Batteriapans setup

Batteriapan

Member
Joined
Feb 20, 2017
Messages
35
Thought it could be nice todocument my progress on the forum.

Starting of with my 7s20p witha maximumcapacity ofabout 1kWh.

image_jmfgtx.jpg

Best cells (~2500mAh)in the top left pack, crappy cells (~1500mAh)in the bottom right pack.

Waiting for a couple of meters withshrink tube from Chinato isolate thewires before I can move on to the next step.


600W 24vpure sine inverter from Mercury. "Soft start" is supposed to mean1200W for upto 2 seconds. Payed just belowEUR 100 for it with shipping to Sweden.


image_ojurwd.jpg


I have no clue how good or bad this is, but from what I could read it seems quite nice.


2A type B circuit breaker to put on the inverter output. That means 480W, even though the inverter handle short burstsup to 1200W. But I don't want to put any strain on the cells while I only have 7s20p.


image_fsteho.jpg


The inverter has blade fuses, but I of course prefer to use acircuit breaker...


I was actually considering a 2A type C or D circuit breaker to allow short bursts up to 600W, but wasn't able to find any detailed specifications for circuit breakers that told me exactly for how long it would allow the bursts. So rather safe than sorry.


40A circuit breaker I'll be putting between the battery and the inverter. Still waiting for it from Taiwanthough...


image_kqkdnn.jpg
 

Minatugar

Member
Joined
Oct 8, 2016
Messages
56
Just a suggestion. When building your packs try to mix the cells through all your packs so every pack has an even capacity. You will find that your lowest capacity pack will crash first dragging everything else down.
 

Batteriapan

Member
Joined
Feb 20, 2017
Messages
35
FiremanDIYPowerwall said:
Just a suggestion. When building your packs try to mix the cells through all your packs so every pack has an even capacity. You will find that your lowest capacity pack will crash first dragging everything else down.

Hi, thanks for the suggestion.

I'm still in the harvesting cells phase of the project. Plan to first double (7s40p)and thentripple (7s60p)the amount of cells. I hope to end upwith packs where the cellsare around 2300-2500mAh and with a low internal resistance. The old crappy packs will be stoved away, but until I have all good packs the crappy will be used inparallell to get the same capacity as the good packs.

It's going to take a bit of time, perhaps a year, before I get there.
 

daromer

Moderator
Staff member
Joined
Oct 8, 2016
Messages
5,564
As long as 1 string have even cells in every parallel pack it should be fine. Thats how im running my setup. Btw That 40A circuit breaker you have... Im pretty sure thats junk :) I have bought several of those from ebay and they did not trigger as they should nor did they work long term.

Just a tips :)

"Batteriapan" Svensk? :)
 

Batteriapan

Member
Joined
Feb 20, 2017
Messages
35
daromer said:
As long as 1 string have even cells in every parallel pack it should be fine. Thats how im running my setup. Btw That 40A circuit breaker you have... Im pretty sure thats junk :) I have bought several of those from ebay and they did not trigger as they should nor did they work long term.

Just a tips :)

"Batteriapan" Svensk? :)

Any suggestions to whatI couldreplace the crappy circuit breaker with? What I liked with the one I ordered is the format. It's a bit of a hassle to install a standard breaker without a standard rack, and I don't want to go mixing the AC with DC in the same rack.

Bor iSydvstra Skne med stuga i Norra Sknes lvskogar.
image_vlwffq.jpg
 

daromer

Moderator
Staff member
Joined
Oct 8, 2016
Messages
5,564
Northen skne? Not far from me then. Alvesta (Vxj) here :)

The DC breaker part is a hassle i agree. I was looking at those too but so many reports out there that they didnt work properly. I actualy dont have any main fuse right now but smaller fuses on each string.

Main breaker i have is either:
http://www.biltema.se/sv/Bil---MC/B...ombrytare/Huvudstrombrytare-250-A-2000020071/
or
http://www.biltema.se/sv/Bat/El/Strombrytare/Batterifranskiljare-2000022613/

For switching between i like this one:
http://www.ebay.com/itm/Blue-Sea-60...ash=item27e9265bf2:g:HosAAOSw-jhUEfMr&vxp=mtr

Biltema have too but i do not like it because you cannot switch from 0 to 1 or 2..

Regarding fuses i have ANL fuses here but have not added them yet. ANL can be found on biltema too and they would do the job pretty good :)
 
Top