Seasonal use is a very frequent application that we design for in Mexico and Canada. Usually the seasonal residence sets for 6 months or longer. We have tried several methods of preserving flooded battery life including water-miser caps, short absorb times, no absorb time, 2 stage charge with the CV below gassing point and battery additives. Even so, more than half of our Mexico customers ruin batteries in 3-5 years due to prolonged periods without maintenance. The northern customers fair much better.
AGM’s perform much better than flooded but Lithium batteries are the best for long term non-use. You can simply discharge the battery to 50% then turn off the battery and walk away. When you return in 6-7 months, you will find it at the same SoC as when you left. For long term seasonal storage, that is all I recommend anymore. Larry Crutcher Starlight Solar Power Systems On Apr 30, 2016, at 12:54 PM, Dana <[email protected]> wrote: I have yet to see any FLA battery that can go 4-5 months without service. Typically a FLA needs an increased voltage to attain the same full charge rating at low temps, but you still require watering. I have clients with shut down houses and no load situations, we back off the Absorb set point voltage, & time at full & they still require watering. This thread started with “? I don't think the friend will be savvy enough to disconnect/connect them every year and I don't feel like having to go out there every season for them.” Based on this statement would you still recommend FAL batteries? I have clients with AGMS that are partial year residents & their AGMS are at 8-10 years and still doing the job. That said some clients even full time occupants cannot water & test the SG on a FLA to save their life (or sustain the batteries life). ---------------------------------------------------------------------------- Dana Orzel Great Solar Works, Inc - NABCEP # 051112-136 E - [email protected] - Web - solarwork.com O - 970.626.5253 C - 208.721.7003 "Responsible Technologies for Responsible People since 1988" P Please consider the environment before printing this email. From: RE-wrenches [mailto:[email protected]] On Behalf Of Starlight Solar Power Systems Sent: Saturday, April 30, 2016 1:28 PM To: RE-wrenches Subject: Re: [RE-wrenches] Winter Battery Maintenance I agree with Todd and Bob, leave the PV solar on, EQ off. I also instruct my customers to reduce the absorb timer to 0.1 hours. Since the battery is staying full, there is no need to spend time above cell gassing point which will increase water loss. Larry On Apr 30, 2016, at 10:28 AM, RE Ellison <[email protected] <mailto:[email protected]>> wrote: Everything mentioned so far works well however, if you're using a charge controller with an auto equalize function. Turn it off! I had a friend who has left his system over the winter for years with no issues and he shut his inverters off one year got back to the batteries being boiled dry After a lot of looking I figured out that it had gone into auto equalize and since the available sunshine per day was so low that it just kept trying all winter long to equalize the batteries There was a battery replacement in his future relatively quickly! It was an expensive lesson and I have since gone to all of the systems similar to that that I have installed over the years and shut off the auto equalize It's not an issue if somebody's around but they were gone for like five months and it was not a good outcome This particular system had three charge controllers, A combination of MX 60 and FM 60s I believe Just my thoughts, Bob ellison On Apr 30, 2016, at 12:43 PM, [email protected] <mailto:[email protected]> wrote: > i built a system for a friend's seasonal (summer) off-grid residence in > alaska. > > my instructions were simple: > leave the pv input & cc output breakers "on" and the load breakers (inverter, > dc sunfrost etc) "off". > > there was never a problem with winter freezing (even at -40f) until one year > when he accidently left the inverter's breaker on. even with no load, the > inverter's idle current drained the batteries and they froze. he only made > that mistake once. > > todd > > > > > > On Saturday, April 30, 2016 8:13am, "Solar" <[email protected] > <mailto:[email protected]>> said: > > > I do systems like this every year. (-45F winter temps). Use quick connects > > and > > train the customer on the batteries and their maintenance. Find bats with > > freeze > > points that match your area. I typically mount the modules at 90degree so > > snow > > never covers the array/module. > > > > I always recommend removal. I've thought about temp controlled incandescent > > lamp > > with a timer in a battery box for really cold nights.... Haven't got around > > to > > working through that design. > > > > I'm interested in the real seasoned off-grid installers thoughts about this. > > > > Jesse Dahl > > > > NABCEP PV Installation Professional > > IBEW Local 292 - Electrician > > Electrical/Solar PV Instructor - HCC > > > > Sent from my iPhone > > > > > On Apr 30, 2016, at 9:07 AM, AE Solar <[email protected] > > > <mailto:[email protected]>> > > wrote: > > > > > > Hey Wrenchers, > > > > > > A friend wants a very small battery set up at hunting cabin (like under > > > 1kW). > > It will only be used in the warmer months. I'm wondering what you all > > recommend > > for the batteries over the winter. I assume the ideal situation would be > > that they > > would be disconnected and brought somewhere warm for the winter (the cabin > > will be > > subject to below freezing temps)?? > > > > > > So long as they go into the colder months with a full charge is it > > > alright to > > leave them hooked up? I don't think the friend will be savvy enough to > > disconnect/connect them every year and I don't feel like having to go out > > there > > every season for them. > > > > > > Thanks for any thoughts. > > > Adam > > > > > > Adam Katzman > > > Autonomous Energies > > > _______________________________________________ List sponsored by Redwood Alliance List Address: [email protected] Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/[email protected]/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
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