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The start of my new 'Off grid' Solar install.


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Been thinking about batteries ....... 50Kbht for 12KWHr ...... I think I can build it cheaper.

One of these @3,400bht (16s, 48V, 150A with bluetooth)

A nice touch screen display @1,300bht

And 16 x 200AH LifePo4 batteries (used) @ 6,300bht/4 ....... Only bought 4 as I need to see they aren't selling swollen batteries.

 

Estimated total cost around 30Kbht for 10KWHr.

Not sure if I need an active balancer with this BMS, can buy it later if needed.

 

bms.jpg

screen.jpg

battery.jpg

Edited by BritManToo
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1 hour ago, BritManToo said:

Not sure if I need an active balancer with this BMS, can buy it later if needed.

 

The Daly BMS's are a bit weak on the balance front, fine with new cells but I'd get a "flying capacitor" balancer if you are going to go with the used CALB golf-cart cells.

 

Our cart cells are going strong, I'm going to get another pack in the next month or so. I might try the black "Sinopoly" cells, same size and style but a bit cheaper. 

 

The rigid plastic casing of these cells resists swelling pretty well, a couple of ours were very slightly swollen but it doesn't seem to affect the performance.

 

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Very interesting, im following your tread.. I see you commented on the free bus bars are a bit thin, i saw a youtube video on calb batteries and he told some sellers split up the busbars who is 4-5 this bars added together as one, is sold as single pieces. So its possible thats what you got.

 

Pink

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On 2/9/2022 at 10:53 AM, BritManToo said:

The first 4 of my batteries have arrived, not bad for 6,229bht delivered CoD.

No swelling and all reading 3.40V ........ the free bus bars are a bit thin though.

 

Which seller did you use?

 

As noted by @Pink7 the "original" bus bars are 5 or 6 thin copper strips with a heatshrink wrapper to hold them together. I have the same cells in one of my packs and actually split the bus bars myself as the seller didn't supply enough. Two of the thin strips per link is fine for >50A or so.

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43 minutes ago, Crossy said:

Which seller did you use?

 

As noted by @Pink7 the "original" bus bars are 5 or 6 thin copper strips with a heatshrink wrapper to hold them together. I have the same cells in one of my packs and actually split the bus bars myself as the seller didn't supply enough. Two of the thin strips per link is fine for >50A or so.

 

Crossy whats your experience with this type batteries? I see some sell used some sell new, are there new calb batteries sold at this price range here in Thailand or the all used?

Pink

Edited by Crossy
Fixed the quote.
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17 minutes ago, Pink7 said:

Crossy whats your experience with this type batteries? I see some sell used some sell new, are there new calb batteries sold at this price range here in Thailand or the all used?

Pink

 

The ones being sold as new are not!!

 

CALB have not made this style of cell for a number of years, so any on the market are definitely "used". Ours test at about 80% of new capacity, not bad for half the price of a genuine new cell and are lasting pretty well.

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The bus bars are a real problem.

Managed to find some thicker bars, 12 for just over 400bht (they only had 12) on Lazada.

The thin bars supplied will have to be doubled up 1" x 70mm x just under 1mm thick.

I really need them to take 120A ............ I might get away with 2mm ...........

 

I purchased an 'experimental' Daly 4s 100A BMS with Bluetooth just to play with the existing batteries.

Should arrive later today or tomorrow (2,500bht).

8 more cells on their way (I tell the seller I'll buy more if the ones that arrive are good, I felt buying 16 in one go was tempting fate)

So far I have ...........

IMG_20220210_143029.jpg

 

Another 'problem' purchase was a 120A 2 pole DC MCB/breaker so I can switch the battery on/off. Thai distributors wanted 400bht for this item ........ 150bht shipped from the Risin factory in China.

Edited by BritManToo
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Lithium batteries on Lazada are a massive minefield.

 

I got some decent 5,000mAh LiFePO4 32650 cells a couple of years back, but all the sellers now seem to have very definitely used and mostly worn out cells for sale.

 

Most annoying.

 

At least we know that the CALB cart cells are used and have an idea what to expect.

 

If you are serious about batteries a 20A capacity tester is a smart purchase, I have this one :- https://www.lazada.co.th/products/i3288677952-s12199092853.html

 

 

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Enough parts arrived to build my first 12V Lifepo4 200AH battery.

So the CALB terminals are M8, and the Daly 4s terminals are M6 .... search my bag of nuts/bolts/washers.

It only connects easily upside down .......... (Frankenstein would be proud)

Downloaded the app for my phone, connected the balance terminals and checked the voltages  went up in 3.3V increments.

 

0V on black to red wire 1 3.3V, wire 2 6.6V, wire 3 9.9V, wire 4 13.2V ..... all seemed good, so plugged in the balance plug.

Didn't bother initialising the BMS as there was a button on the Bluetooth dongle to switch it on.

Came up on my phone the moment I selected the Daly app.

 

Now if only I had a 12V load to test it all out with.

Never mind it ll appears to work off load, all the info is there, can change parameters, etc.

IMG_20220211_171808.thumb.jpg.9d6e640f578e876f1c73c0fe839bb90e.jpgIMG_20220211_171800.thumb.jpg.13aa6da95ffe10005ad8e5c1b37a6838.jpgIMG_20220211_171752.thumb.jpg.f5ce4db7eac2139615c84c46cde62f5a.jpg

 

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On 2/10/2022 at 2:32 PM, BritManToo said:

 

IMG_20220210_143029.jpg

 

Another 'problem' purchase was a 120A 2 pole DC MCB/breaker so I can switch the battery on/off. Thai distributors wanted 400bht for this item ........ 150bht shipped from the Risin factory in China.

Looks good, how you like the batteries? Do you have link to Risin for ordering breakers? When you expect your Inverter to arrive?

 

Pink

Edited by Pink7
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Just now, Pink7 said:

Looks good, how you like the batteries? Do you have link to Risin for ordering breakers? When you expect your Inverter to arrive?

Pink

Risin have a lot of good 'breaker' stuff at great prices, free delivery and fast from China.

https://www.lazada.co.th/products/i2867374375-s10463770614.html

 

My Inverter cleared China customs today, not fast as they took 7 days to dispatch.

No great rush, another 8 Lifepo4 cells arriving tomorrow. Will need 4 more after that.

Batteries seem decent enough, will need load tests to discover their true capacity.

I'll probably wait until i have all 16, as they seem to arrive all with the same Voltage from the shop, and I don't want to risk mixing things up too much. 

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56 minutes ago, BritManToo said:

Risin have a lot of good 'breaker' stuff at great prices, free delivery and fast from China.

https://www.lazada.co.th/products/i2867374375-s10463770614.html

 

My Inverter cleared China customs today, not fast as they took 7 days to dispatch.

No great rush, another 8 Lifepo4 cells arriving tomorrow. Will need 4 more after that.

Batteries seem decent enough, will need load tests to discover their true capacity.

I'll probably wait until i have all 16, as they seem to arrive all with the same Voltage from the shop, and I don't want to risk mixing things up too much. 

Thanks, that was a good deal.

 

Pink

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4 hours ago, Pink7 said:

What solar panels and how many panels you will setup BritManToo?

 

Pink

I think I'll get 5 x 340w panels, probably half cuts as they don't seem any more expensive.

 

Back to my battery build ........... connected it to my 1kW UPS and pulled the mains plug out.

Just been testing the first 4 ....... 260-350w load for 4 hours gave me 50% left.

This was powering my computer, 65" LCD Tv, router, sound bar, 2x NAS playing music from YouTube.

So that's around 1.2kWHr for 50% discharge which is more than I expected from s/h batteries.

IMG_20220213_104355.jpg

 

Didn't screenshot at the start but it was on around 97% @ 13.3V

Screenshot_20220213_104149_com.inuker.bluetooth.daliy.jpg

 

4 hours later ........

Screenshot_20220213_141800_com.inuker.bluetooth.daliy.thumb.jpg.89b2e1a659e465953d580b02b603101e.jpg

 

Now charging. Doesn't look like I need active balance the Daly BMS matched the cells perfectly. Cells ended up at about 1c above ambient temp.

Screenshot_20220213_141846_com.inuker.bluetooth.daliy.jpg

 

Another 8 cells just arrived.

Edited by BritManToo
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1 hour ago, BritManToo said:

So that's around 1.2kWHr for 50% discharge which is more than I expected from s/h batteries.

 

1200Whr @ 12.5V is about 96Ahr, not bad for 50% of 200Ahr. Of course a lot depends upon just how accurate your "50%" is.

 

I see your Daly is reading -ve current on discharge. I have three 16S units, two read +ve on discharge the 3rd reads -ve. Apparently it's a common problem and can't be fixed even with a firmware update.

 

When I get my round-tuit I'll make a simple ESP8266 based "flipper" so at least they all read the same.

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10 minutes ago, BritManToo said:

My Suoer 1kW inverter switches itself over from mains to battery when the grid goes off.

With this 4 cell battery my entertainment corner will work for 8hrs without mains power.

 

Once my new 5kW5 inverter arrives, and I've built my 16 cell 48V battery, my living room and bedrooms (sockets and lights) should have normal power for 48hrs without any mains or solar input.

 

I'm currently planning on leaving the kitchen, showers and air-con powered by the grid.

In a pinch we can survive with the gas hob and fans for the rooms.

It all sounds like Welsh to me - but I would like to have my computer keep running... the power is never off for too long.. 

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When you build your final pack ensure you clean up the battery terminals and bus-bars (sandpaper well), you need to minimise the contact resistance.

 

I'd also recommend the use of an electrical jointing compound to minimise resistance and prevent corrosion https://www.lazada.co.th/products/i2156648662-s7185722295.html it's not cheap but one tube should last forever, you don't need much.

 

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12 minutes ago, Crossy said:

When you build your final pack ensure you clean up the battery terminals and bus-bars (sandpaper well), you need to minimise the contact resistance.

 

I'd also recommend the use of an electrical jointing compound to minimise resistance and prevent corrosion https://www.lazada.co.th/products/i2156648662-s7185722295.html it's not cheap but one tube should last forever, you don't need much.

 

Yes, I encountered that problem yesterday, when I started my test the BMS reported one cell always lower than the rest,  and the copper terminal was warm to the touch. The bolt was a bit loose, another 1/2 turn and it cooled down at the same voltage as the other 3 cells. When the new cells arrived earlier I sanded down all the terminals and bus-bars. All shiny now!

IMG_20220213_170151.jpg

Edited by BritManToo
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4 minutes ago, FlorC said:

Have you checked the claim it is a pure sine inverter ?

Maybe I don't know enough of electronics , but going from DC to an AC sine , must have some serious dissipation loss.

 

Modern high-frequency inverters are well into the upper 90%s efficiency even "pure sine" which are really still digital synthesised sine, but the chop frequency is in the hundreds of kHz with output filtering so anything attached doesn't notice.

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6 minutes ago, FlorC said:

Must be quite some big filter to filter high frequencies out of an inverter that delivers 10's of amps at 230 V.

 

Yup, some very fat wires on pretty meaty ferrite torroids in there. The inverters we use on railway systems are significantly larger than anything with a few 10s of amps (think a few 100s of amps) and they output a very nice sine. They are also just a little bit more costly than anything we use for domestic.

 

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