Hi from Devon UK

[pug]

Hi to all I'm in Devon uk taking my first steps into solar power looking to have a play with running some of the power needs of my Koi pond setup with some power from the sun. After coming across 5x 35amp battery's I have probably jumped to soon and got a kit consisting of 4x 120w panels a charge controller and now have a stack of parts in my workshop ready to have a go at fitting the lot and wiring it up the weekend hear go's any tips before I start
Pug

[SunEagle]

Hello Devon and welcome to Solar Panel Talk

I believe you will have an issue with those 5 35Ah batteries. Wiring batteries in parallel will usually result in an early death of one or more due to uneven charging/discharging.

[pug]

I'm on a suck it and see with the battery they are sealed type 12v 35amp deep cycle they are brand still in the box's new but 6 years old been sat on a shelf they have all come up to over 13.6 volts and a very close match on my charger and show good. They where for a 12v endurance race cart that the school I work in use to race but no more. I bagged them for scrap cost so US that would be about $25 do they have to be an exact match. my playing around with electric stuff is mostly on the home built Ebike side of things
Pug

[SunEagle]

I'm on a suck it and see with the battery they are sealed type 12v 35amp deep cycle they are brand still in the box's new but 6 years old been sat on a shelf they have all come up to over 13.6 volts and a very close match on my charger and show good. They where for a 12v endurance race cart that the school I work in use to race but no more. I bagged them for scrap cost so US that would be about $25 do they have to be an exact match. my playing around with electric stuff is mostly on the home built Ebike side of things
Pug

A good battery system includes all of the same model battery. Any difference can create a higher resistance path which will affect both charging and discharging. When you wire batteries in parallel you increase the chances of different resistance paths. The end result is over using one or more of the units which kills them off earlier then expected.

Unfortunately even AGM type will slowly discharge just sitting in a controlled environment. I expect your batteries will last you a little but no where near the manufacture's cycle life or life span. Still not a bad choice for your first battery system to learn on.

[pug]

I should have looked into it a bit more before I started this but I jumped in after getting the battery's and have now got the solar system ready to fit in the workshop I video my Koi pond on a you tube channel this was last week I now have I think all the bits I need to fix plug and wire the lot. All the water pumps air pumps uv light total up to about 400w if I could put a quarter to half that load on to the solar full time or part time would put a smile on my face or even power the lot when the main power cuts as it seems to more often each year for 1 - 2 hours some times
Pug

[SunEagle]

I should have looked into it a bit more before I started this but I jumped in after getting the battery's and have now got the solar system ready to fit in the workshop I video my Koi pond on a you tube channel this was last week I now have I think all the bits I need to fix plug and wire the lot. All the water pumps air pumps uv light total up to about 400w if I could put a quarter to half that load on to the solar full time or part time would put a smile on my face or even power the lot when the main power cuts as it seems to more often each year for 1 - 2 hours some times
Pug

Well based on 5 x 35Ah batteries wired in parallel that will get you a 12V 175Ah system that has a 100% rating of 2100watt hours. If you discharge them 30% that will allow you to run about 630watt hours. Which unfortunately will get you less than 2 hours running 400watt load. If you use more than 30% you will reduce the life of those batteries. Remember if the sun isn't shining for a couple of days your system will not provide your pumps any power for most of that time.

In the long run you will need to reduce your load significantly or increase your battery system. Just remember that you will need charging amps that are between 1/12th to 1/8th the Ah rating of your batteries. So right now that comes to 14 to 21 amps.

[pug]

Thanks if I can power just the uv light at 55w and one of the two air pumps at 45w they don't need to run 24-7 as well maybe 8-10 hours of the day that would be a saving plus put a charge in my electric bike once a week. And know I then have backup power should I have a power cut and I have the power on hand for one water and one air pump for a hour or so this will be my first play around with this sort of thing when I put this weeks video on the pond on you tube I will pop a link up so you can see my cockups as I go thanks for your help and the help to come
Pug