Tweet
My batteries aren't holding a charge. They are about 4 years old Duracell sligc125 (235 20 ah). I have 4 330 watt panels, Midnite solar classic 150 charge controller, and giandel psw 4000w inverter. All wired for 24v. I do laundry when the sun is on the panels and wondering if that is effecting the abililty to hold a charge. We run about 5 lights, charge laptop and phone, watch tv about an hour a day and have a dc fridge. We turn the inverter off at night and when we get up in the morning the batteries are at about 23.5....I would love some help with this it may be that we just need new batteries? or maybe they aren't sized correctly? Does doing the laundry with a high efficiancy front loading washing machine and propane dryer rob from the battery stores? When I do the laundry it says there is about 28.5v....Still learning sorry if this seems like an obvious problem..
-
-
Sorry. If you are just listing your loads by name; washing machine, dryer, 5 lights, phone, etc it is really hard to know how many watt hours you are using.
You also did not mention how many of those 235Ah batteries you have. If it is only 2 then your 24v 235Ah system is too small. Your 1320watts of panels can generate maybe 55 amps of charging.which is good enough for a 550Ah battery system.
A 550Ah 24v system can safely generate about 3.3kWh (550Ah x 24V x 25% = 3300wh). If your night time loads are more than 3.3kWh then chances are you are killing your batteries and they can't be fully charged during the day when you run your day light loads. -
Oh ok I have 4 batteries and use approx. 8.70 kWh/day.Comment
-
That includes the washer and dryer that I only use when the panels are in full sun..Comment
-
So it's about 4.00kwh without the washer and dryer
Comment
-
Well on a good day that 1320watts can generate about 6.6kWh a day (1320w x 5 hours = 6600wh) So IMO you have been slowly killing your batteries using 8.7kWh/ day because your batteries can't be fully charged if you are using some of that 6.6kWh for your loads.
To be safe you need a battery system that can delivery that 8.7kWh using only 25% of its full load. That calculates to a 24V 1450Ah system. Which would require 145amps of charging, multiple CC's and a very big solar array.Comment
-
Thank you. I thought I understood that if I only use the washer and dryer when the panels are in full sun that the stored battery power wouldn't be used. Is that not correct?Comment
-
While the panels generate power for your loads they may not be "charging" the batteries. More than likely your panels are providing less then 100% of what you need so the batteries are providing the rest and are being drained.
If your system was big enough for your 8.7kWh then you would not be seeing a low battery in the morning.Comment
-
So if I stop using my washer and dryer and only use no more then 4kwh/day the batteries should hold a charge? And if they don't then I assume that I probably killed the batteries? When I replace the batteries will it be sufficient to replace them with the same ones I am using? Sorry about all of the questions I really appreciate the help. I don't want to spend money on new batteries only to destroy them again.Comment
-
Well your battery system is a 24V 470Ah which can safely provide you with about 3kWh a day (470Ah x 24v x 25% = 2820wh). So unless you get some of your 4kWh usage directly from the panels during the daytime otherwise you are draining the batteries about 35%. That usually means a shorter life then what the manufacturer states.
You have enough panel wattage to increase your battery system to 550Ah since you can generate 55 charging amps. The bigger battery will get you close to that 4kWh usage but it may still shorten the lifespan based on the depth of charge and cycle life posted by the battery manufacturer.Comment
Comment