Ronski's Solar & battery DIY build with whole house backup

Associate
Joined
14 Aug 2006
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1,976
Location
Land of Dragons
Here's what I calculated, presuming I've used the correct values


I just use the simple method of adding the total Watts of the string, divide by your battery volts, gives you your max amps on that string.
You don't usually get to those numbers for more than a few seconds, say after bright sun comes out from behind the clouds and it spikes.

No cable losses are accounted for just the ball park number of Amps

Nice to see you're going to use 6mm cable for the panels...good choice

Finally the electrician is coming to the rental property on Thursday to change the inverter, lost a month of good solar/FIT payment :(


You will be running your house like this when you're done with the install, just using the cheap rate.

PLhTlSj.jpg
 
Soldato
Joined
17 Jul 2007
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24,529
Location
Solihull-Florida
Yes the bottoms of the cells are still covered.

Cell-Bottoms.jpg


All the cells are physically good, there is no damage, only thing I have noticed is the terminals are welded on slightly crooked, some are worse than others though. I don't think this will cause any issues, as there is some leeway in the supplied busbars, but I may well use these flexible busbars - need to check hole spacing.

I've measured the voltage, and every cell is 3.295v, can't carry out any other checks as I don't have the equipment yet.


LF280-K-crooked-terminals.jpg


Make your own cables if possible.

And don't go above 3.6V or your cells will die faster.
 
Soldato
Joined
25 Mar 2004
Posts
15,896
Location
Fareham
If you're on a capped rate you could switch to Bulb, they have an EV tariff (doesn't require an EV), I've just switched and I'm paying exactly the same rate, and when the time comes I'll switch to the EV tariff. Bulb may possibly be bought by Octopus. Unless changing to a fixed price contract most suppliers won't take you on.

Have you had any luck getting onto it? My SMETS1 meter is still not working so I can't switch as the option is unavailable for my meter.

Website just says this on the EV tariff bit:

We're still setting up your meter in our systems

Please try signing up after you get your next statement. Sorry to keep you waiting.

Edit - I do wonder if people can actually really get onto it at the moment - https://community.bulb.co.uk/t/ev-tariff-disaster/112226/8
 
Soldato
Joined
25 Mar 2004
Posts
15,896
Location
Fareham
I haven't tried yet, but my smart meters haven't worked since the end of July. I might try contacting Bulb to see if they will replace them.

I don't think we'll have much luck getting Bulb to swap them, I've just posted in the other solar thread, perhaps going to Agile will be a good move short term.

Think Octopus will replace for SMETS2.
 
Associate
Joined
14 Aug 2006
Posts
1,976
Location
Land of Dragons
Hydraulic Wire Crimper, next on your list of stuff to buy, it never ends!, if you don't have one already.
I'd go the 16Ton version for the longer length handles, makes crimping a bit easier, you still have to use all your strength :)
A lot of crimping to do.
 
Soldato
OP
Joined
3 Dec 2012
Posts
3,641
Location
Kent, much sunnier than Scotland
I asked Fogstar for the EVE test data spread sheet last night, they emailed it through this morning.

My cells range from 290.6 AH to 294.1 AH, if that is the case it will give a 15kWh battery. Once I get my battery tester I will test some cells.

The only odd thing is the spreadsheet has a production date, and creation date value for each cell, all of which are the 15 June 2022, which differs from what the Lifepo4 app says, which is January this year for most of them.
Hydraulic Wire Crimper, next on your list of stuff to buy, it never ends!, if you don't have one already.
I'd go the 16Ton version for the longer length handles, makes crimping a bit easier, you still have to use all your strength :)
A lot of crimping to do.

I didn't, I do now though, it arrived yesterday :D Only the 8t one though.

8t-crimper.jpg


Last night I ordered all the aluminium for my solar mounting brackets.
 
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