how many batteries
put a deposit on a small jayco toy hauler (octane 222). will pick it up next week. will be mostly used in campgrounds but few times a year i go to nascar races for 3-4 days at a time. have a generator...
Forum Discussion
pnichols wrote:
BF,
As you know, having as large a battery capacity as one either can fit or can afford means one may have battery capacity so large that - all or most of the time - one uses and recharges only the "very top" of their battery capacity. This means that one's battery(ies) will last the longest time possible, all other things being considered.
Staying as shallow as possible on daily battery discharge cycles is a good thing. One can achieve this simultaneous with heavy daily use of battery energy if their overall battery capacity is large. Also in emergency situations (such as extended low sun-light conditions or being otherwise "stranded"), one may thank their lucky stars that their battery capacity was "larger than normally necessary".
IMHO one need only match daily charging capacity (be it solar or generator) to whatever the average daily battery discharge levels are ... NOT match daily charging capacity to around 50% of whatever battery capacity is installed if installed capacity is large.
Phil, you forgot that staying at the top end of the SOC band means it will take forever to do the recharge of the needed AH. Which is why you do 50-80s or 50-90s to keep generator time at something reasonable.
You can have too much battery so that when you get to 50% you only need to get back to 70% to be good for the AH, but if you stop there they will sulfate like crazy, and get big progressive capacity loss from successive incomplete cycles too. If you have an idea of your AH usage, you can get the bank sized right to do your 50-90s in a short time where the 40% of the capacity matches your usage.
