Post
Topic
Board Mining
Re: GUIDE SETTING UP A SOLAR POWER SYSTEM
by
Trillium
on 28/09/2014, 01:43:45 UTC
You need to consider that for most battery types you cannot take the Ah rating and assume you can use 100% of this, because, cycling most kinds of batteries that deeply will permanently damage them. Be sure to carefully review the manufacturers tech sheet and find the max discharge depth, THEN calculate the "real" Ah rating from there. You can use this to calculate watt-hours or joules stored, which is a more meaningful piece of information for sizing your solar setup.

Also the 6 hour charging time above is unrealistic for a full charge for most battery types. Again you need to see the manufacturers spec sheets.

Cycling batteries between deep discharge states and back to their full capacity on a daily basis will also reduce their lifespan a lot more than usual as this is not considered standard operation. Arbitrary example: Most lead acid car batteries are discharged only less than 3% of their total capacity when starting a car, this will get them 3-5 years. Now take the same battery and discharge it 25-50% every 24 hours (if it's even possible to recharge it within spec limits that quick). Suddenly it lasts 6 months to 12 months tops.

A lot of people "make" battery storage systems for solar without researching how much they can drain their batteries, and how low of a voltage they can be taken. There are newer types which can take more punishment but there are always limits. I know a handful of people who've purchased various setups on ebay and of their own design only to wipe out $5k of batteries in half a year.