diy solar

diy solar

hello........ and system and component vetting for solar/lithium/all-in-one backup

@smoothJoey " rated for 105c" - is this temperature rating or current (C rating of battery)?
105 celcius refers to the temperature rating for the insulation on the wire.
We want the over current protection to trip before the wire insulation melts.

Also - can you explain the difference:
"25 mm wire with a 150 amp breaker is good for the battery wires.
25 mm wire with a 150 amp fuse is good for the main wire "

There will be 2 aggregation points(typically busbars) one for the positive side and the other for the negative side.
For each battery the wire going from the positive battery terminal should have a 150 amp quality breaker as close to the positive terminal as possible.
The breaker handles over current protection and gives you a means of manual disconnect.
The will be another wire going from the aggregation point to the rest of the system it should have a quality 150 amp fuse.
The system I am proposing looks like this
Code:
legend {
    |U| = unfused busbar position
    |F| =   fused busbar postition
}

battery_0.pos<->breaker<->|U|
battery_1.pos<->breaker<->|U|
                          |F|<->growatt

battery_0.neg<----------->|U|
battery_1.neg<----------->|U|
                          |U|<->growatt
 
Last edited:
Aaaahh ok. So:
  • I have just learned that the WECO batteries come with a 100A fuse and disconnect (on/off switch) from the factory. Do I still need DC breakers on each +ve and must they still be 150A?
  • There are busbars for combining - I am not sure of rating.
 
Aaaahh ok. So:
  • I have just learned that the WECO batteries come with a 100A fuse and disconnect (on/off switch) from the factory. Do I still need DC breakers on each +ve and must they still be 150A?

Figured as much.
If the WECO's have a fuse and a disconnect you don't need the breakers/

  • There are busbars for combining - I am not sure of rating.

Not sure what you are saying here.
You diagram shows a midnite combiner + dc breaker which doesn't make sense.
Unless I'm mistaken about what a midnite combiner is.
In my experience a midnite combiner is for combining pv panel feeds and if therefore designed for higher voltage and much lower amperage.
 
new drawing
Code:
legend {
    |U| = unfused busbar position
    |F| =   fused busbar postition
    <-> = bi-directional traffic flow
}

battery_0.pos<->|U|
battery_1.pos<->|U|
                |F|<->growatt

battery_0.neg<->|U|
battery_1.neg<->|U|
                |U|<->growatt
 
I missed it before
The midnite box probably has busbars inside, confirm?
 
The quote lists it as "Midnite Enclosure Box" but the suppliers tell me the batteries come with a copper busbar to connect terminals.
Waiting on photo of this, and a schematic........
 
photos of the WECO battery terminals - they plan to parallel at the terminals with 25mm cable, then 35mm to Inverter ?
No busbars in Midnite Enclosure........
 

Attachments

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Please include pictures of the inside of the midnite enclosure.
 
photos of the WECO battery terminals - they plan to parallel at the terminals with 25mm cable, then 35mm to Inverter ?
No busbars in Midnite Enclosure........
Yes 25mm to each battery and 35mm from the aggregation point to the inverter is fine.
What is the temperature rating for the wire?
If there are no busbars in the Midnite enclosure what is the point of it?
How are they going to parallel the batteries?
 
Yes 25mm to each battery and 35mm from the aggregation point to the inverter is fine.
What is the temperature rating for the wire?
If there are no busbars in the Midnite enclosure what is the point of it?
How are they going to parallel the batteries?
Hey @smoothJoey attached the ,pdf for the Midnite combiner.
The batteries will be paralleled with the 25mm cables directly, then single 35mm +ve and -ve cables to inverter.
Batteries have factory installed 100A fuses and disconnect switches.
Looking at schematic the Midnite Enclosure is for the 175A DC breaker.............necessary?
 

Attachments

  • MNDC_Instructions.pdf
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  • SCHEMATIC.pdf
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That doesn't really tell me how the batteries are aggregated.
Not sure what you are asking for?
25mm cable connecting the 2 +ves on batteries together, same for 2 -ves.
One 35mm from common +ve terminal to Midnite and 175A DC breaker (then to +ve inverter) - one 35mm cable from common -ve direct to invererter -ve.
 
[QUOTE="ZorbatheGeek, post: 128844, member: 13700]
I live in SA but the system is in Kenya (for my parents).
[/QUOTE]
I spent a few months each year in Diani with occasional missions up country to Nanyuki. Lots of fun including the adventure caused by infrastructure.
 
[QUOTE="ZorbatheGeek, post: 128844, member: 13700]
I live in SA but the system is in Kenya (for my parents).
I spent a few months each year in Diani with occasional missions up country to Nanyuki. Lots of fun including the adventure caused by infrastructure.
[/QUOTE]
You found infrastructure?
Are we ever going to see Kiwis again or will you fade into the mist whilst the rest of us thrash it out with the virus?
 
I spent a few months each year in Diani with occasional missions up country to Nanyuki. Lots of fun including the adventure caused by infrastructure.
You found infrastructure?
Are we ever going to see Kiwis again or will you fade into the mist whilst the rest of us thrash it out with the virus?
[/QUOTE]
Diani was pretty civilised. I was there 2005 to 2008 for 3 months a year. Only passed through Nairobbery every now and then.

Couple of trips to SA too, climbing both around Jo’berg and Cape Town then another for a wedding in Kwazulu Natal before kayaking there and up at Vic Falls. Both awesome trips.
 
You found infrastructure?
Are we ever going to see Kiwis again or will you fade into the mist whilst the rest of us thrash it out with the virus?
Diani was pretty civilised. I was there 2005 to 2008 for 3 months a year. Only passed through Nairobbery every now and then.

Couple of trips to SA too, climbing both around Jo’berg and Cape Town then another for a wedding in Kwazulu Natal before kayaking there and up at Vic Falls. Both awesome trips.
[/QUOTE]
Huh - you've seen more of SA than I have. My folks are close to Diani - amazing beaches.
I was at school in Zim so had a chance to see Vic Falls and Kariba then - not the same place now
 
Not sure what you are asking for?
25mm cable connecting the 2 +ves on batteries together, same for 2 -ves.
One 35mm from common +ve terminal to Midnite and 175A DC breaker (then to +ve inverter) - one 35mm cable from common -ve direct to invererter -ve.
@smoothJoey - would appreciate your critique ^^
 

@smoothJoey you asked how the batteries are aggregated?
My reply:
Not sure what you are asking for?
25mm cable connecting the 2 +ves on batteries together, same for 2 -ves.
One 35mm from common +ve terminal to Midnite and 175A DC breaker (then to +ve inverter) - one 35mm cable from common -ve direct to invererter -ve.
 
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