It had enough energy and could power my clippers once every 3 months over winter. Apart form that my current set up (with a tiny 10w battery.. originally installed for one small light) lasts over two weeks.
Inverter is switched off for 22 hours per day.

I’m not sure about the battery type.. but I assumed wet cell. I’ve attached the info from the website. Link below :)

I’ll have a look at a larger panel then with a different type of charge controller.

I might try hooking up current panel to my battery that powers my electric fence. It only uses a tiny bit of power and lasts 7 weeks usually so any extra would be great.

Thanks for your help

 
One trick I can give you that I figured out when I wired a 120v LED light into my garden shed is that instead of having the light switch turn the light on and off, just have it turn the inverter on and off. Granted I'm just using a little 300w modified sine which is still overkill for my 40w light, but it prevents the battery drain from the inverters idle consumption. It might be worthwhile to get a small cheapie inverter for the lights and just run the big guy when it's shearing time. That inverter is calling for about 200 amps of draw and fuse on that poor little battery,

Yes, that battery is a wet cell FLA. Good cheap option and will last years with a little bit of maintenance.

Connection order always starts from the battery, so battery -> controller, battery -> inverter, controller -> panels. You're right in thinking that the panels get connected up last.

With only 1 set of panels per controller there's no need for fuses there, but some people feel better having a fuse between the SCC and the batteries, although at 40w I think it's overkill. I highly recommend getting a MPPT controller for the new larger panels, you'll get a LOT more power per hour of sunlight than if you used the cheapie PWM controllers. Have you ever looked into the difference between PWM and MPPT?

As to wire run, the rule of thumb is the thicker the better, but don't go so thick that you can't get the wire into the holes! :) Most MC4 connectors and controllers can take a 10AWG wire but no larger without doing some elbows deep research into minutia.

Lastly, the only thing that you being a woman means is that @ghostwriter66 will be along to tell you to sucker the guys into lifting the heavy things off the top shelf. :)

Welcome!
 
For such small loads and runtime as you are asking about, the 40W panel can work, but you may take too long recovering from running the clippers. A lead acid battery needs a full recharge each day, and 40w will take more time if the battery is discharged far.
I would get 100W panel at least.
 
Rather long response, but the system could have more panels and batteries added to it. The idle draw and loads are often more than we think, especially if we can’t measure them.

40 watts is plenty to run a small light system, but often there’s hidden things behind the 40 watts.
=====
I Measured some idle draw on my RV with 12 volts. THe stereo when left on pulled .5 amps, the fridge also pulled .5 amps. So, with a 100 ah battery that adds up. That could be 24 amps over a 24 hour period. That’s half the usable power.

If you have access to a clamp ammeter that you can measure your battery with, that could be extremely helpful. The idle draw could really eat into a small 100 ah battery pack.

Even with those two items shut off, there’s some thing, could be the 12 volt smoke alarms, or who knows what that cause enough drain to kill the battery in a couple weeks of sitting.

Your idle draw could be way different.

For the inverter my idle draw is 1 amp on a 12 volt 2 kw inverter. That adds up, even for a couple hours. When I turn that inverter on to run a microwave, it jumps to 155 amps. THat kills the battery, what makes it worst is the Puekert effect where the battery struggles to keep up, kind of like less MPG at high speeds, so the battery dies even quicker at those high uses.

My lights run anywhere from .4 amps up to 10 amps, depending what I have on.
 
Hey! Long post but there’d be a super grateful small English person if you read it and answered ?

I'd like your honest opinion/advice please.

I am a female with little knowledge of electrical circuits but I currently have a simple solar panel set up to power two lights in my stables and plug in devices to an inverter.

I would like to know if you think it's easy enough for me to upgrade my system to a 40W panel.
I already have the panel, I already have the correct charge controller (both have been at home for 18 months until someone helps me with them) the lights are already wired in and just have a plug running from the switch (which is usually plugged into the inverter) and I already have the right inverter.

I know that the inverter is man enough for everything I need as it already works well, it's just that the solar panel is too small to trickle charge the battery without me having to lug it home every two weeks to charged it manually.
I would like to know if you guys think it’s possible for lil old me to set this up.

Nb… im not stupid ? but Im not massively experienced. If there was a step by step guide I’d be fine to follow it but people seem to have different opinions of in which order to connect things and whether I need fuses for example.

I’d like the solar panel on my stables roof (I have the bracket and correct adhesive (don’t want to make holes).

So questions are

1. Do I need any fuses? If so where?
2. I’m going to need to extend the wiring from the panel. What type of wiring? Specific thickness?
3. What order to connect everything? Solar panel last so I don’t fry the controller?? All electricians are telling me the opposite but what I’ve read suggests otherwise.

Am I nuts for thinking of attempting this? Haha! I’m just sick of waiting for help and I’m pretty sure if I knew how To do it (rather than everyone telling me different) I’d be fine!

I’d be massively grateful for any advice and your honest opinions, thank you

Inverter is 2kw continuous and 3kw peak.

Charge controller pic attached and solar panel particulars attached.
Fuses: you will get about 3 Amps from 40 Watt panel, don’t need fuses there, but should have a 2 pole disconnect switch from the panel. 2 Pole DC rated Miniature Circuit Breaker in a small MCB box would be cheapest (AC breakers are cheaper, some have a DC rating too, and used on DC Telecoms). Some small Amp breakers are relatively expensive, 16/20/25A is ok, it’s just a disconnect, and you should disconnect solar before disconnecting battery from a SCC.
4mm2 cable is ok, beware of cheap copper coated Aluminium cable, eg Glowmax. On the roof it should be solar cable, for weather and UV resistance.
Connect battery first, then panel to SCC.
Fuses should be used between battery and SCC, at least 5A greater than expected charge current, up to double. Fuse recommended between battery and inverter, similar rating.
You could buy 12 volt LED lights, and not need an inverter, which has maybe 80-90% conversion efficiency. You might not find bayonet fitting types, but Edison screw LED bulbs are available, as are Osca German make, with thin wire, and a hanging hook.
It’s quite straightforward really, good luck
 
I think with a small inverter you should do ok .
this radio uses very little power on ac power 3/4 watts .
A small 2/300 watt samlex inverter should work fine for clippers .
this should work for your 2 hours a day lites , radio
The clippers would need more solar .
I like to have at least 100watts of solar 2 100amp hour
but more solar would be better .
 

Attachments

  • C842EB1E-7B23-4995-ACEA-CA139DDEF6DF.jpeg
    C842EB1E-7B23-4995-ACEA-CA139DDEF6DF.jpeg
    437 KB · Views: 3
  • FE6FBD9F-8E82-4613-BC84-72A82E0AF5FC.jpeg
    FE6FBD9F-8E82-4613-BC84-72A82E0AF5FC.jpeg
    670.2 KB · Views: 3
One trick I can give you that I figured out when I wired a 120v LED light into my garden shed is that instead of having the light switch turn the light on and off, just have it turn the inverter on and off. Granted I'm just using a little 300w modified sine which is still overkill for my 40w light, but it prevents the battery drain from the inverters idle consumption. It might be worthwhile to get a small cheapie inverter for the lights and just run the big guy when it's shearing time. That inverter is calling for about 200 amps of draw and fuse on that poor little battery,

Yes, that battery is a wet cell FLA. Good cheap option and will last years with a little bit of maintenance.

Connection order always starts from the battery, so battery -> controller, battery -> inverter, controller -> panels. You're right in thinking that the panels get connected up last.

With only 1 set of panels per controller there's no need for fuses there, but some people feel better having a fuse between the SCC and the batteries, although at 40w I think it's overkill. I highly recommend getting a MPPT controller for the new larger panels, you'll get a LOT more power per hour of sunlight than if you used the cheapie PWM controllers. Have you ever looked into the difference between PWM and MPPT?

As to wire run, the rule of thumb is the thicker the better, but don't go so thick that you can't get the wire into the holes! :) Most MC4 connectors and controllers can take a 10AWG wire but no larger without doing some elbows deep research into minutia.

Lastly, the only thing that you being a woman means is that @ghostwriter66 will be along to tell you to sucker the guys into lifting the heavy things off the top shelf. :)

Welcome!

Thank so much! This was really helpful and in nice simple English for me haha! perfect.
Yes I read that you should switch off the inverter rather than just the load so ive been in th ehabit of doing that. Funnily enough we used to have a 300w inverter which used to do fine, until the clippers were attached.. they would run for long enough just not as fast as they should do whichn is why i went hell for leather and bought a much bigger inverter. Maybe slight overkill haha!

Ill have a read up on MPPT controllers thank you

Haha! Ghost writer has the right idea :) !!

Thanks so much
 
For such small loads and runtime as you are asking about, the 40W panel can work, but you may take too long recovering from running the clippers. A lead acid battery needs a full recharge each day, and 40w will take more time if the battery is discharged far.
I would get 100W panel at least.
Thank you, this makes a lot of sense. I think a larger panel is the way I will go :)
 
Fuses: you will get about 3 Amps from 40 Watt panel, don’t need fuses there, but should have a 2 pole disconnect switch from the panel. 2 Pole DC rated Miniature Circuit Breaker in a small MCB box would be cheapest (AC breakers are cheaper, some have a DC rating too, and used on DC Telecoms). Some small Amp breakers are relatively expensive, 16/20/25A is ok, it’s just a disconnect, and you should disconnect solar before disconnecting battery from a SCC.
4mm2 cable is ok, beware of cheap copper coated Aluminium cable, eg Glowmax. On the roof it should be solar cable, for weather and UV resistance.
Connect battery first, then panel to SCC.
Fuses should be used between battery and SCC, at least 5A greater than expected charge current, up to double. Fuse recommended between battery and inverter, similar rating.
You could buy 12 volt LED lights, and not need an inverter, which has maybe 80-90% conversion efficiency. You might not find bayonet fitting types, but Edison screw LED bulbs are available, as are Osca German make, with thin wire, and a hanging hook.
It’s quite straightforward really, good luck
Thank you MikeBou, that really helps! I've written a few notes down from that. I think I need to change my current light set up. My brother was an electrician many years ago so he put up lights with a plug, old school style and so, being off grid, we needed the inverter to plug them into. (He doesnt know much about solar).
I think I need to start again using LEDs and miss out the inverter, thank you.

Ill maybe set up the inverter on a completely separate circuit with its own panel for anything I need to plug in :)
 
I think with a small inverter you should do ok .
this radio uses very little power on ac power 3/4 watts .
A small 2/300 watt samlex inverter should work fine for clippers .
this should work for your 2 hours a day lites , radio
The clippers would need more solar .
I like to have at least 100watts of solar 2 100amp hour
but more solar would be better .
Thank so much for answering.
Silly question.. the 100amp hours you mentioned is obviously the devices I am thinking of using?
I just had a quick search and the clippers only state Watts and Volts.
Voltage 240v
Wattage 45w
I'm sure there's a equation but that's over my head!
Regardless I think a larger panel is my next move.. thank you :)
 
Thank so much for answering.
Silly question.. the 100amp hours you mentioned is obviously the devices I am thinking of using?
I just had a quick search and the clippers only state Watts and Volts.
Voltage 240v
Wattage 45w
I'm sure there's a equation but that's over my head!
Regardless I think a larger panel is my next move.. thank you :)
100Amp Hours is the size of the 'Bucket' of energy the battery can carry... (100 amps for 1 hour or 1 amp for 100hrs, and the range in between)
Amps x Volts = Watts, So Watts / Volts = Amps... (watts are constant, they are the actual measurement of 'Work' being done)...
You would need an inverter capable of providing 240v (imitating Mains voltage) and with enough 'beef' to provide 45w. The big 3000w inverter does this, with aplomb.
But, it is taking those watts from the battery, at 12v... so 45w / 12v = 3.75amps (plus whatever overhead the inverter has. Bigger has more overhead)
Lead Acid batts can be damaged when drawn down below 50% capacity, so you'd have ~10hrs (50AmpHrs / ~5amps)with that battery when it's haircut time.
The problem is recovering those watts (amps) when the sun is shining...

Running lights through the inverter is effective, but can be wasteful. what about sourcing some automotive/RV (12v) Led lights, and running them directly off the battery? Wiring them is low voltage, so not harmful if you touch bare wires... (they can be sourced through Amazon, https://www.amazon.ca/PEAKTOW-PTR00...rds=12+volt+led+lights&qid=1635437860&sr=8-12 )
 
Clipper wattage 45W
Battery voltage 12V
45W / 12V = ~ 4A draw on battery to power clippers.

Exact number varies with inverter efficiency and battery voltage (state of charge) bug good enough for estimates.
100 Ah battery with 4A draw for 10 hours would consume 4A x 10 h = 40 Ah or 40% of 100 Ah.

Alternatively, 12V x 100 Ah = 1200 Wh
45W = 45 Wh per hour of operation

PV panels also have watts ratings, but a bit trickier. Assume they only deliver about 75% of rating, e.g. 100W panel puts 75W into battery.
Sun varies with season and time of day. An "Insolation" web page will consider that an the angle you oriented your panel (fixed panel may point at sun in summer, but off-angle in winter) and you'll find you may get 7 hours effective sun in summer (75W x 7 hours = 425 Wh/day) but only 1 hour in winter (75W x 1 hour = 75 Wh/day)

MPPT will usually get more of the PV panel's available watts, PWM usually gets less.
 
Back
Top