One of the things I've regretted about
our solar set-up
is not spending more on
batteries. It made sense at the time, because we were looking to stretch our limited
budget as far as we could. However, our battery bank isn't large enough to
power the freezer and fridge for more than a day and a half without sun.
Fortunately, we usually have the grid to plug back into, but the primary
reason for this small system is to preserve food in our hot climate if
the power is out for an extended period of time.
In the back of my mind, I've thought that if we were ever able to utilize our
remaining two solar panels, we could use the original battery bank for those
and invest in a larger one for the fridge/freezer set-up. Now that
we finally have those panels up,
that's what we decided to do.
Ordering batteries off the internet is the most expensive option, so we went
back to the same folks who sold us
our first set of batteries. Originally, we got 6-volt golf cart batteries. With the help of the sales
guy, we were able get industrial 6-volt floor scrubber/sweeper batteries.
Our six golf cart batteries are 235 amp hours each, with a total of
705 amp hours for the battery bank. These floor scrubber batteries are 330
amp hours each, so we can increase our electricity storage quite a bit. Of
course, more amp hours meant they are more expensive, and it took some
discussion to decide on how many. Pairs are required for solar wiring, and
six would give us approximately 990 amp hours. But eight would give us 1320
amp hours!
For technophiles, here's how that works:
Wiring components in series increases voltage.
Wiring components in parallel increases amperage.
Our system is small, so 12 volts is perfect. To create a 12-volt system from 6-volt batteries,
we connect pairs of batteries in series (connecting negative terminals to
positive). That increases voltage.
6 volts + 6 volts = 12 volts
To increase amperage, we connect the pairs in parallel (connecting all
the negative terminals together, and all the positive terminals
together). That increases amperage.
330 amp hours x 4 pairs = 1320 amp hours
The result is a 12-volt, 1320 AH battery bank.
For a visual example of how the wiring is done, here is our original battery bank. The blue is series wiring (neg to pos). The green is parallel wiring (neg to neg and pos to pos).
Anyway, even though the money had been earmarked for this purpose, it's
still difficult to make expensive purchases because we do it so rarely.
Finally, Dan asked what would give me the most peace of mind, so we got
eight!
Batteries do have a lifespan, which was something to consider when making this
switch. We've taken good care of our first battery bank by regularly checking
the specific gravity and water level of each cell, plus not discharging too
deeply. So we should still get quite a few years out of the old bank.
Now that we have the batteries, the next step is to build a box to house them. Dan's working on that.
11 comments:
I too struggle with large purchases but rarely regret them.
Ed, we find it to be the same, I think because such purchases are carefully thought out. It's those impulse buys that are the problem!
I think there's a lot of risk in an expensive purchase, where you can't afford an expensive mistake. It's enough to give you pause. That said, I've never regretted the "buy the best" the times I've done it. So there's that.
Also thank you for the lesson in battery use and pairing. Always learn something here.
My batteries are dying. I can only run off the solar panels when the sun is hitting them. It helped after our recent storm to run the fridge and freezers during the day, but I really wish I could afford to replace them.
Boud, I've always said that the blessing of being poor is that I can't afford to make mistakes! I agree with "buy the best" or in this case, buy the biggest.
Tpals, I'm sorry to hear that and fear we'll be in the same boat some day. And the price of batteries is (of course) going up. It's worrisome.
I don't understand the math, but it sounds like a great upgrade! ;0D
Let the sun shine in!
Daisy, the math is electricity stuff, which I confess stumped me profoundly for the longest time. It's difficult to understand (and remember!) definitions for things that can't be seen, such as voltage, current, and power. One of the reasons I put it in my blog posts is for a record and a reminder!
Wow! That is such a great purchase, and you are correct! Peace of mind, INDEED! Great post, Leigh!
Thanks, Wyomingheart!
Leigh, from an inexperienced opinion, I think going with eight makes the most sense if for nothing else, the piece of mind. As Ed said, in larger purchases such as this or ones that will essentially be long term purchases, I have rarely regretted spending the extra money.
Off topic Leigh, I sent a pic to you and didn't know if you received it. I took your email off of your profile and it had a weird prefix ******@ mail.com, was that the right email? You may have my email address when I comment if you would prefer a little privacy.
Post a Comment