Can I use telecom batteries

[GeorgeF]

If you consider an out-of-service telecom floatservice lead acid battery , I think you are wasting your money. If you consider a new one, perhaps it's wiser to choose true deep cycle batteries which are designed for daily or frequent cycling.

[Ampster]

I really don't provide detailed diagrams due to safety and insurance reasons.......

Otherwise having a small off grid system usually does not require a permit and should be safe if you follow Electric Code rules.

If I had risk management concerns such as you have I would have added a caveat that the poster should also always check the local AHJ because adding a circuit USUALLY does require a permit. Unless it is a small portable system a small system off grid would usually be connected to the breaker panel and be considered a circuit.

[Mike90250]

What he means is the battery cell level. For example, Tesla, Sonnen, BSLBATT solar batteries use brand new A-level cells.....

You mean properly matched and Binned cells ? where a group all test at 28.5ah ?

Much like a single batch of PV panels are "Binned" into groups of 300W, 305W, 310W and 315W panels ?

[SunEagle]

What's a "High Cell" ??

I am hoping he means does not have a high cycle count which is needed for solar batteries.

[Mike90250]

Telecom batteries tend not to have high cells etc.....

What's a "High Cell" ??

[Martynmiffy]

This is for a shipping container office I’m not really bothered about the insurance Claims lol

[SunEagle]

I really don't provide detailed diagrams due to safety and insurance reasons. I can tell you to look into websites that show you how to wire multiple batteries in parallel along with how to hook up 12V loads through some type of fuse block (similar to what you can find on either amazon or at a local car part store).

I am a big supporter of making sure all wiring and loads have the proper over current (fuse or circuit breaker) protection.

I am also not sure how you can use that inverter since it is for a grid tie system which may require engineering docs and permit approval from your AHJ and POCO. Otherwise having a small off grid system usually does not require a permit and should be safe if you follow Electric Code rules.

[Martynmiffy]

I’m learning something new every minute
but if I just used what I have to run the lights and a pc
would you be able to draw a wiring diagram from what I’ve sent using 12 v car batteries all same ah say 95ah? I have 3 solar panels a 30amp mppt controller and the tranergy inverter kit

[SunEagle]

When you say 400ah would that be the total ah for all the batteries connected up or would each one need to be 400ah
also if I run these in series would that add up the voltage per battery as opposed to keeping it at 12v in parallel?
reason I ask is that I’ve bought 12v strip lights

Most people try to wire 12V batteries in parallel to increase the total Amp hour of the system. I try to convince others that getting lower voltage with the desired Ah rating batteries and wire them in series to get the desired voltage. Since you should get around 40 charging amps from those panels a 400Ah battery system fits into your plan. If you can find 6V 400Ah batteries then get 2 and wired them in series otherwise look for lower voltage batteries at 400Ah and get enough to wire them in series to achieve 12V. If you can't find low voltage 400Ah batteries then you will have to wire what ever you find in parallel. That can cause one or more of those batteries to be charged and discharged unequally which will shorten the life.

Going off grid can be expensive due to battery cost and maintenance. Sometimes I suggest running a grid connection to the building that has the loads. If you compare the cost sometimes a grid connection gets you more power at a cheaper cost then a solar/battery system. Food for thought.

[Martynmiffy]

When you say 400ah would that be the total ah for all the batteries connected up or would each one need to be 400ah
also if I run these in series would that add up the voltage per battery as opposed to keeping it at 12v in parallel?
reason I ask is that I’ve bought 12v strip lights

[Martynmiffy]

Thankyou so much for your input ! Maybe I will skip the microwave and fridge !

[SunEagle]

I also purchased the above controller ? Would this work please

With 2 x 240w panels and that 40amp MPPT CC you can build a small off grid system. You might be able to go between a 320 to 480Ah 12V battery system. Where 400Ah is the middle and best size. The type of batteries should lower voltage (2V, 4V or 6V) FLA type wired in series. You also need to determine approximately what you will use in Watt Hours per day. Remember a 400Ah 12V battery system may only provide about 1200 watt hours (400Ah x 12V x 25% = 1200Wh) a day or less depending on how well they are charged and discharged. So having a large load like the microwave or frig can drain the batteries quickly.

You will also need a quality inverter that can change the battery DC voltage to an AC voltage to run that type of load. But an inverter may consume up to 10% of it's watt rating even without a load.

And finally there is no where on the earth that you can guarantee quality sunlight every day so at some time you will need a generator and charger to get your batteries up to full again.

[Martynmiffy]

I also purchased the above controller ? Would this work please

[Martynmiffy]

https://www.ebay.co.uk/itm/EPever-MP...-127635-2958-0

[Martynmiffy]

I am trying to run a small office off grid
pc or laptop and printer
12v lights
battery chargers for power tools
maybe a small fridge kettle microwave etc