SteveMosher
New member
- Joined
- Nov 1, 2016
- Messages
- 11
Any luck with these eBay sales I see?
SteveMosher said:Ok I think Im getting it now.
Im going up this week to pick up 6 of these batteries.
If I got my math in order that would be 55.6V - 53Ah - 3000Wh 55.6v 53Ah 18000Wh ? Or would the Ah also go up x6?
Chipper6 said:SteveMosher said:Ok I think Im getting it now.
Im going up this week to pick up 6 of these batteries.
If I got my math in order that would be 55.6V - 53Ah - 3000Wh 55.6v 53Ah 18000Wh ? Or would the Ah also go up x6?
Your 18000Whr math is correct (it includes 6x the Ah rating) since you will be connecting those 6 packs together in parallel, your total pack will be 55.6V X 318Ah (53x6) = ~18000Whr
That means, with a full battery pack and your prescribed load you can go 18000 Whr / 1700W = ~ 10.5 hrs
Now, based on how much solar you have, you may or may not be able to run your house during the day + fully charge the battery pack to run through the next night.... But that's the great thing about building it yourself, you just keep building...
Chipper6 said:OK. So for an example... using your 7 day average (147kW-hr / 7 days ) = 21 kW-hrs of solar produced per day (given it's November, this might be close to your annual average in California?)
If we assume your 1700W load is an all day average, that means you burn (1700W x 24 hrs) = 40.8kW-hrs (if your solar app doesn't give you your household daily usage, hop on PG&E's website, they give you pretty good numbers down to the hour). So, you have 40.8 - 21 = 19.8kWhrs that you are pulling from the grid each day.
If you really are using 40.8kW-hrs a day, and you want a battery system to help you get through the night, then you need more solar supply or cut back on your usage. If you want to not pull energy from the grid, then you need to match your daily usage with your daily solar supply, then you can store the excess solar power during the day and use it at night.
To stretch this thought experiment into two scenarios. One where you reduce your consumption, lets keep the 21kw-hr a day average. If you produce this energy over the span of 8 hours, then you'll be on battery for 16 hours (or 2/3rds of the day. 21kW-hr x 2/3rds = 14kW-hr . This means that your 18kW-hr battery pack will probably be ok unless you have a bad solar day then you may start pulling from the grid in the morning.
The other scenario is you can't reduce your consumption and you burn ~ 40kW-hrs a day. That means for 2/3rds of the day you'll need ~26.7 Kw-hr's of battery to get through the night, but you'll also need a solar array that is averaging 40kW-hrs of production / day.
Hope this helps.