35ah battery for Shur Flo 4008

[ADK_XJ]

I've got the Harbor Freight 35 amp hour "thunderbolt" solar deep cycle battery powering my Shur Flo 4008 pump with 75-100 taps, it's powered by 100 watts of solar but we've had mostly overcast weather recently with not much direct sunlight.

Do I need to invest in a larger amp hour battery?

[mainebackswoodssyrup]

We run big group 31 deep cycles from the auto store with 300W of solar panels on a 4048 pump and still have to swap them out and charge every couple of days. Even if the sun is out. So I would definitely have a charger handy.

[red/one]

100 watts of solar may not be enough from what I've read. I'm not an expert though. We run an Interstate SRM-24 deep cycle battery on a 4008 (not solar) and swap it out every 24hrs for a freshly charged one. We have not stretched it past 24hrs but I am sure it will last.

[UB29]

Three of my Shurflo 12V setups have 4008 pumps; and one with a 4048.
Each setup has 300W of solar, charging two SLI24MDC Duracell Ultra BCI Group 24M 12V 75AH 500CCA Flooded Deep Cycle Marine & RV Batteries. I buy them at Batteries Plus, link below.
Never have a shutdown; even in cloudy or 24/7 runtime conditions.
Bill
https://www.batteriesplus.com/productdetails/sli24mdc

[maple flats]

Do you have the 100 watts where it will get full sun when the sun is out?
At my house I have 1710 watts solar on an off grid solar set up. they face south and are at the proper angle. I have $4,000 worth of flooded LA batteries and many times in winter I only get 100-300 watts of power comming in. A lot depends on whether there is any snow on the panels, just 2" on them cuts the power in from maybe 1500 watts to 150 watts, and 6" might cut it to 50 or so, 12" cuts it to zero in.
Do you keep snow off that 100 watt panel? does it get full sun or some shade? You also need to realize that the 100 watts are a 72F and full no cloud sun. while a panel under bright sun with no snow on it but plenty of sun reflecting on the panelfrom all directions and cold weather will actually give more than 100 watts. Next question, qhat is the wire gauge and distance between the panel and the battery? If too far or too light a gauge you are losing much of the potential power.
To maintain that 35 AH battery you might actually need 500 or even 1000 watts of panels and keep the panels clear of snow all the time.
On a seperate grid tied system I have over 6000 watts of panels, and when there is a full moon I get over 200 watts when the moon is nearly south at night., in the daytime I'll get 4000-6000, sometimes more in bright sun, especially when the temperatures are real cold, the colder the more effective solar panels are.

[Scm]

Do you have the 100 watts where it will get full sun when the sun is out?
At my house I have 1710 watts solar on an off grid solar set up. they face south and are at the proper angle. I have $4,000 worth of flooded LA batteries and many times in winter I only get 100-300 watts of power comming in. A lot depends on whether there is any snow on the panels, just 2" on them cuts the power in from maybe 1500 watts to 150 watts, and 6" might cut it to 50 or so, 12" cuts it to zero in.
Do you keep snow off that 100 watt panel? does it get full sun or some shade? You also need to realize that the 100 watts are a 72F and full no cloud sun. while a panel under bright sun with no snow on it but plenty of sun reflecting on the panelfrom all directions and cold weather will actually give more than 100 watts. Next question, qhat is the wire gauge and distance between the panel and the battery? If too far or too light a gauge you are losing much of the potential power.
To maintain that 35 AH battery you might actually need 500 or even 1000 watts of panels and keep the panels clear of snow all the time.
On a seperate grid tied system I have over 6000 watts of panels, and when there is a full moon I get over 200 watts when the moon is nearly south at night., in the daytime I'll get 4000-6000, sometimes more in bright sun, especially when the temperatures are real cold, the colder the more effective solar panels are.

The cold is usually not so good for the batteries.

[ADK_XJ]

Three of my Shurflo 12V setups have 4008 pumps; and one with a 4048.
Each setup has 300W of solar, charging two SLI24MDC Duracell Ultra BCI Group 24M 12V 75AH 500CCA Flooded Deep Cycle Marine & RV Batteries. I buy them at Batteries Plus, link below.
Never have a shutdown; even in cloudy or 24/7 runtime conditions.
Bill
https://www.batteriesplus.com/productdetails/sli24mdc Thanks, so that probably answers my question — I have nowhere near enough solar or battery capacity. For now, it will just be charging at night, I guess.

Is it possible my battery is toast if it's displaying an "E11 code" (which my manual says means it discharged below 11 volts)?

[ADK_XJ]

Do you have the 100 watts where it will get full sun when the sun is out?
At my house I have 1710 watts solar on an off grid solar set up. they face south and are at the proper angle. I have $4,000 worth of flooded LA batteries and many times in winter I only get 100-300 watts of power comming in. A lot depends on whether there is any snow on the panels, just 2" on them cuts the power in from maybe 1500 watts to 150 watts, and 6" might cut it to 50 or so, 12" cuts it to zero in.
Do you keep snow off that 100 watt panel? does it get full sun or some shade? You also need to realize that the 100 watts are a 72F and full no cloud sun. while a panel under bright sun with no snow on it but plenty of sun reflecting on the panelfrom all directions and cold weather will actually give more than 100 watts. Next question, qhat is the wire gauge and distance between the panel and the battery? If too far or too light a gauge you are losing much of the potential power.
To maintain that 35 AH battery you might actually need 500 or even 1000 watts of panels and keep the panels clear of snow all the time.
On a seperate grid tied system I have over 6000 watts of panels, and when there is a full moon I get over 200 watts when the moon is nearly south at night., in the daytime I'll get 4000-6000, sometimes more in bright sun, especially when the temperatures are real cold, the colder the more effective solar panels are. All good questions and appreciate your input...I definitely do not have the panels in full sun all day, so that is something I'm going to have to work on given it's in the middle of the woods and there's many hemlock stands in our forest.

It also sounds like I probably need more panels for the system...the cable to the battery is pretty short right now, which is also part of the challenge in placing the panels in full sun. I did buy a 25 foot cable extension that is 16ga but now I'm reading that might be too light? I think the current cable I have is 12ga.

[maple flats]

Both cable gauge and distance are very important. look up a voltage loss table or voltage loss calculator. feed in the data and see what you will lose at that voltage. Also realize that the voltage is not a constant on a solar panel, it will vary as the temperatures can the amount of sun on the panel change. If your panel says it's 12V,at 100 watts, that only means at a specific test temperature and full sun (actually a specific artificial light intensity). Such tests are generally made at 73F if memory serves me and the amount of light is always a specific intensity ( it will be similar to the sun's alumination on a perfectly clear day). It will also be on a perfectly clean panel, some minor dust on it or even the shadow of 1 small leaf or a very minor film of snow will alter it. While the 100 watt figure helps you know the approximate wattage it's just a starting point at best.
I suggest you watch a few videos by Will Prouse, they will teach you a lot. However they can also get you in big trouble. A few years back on one of my 2 off grid solar systems I needed new batteries, after using 8 large FLA (flooded lead acid) batteries at 6V each for about 10 yrs. I wanted some batteries that would last 2 or 3 times that long. I watched him teaching about Lithium Iron Phosphate (LiFePo4) batteries. That solar system has 1480 watts of rated solar array and I looked up 16 of the LiFePo4 batteries. At the time they were $2500.00. Will said that those batteries should never be charged when frozen and suggested an insulated cover along with a 65 watt heating mat. I bought it and set up the battery bank. Since it was being set up in my unheated sugarhouse I thought I was fine. They worked flawlessly for about 6 months, but then we got several inches of snow which covered the panels and I couldn't get in to the panels location for about 3-4 days. The system also had a BMS (battery management system) that was supposed to shut down the charge whenever the temperature fell below 35F. Well, the BMS failed and the 65 watt heater mat drew the batteries down too low, effectively killing them. I tried a fancy charger to bring the batteries back but nothing worked. Each battery cell was 3.3 v but they had been drawn down to about 1.2V. The fancy charger could be set to any voltage from 1V to 12V in .1v incriments. I tried voltages from about 1.5V all the way up in stages to 12V, nothing worked. $2500 worth of LiFePo4 batteries were toast. I believe the BMS is really the part that failed, it didn't shut down the charge as set and didn't shut off that 65 watt power draw. Because the batteries and the BMS came from China I had no place to even complain except on a solar forum. Since then LiFePo4 battery prices have come down , BMS's are better and some of those batteries can now be charged below freezing, but not super cold. Very expensive lesson! I had to sell a lot of syrup to come back from that loss.
I have now changed to absorbed glass mat batteries which can be charged at any temperature and have had no issues in the 3 yrs since I went with those new batteries.

[ADK_XJ]

Both cable gauge and distance are very important. look up a voltage loss table or voltage loss calculator. feed in the data and see what you will lose at that voltage. Also realize that the voltage is not a constant on a solar panel, it will vary as the temperatures can the amount of sun on the panel change. If your panel says it's 12V,at 100 watts, that only means at a specific test temperature and full sun (actually a specific artificial light intensity). Such tests are generally made at 73F if memory serves me and the amount of light is always a specific intensity ( it will be similar to the sun's alumination on a perfectly clear day). It will also be on a perfectly clean panel, some minor dust on it or even the shadow of 1 small leaf or a very minor film of snow will alter it. While the 100 watt figure helps you know the approximate wattage it's just a starting point at best.
I suggest you watch a few videos by Will Prouse, they will teach you a lot. However they can also get you in big trouble. A few years back on one of my 2 off grid solar systems I needed new batteries, after using 8 large FLA (flooded lead acid) batteries at 6V each for about 10 yrs. I wanted some batteries that would last 2 or 3 times that long. I watched him teaching about Lithium Iron Phosphate (LiFePo4) batteries. That solar system has 1480 watts of rated solar array and I looked up 16 of the LiFePo4 batteries. At the time they were $2500.00. Will said that those batteries should never be charged when frozen and suggested an insulated cover along with a 65 watt heating mat. I bought it and set up the battery bank. Since it was being set up in my unheated sugarhouse I thought I was fine. They worked flawlessly for about 6 months, but then we got several inches of snow which covered the panels and I couldn't get in to the panels location for about 3-4 days. The system also had a BMS (battery management system) that was supposed to shut down the charge whenever the temperature fell below 35F. Well, the BMS failed and the 65 watt heater mat drew the batteries down too low, effectively killing them. I tried a fancy charger to bring the batteries back but nothing worked. Each battery cell was 3.3 v but they had been drawn down to about 1.2V. The fancy charger could be set to any voltage from 1V to 12V in .1v incriments. I tried voltages from about 1.5V all the way up in stages to 12V, nothing worked. $2500 worth of LiFePo4 batteries were toast. I believe the BMS is really the part that failed, it didn't shut down the charge as set and didn't shut off that 65 watt power draw. Because the batteries and the BMS came from China I had no place to even complain except on a solar forum. Since then LiFePo4 battery prices have come down , BMS's are better and some of those batteries can now be charged below freezing, but not super cold. Very expensive lesson! I had to sell a lot of syrup to come back from that loss.
I have now changed to absorbed glass mat batteries which can be charged at any temperature and have had no issues in the 3 yrs since I went with those new batteries. wow, super helpful - I will definitely check out the resource you referenced.

Can I ask you then, do you think it's possible I ruined this new 12v lead acid battery I had hooked to my solar controller? My understanding was that the controller prevents the battery from over discharging but then when I saw the E11 alert and looked it up someone else referred to the battery as "toast after discharging to 11V"