# Inverter and batteries

#### Pineapple Smurf

##### Pineapple Beer Connoisseur
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I know I am a bit slow to understand. But how do I calculate the approximate hours I would get.

Lets say 2x105ah batteries, 24V, 300W draw.
I like the Display, you can see at what percentage your batteries are at, sweet.

Honestly cant give you a simple formula to work at coz formulas are never accurate, just too many variables to play with like your internal losses on the electronics, quality of electronics etc.

Simplest way is fully charge your rig, write down the time and yank the AC cord out of the wall socket.
Keep gaming, Netflixing etc until your battery indicator there hits the 50%.
Write time down again and do your maths. Plug AC cord back in and recharge.

My personal opinion is not go less than 25.4v across your bank, if it isnt enough time then get another 2x105aH and put them in series-parallel with your array.
Your system is designed to go to 25% battery or even 0% battery life but i would never in a million years do that to a lead acid battery. Only to lithium, but thats just me

#### RedViking

##### Nord of the South
I like the Display, you can see at what percentage your batteries are at, sweet.

Honestly cant give you a simple formula to work at coz formulas are never accurate, just too many variables to play with like your internal losses on the electronics, quality of electronics etc.

Simplest way is fully charge your rig, write down the time and yank the AC cord out of the wall socket.
Keep gaming, Netflixing etc until your battery indicator there hits the 50%.
Write time down again and do your maths. Plug AC cord back in and recharge.

My personal opinion is not go less than 25.4v across your bank, if it isnt enough time then get another 2x105aH and put them in series-parallel with your array.
Your system is designed to go to 25% battery or even 0% battery life but i would never in a million years do that to a lead acid battery. Only to lithium, but thats just me

View attachment 624314

Thanks. That Display is not very accurate I think. It fell from 100% to 75% within the first 5 minutes. But it stays at 75% for now. So far its been going for 35 minutes, currently 24.6V, 25% load. Printer, LED Panel Lights, 2xMonitors + PC normal load. I still plan to run the 3D printer but will do that when I get my Watt Meter replaced. Mmmm....

#### Pineapple Smurf

##### Pineapple Beer Connoisseur
Thanks. That Display is not very accurate I think. It fell from 100% to 75% within the first 5 minutes. But it stays at 75% for now. So far its been going for 35 minutes, currently 24.6V, 25% load. Printer, LED Panel Lights, 2xMonitors + PC normal load. I still plan to run the 3D printer but will do that when I get my Watt Meter replaced. Mmmm....
awesome, then add a volt meter like i have (Dairy Farmer posted links to some from Communica) I find that to be very accurate.
Just wire it between your positive and negative.
Ask for 1 that can do 24v as sometimes they will just give you a 12v one and it will pop

#### RedViking

##### Nord of the South
awesome, then add a volt meter like i have (Dairy Farmer posted links to some from Communica) I find that to be very accurate.
Just wire it between your positive and negative.
Ask for 1 that can do 24v as sometimes they will just give you a 12v one and it will pop
Will get a cheapy here, depending on courier fees and a fancy one from China.

Lol! A R50 volt meter is gonna cost R130 from Communica. I'll check what I can find locally.

Inverter lasted at least 3:30 hours before the 50% indication came on. I can maybe do without the LED & second monitor if I need to push it.

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#### Dairyfarmer

##### Executive Member
Ok got my replacement inverter from GeeWiz and the Menu button now works.

Only left to do is the cable to and from the DB. I have relocated the unit from where I initially had it. So have to get into the roof and move the cable.

All the cables the same length. Ring terminals are soldered on not crimped. The cable went in super tight to the terminals. I also got the tape out and did the ends of the cables.

I have put 2 x 63A 2 pole isolators next to the unit. This is where the cable from and to the DB will terminate. I will still be able to isolate the Eskom at the DB on the 3 phase isolator but wanted something at the unit. The cable below is a the same cable that I will use to the DB. It's a 4 core 4mm2 armoured cable. The piece I have used I removed the armour to make it more usable over the short distance, hence the need for a seperate earth.

Inverter specs.

#### ld13

##### Honorary Master
Sorry for the slight O/T - I am looking to get my hands on some 9ah 12V batteries. Found these, but I can for the life of me not see what their ah rating is?
http://www.csb-battery.com/english/01_product/02_detail.php?fid=7&pid=28
http://www.csb-battery.com/upfiles/dow01520317327.pdf
HR series HR 1234W 12V 34W
Voltage: 12V (6 cells per unit)
Capacity: 34W @15min-rate to 1.67V per cell @25℃ (77℉)
Am I missing something? How does the above translate to ah?

Ok got my replacement inverter from GeeWiz and the Menu button now works.
View attachment 626192

Nice setup you got there. How noisy is that bugger when working under some load?

#### Dairyfarmer

##### Executive Member
I've only run a single 10w LED spotlight on it using battery only, just to do a quick test. The fan was not noisy at all. I'll be putting it under load this weekend and hopefully permanently. Then I'll be able to judge the noise level. I have installed the unit in the laundry, so it won't be heard in the rest of the house.

#### Dairyfarmer

##### Executive Member
Finally got all the electrics sorted out. I split the DB into Eskom and Inverter. Each have their own earth leakage and 2 pole islotator. Phase one goes to the inverter, Phase 2 to geyser isloator, Phase 3 everything else. I have set the inverter to utility first and battery on utility fail. So I am using it in UPS mode.

Test on full mode. I turned everything on: Spots, all the lights, ceiling fan, 2 x box fans, 3 x bedside lights, 2 x pc's, laser mf printer, extractor fan, 3 x hone chargers, 2 x tv's with Android media players, 2 x routers, switch, wifi AP, Wisp AP, extractor hood and lights. The main tv with wifi router, router and Wisp AP are all connected to an ACP 1000vac server UPS. This I ran the batteries down to switch off before the test. I wanted it to work as hard as possible. I ended up with 1.2Kva. Turned off some lights, fans and 1 tv, to simulate normal load, and it dropped to around 0.75Kva. The double door Defy fridge drew another 0.3Kva when I left the doors open of 2 minutes and hit the fast freeze button. I have opted to leave the fridge off the system for now.

Fan noise is minimal but could be annoying if it were in the next room. It goes on and off all the time. Most likely the battery charger. I have sufficient in between that I cant hear it. But comparable to a quiet fridge.

I am still going to add a volt meter on across the fuses and a DC isolator per bank. That way I can turn a bank off and test each periodically. I have been told that the batteries I bought are a bit rubbish and they wont last long. I'm saving up for some 200Ah batteries. But I want to get 4 at once.

Anyone recommend a good make and supplier?

#### Geoff.D

##### Honorary Master
Batteries are as good as or as bad as you treat them! Monitor them regularly, make sure you charge them properly and watch the depth of discharge. That way, you should get maximum life out of them and once they do fail, then replace. Unless of course you can find a buyer and get a good price before that.

#### howardb

##### Expert Member
Very nice Dairyfarmer!
Busy doing my install with an RCT Axpert MKS5 and 2x 2.4kw Pylontech's (adding solar next month), and will probably end up doing similar by splitting phases on Eskom and the Inverter - do you have more pics of how your main DB looks after re-phasing everything to the Eskom/Inverter DB, as well as how you wired the 2x 63A 2 pole isolators next to the unit where the cable from and to the DB will terminate.

I'm wanting to get an idea of what it should look like before calling a professional sparkie to re-wire it all...

I also have 3 phase, but my DB is a spaghetti mess; honestly cannot fathom how they managed to get a CoC on it before we bought the house - will probably end up stripping out the current DB box, replacing with a new mounted box and re-wiring/re-phasing everything; this should also make it easier to split everything the way I want it between utility and inverter.

#### Geoff.D

##### Honorary Master
The way to understand all of this and the regulations is to try and put together a high level block diagram tyoe of circuit diagram, showing the "boundaries" between the various sections of what you are trying to do, and then establish new DB boards which become self evident later on.

#### Dairyfarmer

##### Executive Member
I also have 3 phase, but my DB is a spaghetti mess

Mine too.

First thing to do is see what plugs and lights are on each breaker. I was lucky that the plugs I didn't want (kitchen and laundry) were on separate breakers. When I last changed the geyser I installed it first on a 2 pole isolator (63A) then a single pole breaker (20A). Sparky suggested this as I can isolate both L and N and it doesn't run through the earth leakage.

I didn't have enough room on the main DB for the 2 new isolators and earth leakage you need for the inverter.

Going to the inverter you need a 2 pole isolator. A 2 pole isolates both live and neutral. I took Phase 1 from the load side (bottom) of the main breaker. If the isolator is on the main DB so I don't have to isolate Eskom main switch. Coming back from the inverter you need another 2 pole isolator and then an earth leakage.

All that sparky needs to do is move all the inverter run lines' neturals to a new bus bar which is fed from the inverter return neutral, not Eskom neutral.

I used one of the remaining phases for the geyser and the other of the plugs on on the inverter.

I used a spare 4 core 4mm2 cable I had laying around, but the sparky can use panel flex. I know some people who just use normal 2.5mm2 flex, the same you use for plugs. The problem is it is only rated to 3Kw. Your inverter can send a surge of almost double for a short burst (motor starting). So a 3kw can send a burst of 6Kw, double what the cable is rated at.

Eskom -> 3 pole isolator (main switch) (20 or 30A)
Phase 1 -> 2 pole isolator -> Inverter In (63A)
Phase 2 -> Earth Leakage -> Non inverter breakers (63A)
Phase 3 -> 2 pole inverter (63A) -> 30A single pole breaker -> geyser (you can use this same breaker to run spot lights, welders ect. Just remember it has no earth leakage)

2 pole isolator-> from inverter -> earth leakage -> breakers on inverter

#### howardb

##### Expert Member
Mine too.

First thing to do is see what plugs and lights are on each breaker. I was lucky that the plugs I didn't want (kitchen and laundry) were on separate breakers. When I last changed the geyser I installed it first on a 2 pole isolator (63A) then a single pole breaker (20A). Sparky suggested this as I can isolate both L and N and it doesn't run through the earth leakage.

I didn't have enough room on the main DB for the 2 new isolators and earth leakage you need for the inverter.

Going to the inverter you need a 2 pole isolator. A 2 pole isolates both live and neutral. I took Phase 1 from the load side (bottom) of the main breaker. If the isolator is on the main DB so I don't have to isolate Eskom main switch. Coming back from the inverter you need another 2 pole isolator and then an earth leakage.

All that sparky needs to do is move all the inverter run lines' neturals to a new bus bar which is fed from the inverter return neutral, not Eskom neutral.

I used one of the remaining phases for the geyser and the other of the plugs on on the inverter.

I used a spare 4 core 4mm2 cable I had laying around, but the sparky can use panel flex. I know some people who just use normal 2.5mm2 flex, the same you use for plugs. The problem is it is only rated to 3Kw. Your inverter can send a surge of almost double for a short burst (motor starting). So a 3kw can send a burst of 6Kw, double what the cable is rated at.

Eskom -> 3 pole isolator (main switch) (20 or 30A)
Phase 1 -> 2 pole isolator -> Inverter In (63A)
Phase 2 -> Earth Leakage -> Non inverter breakers (63A)
Phase 3 -> 2 pole inverter (63A) -> 30A single pole breaker -> geyser (you can use this same breaker to run spot lights, welders ect. Just remember it has no earth leakage)

2 pole isolator-> from inverter -> earth leakage -> breakers on inverter

Many thanks for this info, certainly helps!

You also indicated a few posts back that you'll fuse and add a DC isolator on the battery banks - do you know which ones you'll be getting? I'm looking for similar for the Pylon's -> inverter at 100A 2-pole, but cannot seem to find a DC isolator that will accommodate the thick battery cables - I also don't really want to cut the original cables as they have particular fittings to the batteries...

Was looking at the Chint or the Hager, but hesitant with the battery's cable size...the battery cables look like these - I suppose I could equally towards the ring lug end to place the isolators and fuses in line, but not really comfortable with doing that:

Any suggestions on 100A/120A inline fuses between the batteries and inverter?

#### Dairyfarmer

##### Executive Member
I got 100A ANL fuses from a car audio fitter. They were R150 each with the fuses. I can hook both leads for the battery to one terminal. I had to cut the arch out of the cover to get two cables in.

I decided not to buy a dc isolator. I can just remove the cable from the battery or remove the fuse.

Cable I went with 25mm2 welding cable. It's about R75/m and can handle 400A. The ring terminals were easy to put on. Strip the cable back and remove a few strands if needed to get the cable into the lug. Heat the lug with a big solder iron. Behind the ring is a hole and you push your solder in there till it's full. Far better than crimping. remember to orientate the ring terminals. They have a raise and a flat side. Cables connecting batteries must have both flat sides on the bottom. The rest just dry fit first to see. Especially where two cables go onto one post.

I used 10mm on the batteries, 8mm on the fuses and 6mm on the inverter. Get some red and black tape because the cable either blue, grey or green. Mark positive and negative ends with red and black respectively.

Cables must all be the same length. i.e the cables joining batteries in series must be the same length. Cables from the batteries to fuses must be the same length. Fuses to inverter the same length. Get your batteries as close to the inverter as possible. It is cheaper to raise the battery holder than to buy longer cable.

I'll take some close up pics today.

#### Jaws677

##### Expert Member
Cables must all be the same length. i.e the cables joining batteries in series must be the same length. Cables from the batteries to fuses must be the same length. Fuses to inverter the same length

There would be no technical reason to do this if you only have series batteries.

I see you have two sets of fuses on the postive and one on the negative wire. Again no technical reason to do this.

Simple way to parallel batteries without having an unequal voltage across batteries due to cable resistance

#### Dairyfarmer

##### Executive Member

DB Sorted out. You don't want to see the inside

Fuse and bus bar in one. Make sure you orientate the rings so flat side to flat side.

Soldered not crimped

Red and black tape. Green is for the one set of cables. Yellow for the other.

#### Dairyfarmer

##### Executive Member
There would be no technical reason to do this if you only have series batteries.

I see you have two sets of fuses on the postive and one on the negative wire. Again no technical reason to do this.
Batteries are in series and parallel. It is just common practice to make them all as close to the same length as possible. You also don't know if you are going to add more batteries in parallel at a later stage.

I am also using the fuses as bus bars. All the setups I have seen they fuse both ends. The same with din rail fuses.

#### Jaws677

##### Expert Member
Phase 3 -> 2 pole inverter (63A) -> 30A single pole breaker -> geyser (you can use this same breaker to run spot lights, welders ect. Just remember it has no earth leakage)

That would be illegal (SANS 10142-1)

#### Dairyfarmer

##### Executive Member
That would be illegal (SANS 10142-1)
That's the way the sparky did it. I didn't fiddle with it at all. That was the only part of the db that I didn't have to rearrange.

#### howardb

##### Expert Member
View attachment 627282
DB Sorted out. You don't want to see the inside
View attachment 627286
Fuse and bus bar in one. Make sure you orientate the rings so flat side to flat side.
View attachment 627288
Soldered not crimped
View attachment 627290
Red and black tape. Green is for the one set of cables. Yellow for the other.
Great, thanks! Really good info.
I'm looking at getting either of these:

or

May also get some 175A-rated Anderson plugs for the battery disconnect if I can't find a suitable size isolator switch - will go to the local hardware or electrical shop and have a look at the actual sizing of the isolator switches and the max diameter cable they can take. Ideally I want to create a sub-DB off the main DB with everything inverter-connected in one place, so looking at the DIN sizing/boxes.

May also look at the Keto-00 battery disconnector/fusebox as a viable DIN option and eliminate the need for the above items:

Will use the standard 1 or 2-pole Hager's for the rest of the switching.