Solar trolley battery

[Johan de Clercq]

Hi all at the solar community. I am still waiting on my order of a

NavaSolar BP18-3024 3kW 2.56kWh 24Vdc LifePO4 Trolley Inverter NV-BP18-3024.​

I already have 2 questions. As per the research I was able to find on the internet, you can not add another battery in parallel to this unit.

Is this because of the units battery management system, or can it be done?

2nd Question.

Will a single 700w solar panel be enough to recharge the battery in one day?

I stay in a complex that does not allow you to install solar panels on the roof.

I will have to install one in the window facing the sun, so it will not work optimally.

I live in South Africa, electricity is a luxury

Thank you for any feedback and advice.

 

[sunshine_eggo]

Hi all at the solar community. I am still waiting on my order of a

NavaSolar BP18-3024 3kW 2.56kWh 24Vdc LifePO4 Trolley Inverter NV-BP18-3024.​

I already have 2 questions. As per the research I was able to find on the internet, you can not add another battery in parallel to this unit.

Is this because of the units battery management system, or can it be done?

I have no idea. I can't imagine a reason it's not okay to parallel two same-cell-count, and same chemistry batteries together.

2nd Question.

Will a single 700w solar panel be enough to recharge the battery in one day?

Only in excellent solar conditions where the array is properly oriented and tilted with full unshaded exposure from sunrise to sunset.

I will have to install one in the window facing the sun, so it will not work optimally.

Windows block a very large portion of the available solar.

 

[Johan de Clercq]

Thank you @sunshine_eggo, I appreciate your advice.

 

[Brucey]

Hi all at the solar community. I am still waiting on my order of a

NavaSolar BP18-3024 3kW 2.56kWh 24Vdc LifePO4 Trolley Inverter NV-BP18-3024.​

I already have 2 questions. As per the research I was able to find on the internet, you can not add another battery in parallel to this unit.

Is this because of the units battery management system, or can it be done?

2nd Question.

Will a single 700w solar panel be enough to recharge the battery in one day?

I stay in a complex that does not allow you to install solar panels on the roof.

I will have to install one in the window facing the sun, so it will not work optimally.

I live in South Africa, electricity is a luxury

Thank you for any feedback and advice.

A true 700W panel is larger than a 4 foot by 8 foot sheet of plywood so that will need to be a very large window to fit unobstructed, and as eggo mentioned the glass and uv protective films etc will cripple your production regardless.

 

[Johan de Clercq]

Ok thank you Brucey. Yes that's not going to fit. I will look at other alternatives. For now just having backup power for 5 hrs will be good enough.

 

[Brucey]

Ok thank you Brucey. Yes that's not going to fit. I will look at other alternatives. For now just having backup power for 5 hrs will be good enough.

Do you have a balcony with some sun exposure? Common in some European countries to mount off the railings:

‘If 1.5m Germans have them there must be something in it’: how balcony solar is taking off

Balcony solar panels can save 30% on a typical household’s electricity bill and, with vertical surface area in cities larger than roof space, the appeal is clear

www.theguardian.com

 

[Johan de Clercq]

No I don't have a balcony, so I will have to mount it without any angles. In the southern hemisphere the panels should face north. I have a perfectly north facing window. I guess my question should actually be...what wattage panel could I use for this inverter trolley, keeping in mind the losses of the glass and the angle it's facing. There is sun all day where I stay. I just don't want to little power to not charge the battery at all.

 

[Brucey]

No I don't have a balcony, so I will have to mount it without any angles. In the southern hemisphere the panels should face north. I have a perfectly north facing window. I guess my question should actually be...what wattage panel could I use for this inverter trolley, keeping in mind the losses of the glass and the angle it's facing. There is sun all day where I stay. I just don't want to little power to not charge the battery at all.

I forget the exact numbers but I had a bifacial 115w panel behind treated glass patio slider doors and I'd be lucky get 10 or 15W out of it. Barely worthwhile.

 

[Johan de Clercq]

Ok I think I'll just abandon that idea for now. As long as the grid can charge the battery during the day It will work for my immediate needs.

Thanks Brucey.

 

[sunshine_eggo]

Ok I think I'll just abandon that idea for now. As long as the grid can charge the battery during the day It will work for my immediate needs.

Thanks Brucey.

This really sounds like the only viable solution.

If you had the option to temporarily hang panels from the N facing wall, you could build some lightweight and portable flex panel frames or simply hang them from hooks.

PVC ground mount:

S

Thread 'Cheap Dual Flex Panel Mobile/Tilting Stand'

Sep 19, 2020

Here’s a super lightweight and cheap adjustable stand design that I use for 100w flex panel pairs. Each unit costs <$15 to make and weighs <2 lbs. The tilt/kickstand adjusts with a wing nut and bolt — it can go from about 25-80 degrees and also fold in to lay the whole thing flat. All non-moving joints are held with small screws. 3/4” schedule 40 PVC for the main frame. 1/2” section fits into 1” on the kickstand arm.

This has made it much easier to chase the sun around our tree-lined yard and maximize panel output at different times of the day. I think the same setup with a few...

• SolarOhio
• Replies: 1
• Forum: Show and Tell

• 

And the flexible panels with holes:

 

[JustHank]

Do you have access to any smaller panels? Which would fit in the window with no shaded spots? I’d suggest trying one outside the window, then inside the window to see what percentage of full power you get. Of course, voltage is probably the only thing you can measure, but it would give you an idea of how much production you can expect through the window.

As @Brucey said, the window glass may block too much, but it would be good IMHO to verify that your window is not overly tinted or otherwise going to hinder production too much.

 

[Johan de Clercq]

Thank you JustHank and Brucey. Yes I can get smaller panels. I will give your idea a try.