Hi All
I am looking to replace an existing 12 volt 200Ah c20 lead acid set up with a diy powerwall,
my existing system is
2 x 80wp 21 Voc solar panels
6.6 amp PWM stecca charge control
charging 2 x 125Ah rolls @ 12 volts
this runs my 12v central heating and hot water pumps and control gear for the wood burning range,
It uses between 10 and 20 Ah per day depending on how long we run it for, I could reduce the consumption a bit if I changed the wiring to get rid of a couple of auto relays,,
In the summer the same 12 volt system powers the control gear an pumps for the solar hot water collector,, I have way power more than I need in the summer an think its been a factor in the demise of the existing lead acid batteries, so I need to find a use for the extra in the summer,, anyway,,
I know 12volt is not good for Lithium cells (thanks to your site) so im looking at doing the following,
2 x panels in series to get 24v
MPPT suitable size
7s30p Lithium cell 18650
I have seen new cells at 5000mAh by Ultra fire dont know if anyone has any experience of these?
then into a dc/dc converter to 12v supplying the existing system,
It looks like I will need some sort of BMS some pointers would be appreciated on suitable set ups as well as any comments thoughts, suggestions on my plan,,
Thanks for reading
Graham
I am looking to replace an existing 12 volt 200Ah c20 lead acid set up with a diy powerwall,
my existing system is
2 x 80wp 21 Voc solar panels
6.6 amp PWM stecca charge control
charging 2 x 125Ah rolls @ 12 volts
this runs my 12v central heating and hot water pumps and control gear for the wood burning range,
It uses between 10 and 20 Ah per day depending on how long we run it for, I could reduce the consumption a bit if I changed the wiring to get rid of a couple of auto relays,,
In the summer the same 12 volt system powers the control gear an pumps for the solar hot water collector,, I have way power more than I need in the summer an think its been a factor in the demise of the existing lead acid batteries, so I need to find a use for the extra in the summer,, anyway,,
I know 12volt is not good for Lithium cells (thanks to your site) so im looking at doing the following,
2 x panels in series to get 24v
MPPT suitable size
7s30p Lithium cell 18650
I have seen new cells at 5000mAh by Ultra fire dont know if anyone has any experience of these?
then into a dc/dc converter to 12v supplying the existing system,
It looks like I will need some sort of BMS some pointers would be appreciated on suitable set ups as well as any comments thoughts, suggestions on my plan,,
Thanks for reading
Graham