Batteries First setup

[brackstone]

I am starting my first off grid system which will run a chest freezer 100W, pond pumps 50W, Tv for about 2hr 42W and 500W computer now and again. Over time this will increase as the system increases.

Solar will be 900 watts at first hoping to increase to 1800w over the year

Inverter will be 2Kw but may look at the 3Kw inverter 24v.

Batteries I will get lithium in future but cannot afford them now with all the setup, so my question is will two ABS 230Ah batteries be ok for the first year or two. Total voltage will be 24v

Thanks for any advice

Pair Of ABS L230 Leisure Batteries 230ah | ABS Batteries

ABS 230ah Ampere Leisure Battery These large Leisure batteries are designed for powering all types of electrical and motorised equipment where no mains are supplied. Portable Energy for Solar Panels * Caravans * Motorhomes * Yachts * Boats * Narrowboats * RV's * Motor Boats * Totally maintenance...

advancedbatterysupplies.co.uk

 

[DThames]

If that computer is a PC, I suggest you put a power meter on it and get some better numbers. 500watts for a PC is not reasonable unless it has some type of heater built in. While a computer might have a 500w power supply, that doesn't mean it pulls 500w.

Is this system required to keep the freezer running or do you have grid power or generator power if your battery is low?

 

[brackstone]

PC was not a major issue but take you point was going by the power supply have not checked it out

I will be setting up a low voltage contactor, with battery shunt if the battery gets to low it will shut down the inverter and switch to grid supply so no worries about loosing any food. Just a matter of weather the battery's will be good to hold up over night and recharge in the day

 

[DThames]

Lead acid should not be discharged more than 50% unless you are okay with shortening their life. So about 100-110 amp hour discharge would keep you above that 50%. 100 amp hours at 24v is 2400 watt hours. That would carry the freezer for about 24 hours, if it was running 100w, 24/7. Do the pumps run at night?

 

[brackstone]

This is what i was hoping keep the freezer running at night. Pumps can be switch off at night. My intention is to install the min setup then increase solar to max the roof can take about 1800 watts then start saving for lithium EVE cells. so these batteries only need to last 1 to 2 years

 

[Rednecktek]

so these batteries only need to last 1 to 2 years

If they are only a short lifespan expectancy, you can't really beat the value of the WallyWorld 29DC batteries. Yes, only good for 60Ah usable power (50% DoD), but at about $100 out the door they're super cheap and should work well enough until your next upgrade phase.

500watts for a PC is not reasonable unless it has some type of heater built in.

In the tech world we call that a "GPU" Unless you still have a Pentium-4 Rotisserie.

Inverter will be 2Kw but may look at the 3Kw inverter 24v.

I'd recommend a good 3Kw as inverters are expensive and you should only have to buy one once.

My intention is to install the min setup then increase solar to max the roof can take about 1800 watts

You're about the perfect candidate for a pallet of used panels. Buy in bulk to make the insane shipping cost more manageable and mount as many as you can. I'm certain you'll find a use for any spares that don't fit on the roof.

 

[brackstone]

If they are only a short lifespan expectancy, you can't really beat the value of the WallyWorld 29DC batteries. Yes, only good for 60Ah usable power (50% DoD), but at about $100 out the door they're super cheap and should work well enough until your next upgrade phase.


In the tech world we call that a "GPU" Unless you still have a Pentium-4 Rotisserie.


I'd recommend a good 3Kw as inverters are expensive and you should only have to buy one once.


You're about the perfect candidate for a pallet of used panels. Buy in bulk to make the insane shipping cost more manageable and mount as many as you can. I'm certain you'll find a use for any spares that don't fit on the roof.

Thanks for tips. I'm in UK so these batteries will be no good. If I was in US I would go with EVE as they have a warehouse in US so not so expensive

I was thinking 2-3kw, initially was going with 3kw then thought 2kw and get a second one then setup is big enough to run parallel (not connected together) but you are right if the batteries can handle the 3kh then this will be better

I have been looking for second hand solar but not much around in UK. What is for sale second hand is really old tech so very inefficient. 300W panel will be £210 each so not to bad

 

[Rednecktek]

In the UK they're called "Leisure Batteries" and a 100Ah is still about 100 give or take.

As for used panels... yyeeaahhh... hopefully someone from that side of the pond will be in shortly with the local version.

What is for sale second hand is really old tech so very inefficient.

Eeehhh, not really. The efficiency has gone from maybe 19% to 22%, the panels just got larger to make more power. 210 for a 300w panel new is a pretty good deal though.