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

[BritManToo]

Finished now.

Was all easier than expected, apart from drilling the holes for the solar panels.

Producing just under 1500W at midday today from 7x 330W solar panels.

One item still to arrive and fit ..... power meter from China @280bht. 

 

[BritManToo]

No way to measure the OP from the inverter ..... only a naff graph, so I've just added a power meter.

7 panels isn't giving me enough to ensure a fully charged battery, so I've another one coming.

 

[BritManToo]

So at the problem solving stage .........

Battery has one cell that drops to 2.5V (BMS cut-off) when the other 15 cells are still at 3V.

Thought I'd try an active balancer ..... 850bht, 2A max balance to try and even things out.

So the balancer has an LED to show when each cell is being balanced.

After the batteries are charged ....... no LEDs are on as the cells are within 0.010V of each other.

When the batteries are empty ....... 6 LEDS on, as some cells are O.350V different.

Sort of works, but the LEDs lock on and the board is hot.

6 hours later the LEDs are still locked on, the cells are back to 0.010v difference, and the board is still HOT.

 

Only way to get the LEDs off is to pull the plug, and reconnect.

After investigating on the net (Youtube) it seems the consensus is the active balancers are worthless.

Mine is going in the bin, nothing else in my system gets hot apart from this piece of junk.

 

Now ordered 2 more cells, hopefully one of the two will not discharge quickly like my 'bad cell No. 14' does.

 

Overall my experience with the second hand CALB cells is unsatisfactory.

Now I can monitor my energy usage it appears the 200AH @48V battery only actually stores 5.5kWhr of usable energy, which is way below the 8-9kWhr I wanted from them.

[Muhendis]

27 minutes ago, BritManToo said:

So at the problem solving stage .........

Battery has one cell that drops to 2.5V (BMS cut-off) when the other 15 cells are still at 3V.

Thought I'd try an active balancer ..... 850bht, 2A max balance to try and even things out.

So the balancer has an LED to show when each cell is being balanced.

After the batteries are charged ....... no LEDs are on as the cells are within 0.010V of each other.

When the batteries are empty ....... 6 LEDS on, as some cells are O.350V different.

Sort of works, but the LEDs lock on and the board is hot.

6 hours later the LEDs are still locked on, the cells are back to 0.010v difference, and the board is still HOT.

 

Only way to get the LEDs off is to pull the plug, and reconnect.

After investigating on the net (Youtube) it seems the consensus is the active balancers are worthless.

Mine is going in the bin, nothing else in my system gets hot apart from this piece of junk.

 

Now ordered 2 more cells, hopefully one of the two will not discharge quickly like my 'bad cell No. 14' does.

 

Overall my experience with the second hand CALB cells is unsatisfactory.

Now I can monitor my energy usage it appears the 200AH @48V battery only actually stores 5.5kWhr of usable energy, which is way below the 8-9kWhr I wanted from them.

Can you post the link for supplier of this balancer please. and maybe post a picture of the flip side.

[Muhendis]

That balancer in the picture does not look like an active balancer and your description of it getting hot is what one would expect of a power dumping balancer.

 

The power dumping balancer works by bleeding off power from good cells into the ones which haven't quite got enough yet. It uses bypass resistors to do it and they get hot. This method is horribly inefficient.

 

The active balancer uses either inductors or capacitors to switch between cells transferring energy as needed. Capacitors are the norm because they are cheaper. Sometimes referred to as swinging capacitor balancer. A good cell will charge up a capacitor which charge is then connected to a lower voltage cell. This is done by switching transistors and is very efficient. There is very little heat and it works during both battery charge and discharge cycles. 

 

There is a bit more to it than that but I have outlined the basic idea.

[BritManToo]

27 minutes ago, Muhendis said:

Can you post the link for supplier of this balancer please. and maybe post a picture of the flip side.

From Shopee, there's only 3 active balancers on sale, 1.2a, 2a, and 5a. The 5a is totally slammed by the young battery builder on Youtube. 

[Muhendis]

34 minutes ago, BritManToo said:

The 5a is totally slammed by the young battery builder on Youtube. 

I'm not surprised.

The word "Active" on the pcb would get Shopee banned in the UK. That's the method used by many BMS manufacturers and, although I refer to it as power dump it is actually passive balancing. The resistors are permanently connected which is why they get hot and why they add a bit more drain to the batteries. As you've seen, they do work but........

[Muhendis]

This is really the sort of thing you should be looking at.

https://www.aliexpress.com/item/1005003132170432.html?spm=a2g0o.productlist.0.0.3b8778b6EAJNAR&algo_pvid=68e99c28-5cf9-4b87-a122-f1c51fc6d59b&algo_exp_id=68e99c28-5cf9-4b87-a122-f1c51fc6d59b-6&pdp_ext_f={"sku_id"%3A"12000024275915775"}&pdp_pi=-1%3B1526.48%3B-1%3B-1%40salePrice%3BTHB%3Bsearch-mainSearch

[Crossy]

By far the best type of active balance would be the "flying-capacitor" kind, these can move charge between any pair of cells rather than just dumping it. This can compensate for a "weak" cell at least partially. With used / unknown cells well worth the $$$.

 

I have one of these on my larger pack, seems to work well. https://www.lazada.co.th//products/i2547693090-s9060712387.html

 

 

[Crossy]

2 hours ago, BritManToo said:

Overall my experience with the second hand CALB cells is unsatisfactory.

Now I can monitor my energy usage it appears the 200AH @48V battery only actually stores 5.5kWhr of usable energy, which is way below the 8-9kWhr I wanted from them.

 

Yeah, that's only about 100Ah's worth, but you do seem to have an iffy cell in that pack which is well worth replacing. With only a passive balancer that cell won't be compensated for ???? 

 

Which seller did you use??

 

Mine were from lifepo4shop on Lazada. 

 

We're getting about 11kWh from 200Ah of the CALB cells + 100Ah of "unknown" cells (which we know are only 50Ah)

[BritManToo]

It's been 8 days running now, I've been generating 7kWhr and using 8kWhr/day (from 7x 320w solar cells + grid) on my lights/sockets/entertainment. (excluding cooking/Aircon/showers/washing mc)

 

Bit of a gap between 5am (battery runs out) and 9am (solar cells generating).

I need a bit more battery, and two more solar cells before I'm satisfied.

 

Thinking of buying another 16 s/h cells and making my battery 16s2p to double my storage without buying another BMS .......... but that would cost another 24Kbht (Sinopoly) which is a tad expensive. Thinking of buying another 2 x 345w solar cells 7,100bht.

 

The 14kbht inverter works very well so far, a bit lacking in the data reporting, but 100% in doing the job. Glad I bought cheap, I didn't have any of the problems that the expensive equipment buyers keep reporting.

2 more CALB cells arriving today, to replace the 1 duff cell I have.

Spend so far Inverter 13k5, batteries 34k, solar cells 22k = 70k

Extra spend I'm trying to justify solar cells (2) 7k1, batteries (14) 21k.

 

[BritManToo]

Bad cell now replaced.

[Crossy]

2 hours ago, BritManToo said:

Bad cell now replaced.

 

Did you buy another or actually get a replacement from the seller??

 

Let us know how much improvement in capacity you get. 

[BritManToo]

1 hour ago, Crossy said:

Did you buy another or actually get a replacement from the seller??

Let us know how much improvement in capacity you get. 

Bought 2 from a different seller for 3030bht delivered.

[Pink7]

Im happy to see your project progress and your inverter doing well. Im considering getting 2 of this inverter in parallel.

 

Pink

[BritManToo]

Almost done ...... 9 panels about 3000w of solar, currently producing 1740w at 11:30am on a sunny day.

3 panels bolted down, 2 panels with holes ready to bolt down, 4 just laying on the rails.

All wired up and producing.

 

Too tired to continue ......... hoping for no high winds in the next couple of days.

 

[Adumbration]

On 2/19/2022 at 1:56 PM, Kinnock said:

A UPS may be a simpler option if you only want to keep your computer running during brief power cuts?

I have gone through a number of UPS different brands and styles.  Not happy with any of them.  Also not happy with the 9ah battery size.  I found a seller on shopee that sells second hand Syndome units for only 750baht (no battery).

 

I wired it to a new 12v car battery (1400baht).

 

The UPS sits next to my computer but the car battery is out of the way on the floor in the corner.

 

I have no idea how long it could run my desktop for.  Don't have many outages here.

 

Had one for 4 hours a few months back (car hit power pole) and ran computer fine for the duration.

 

I should also mention that when I go out fishing at night I take the UPS battery with me to power the lights on my fishing boat.  And then just connect back to the UPS the next morning.  It is not a huge battery, about the size in a Vios.  Runs my boat lights, GPS and fish sounder all night with no worries also.

[FlorC]

So 1740 W from 9 x 350W panels at midday in sunny thailand ?
I wonder how they will ever deliver the promised 350.
You bought polycrystalline , would mono be better ?
Why do some of your panels look different ?

Please give a link to the latest battery buy of 3030B.

[BritManToo]

16 minutes ago, FlorC said:

Please give a link to the latest battery buy of 3030B.

This guy is doing the best deal at the moment, 4x 100AH LifePo4 batteries for 3,100bht + 200bht post.

https://www.facebook.com/groups/595023491452031/user/100001625929592/

 

or Lazada

https://www.lazada.co.th/products/battery-lithium-life-pro4-100a-32v-sinopoly-diy-i1945022429-s6165348967.html

 

I wouldn't buy the S/H CALB 200AH batteries again, only getting 6kWhr out of 16s in a 48V pack (25000bht) ....... just not good enough.

[BritManToo]

28 minutes ago, FlorC said:

Why do some of your panels look different ?

'Cos they are different ............

4x BlueTech 345w, 3x XinJing 330w, 2x SunPoly 330w

Impossible to buy matching Solar panels unless you buy them all in 1 order.

[BritManToo]

The good news this month, now I've been mainly off grid for the past 3 weeks .......

1 week with 7 panels, no battery (wasting the excess)

2 weeks with 7 panels + batteries (couldn't fully charge the batteries)

1 week with 9 panels + batteries (full charge + a little waste)

My total PEA electricity bill ...... 95units ....... 372Bht

(down from 1500bht before solar in the same month 2 years back).

 

(the 3 months before going mainly off grid, I was using 170-180 units/month)

[Eff1n2ret]

1 hour ago, FlorC said:

So 1740 W from 9 x 350W panels at midday in sunny thailand ?

Agreed, that's not impressive. Just coming up to one year's use of my system, 7 x 405w monocrystalline panels with 3 kw inverter, a couple of times the readings spiked above 3Kw, this month the better days show 2.3 - 2.4kw peak, 8-hour totals up to 14Kwh (I take readings at 9am and 5pm). In January I often got 15 - 16Kwh.

[Crossy]

Our 10.1kWP (all poly panels) peaks out at around 8.5kW at the inverter output. That same day generated 41.7kWh.

 

I'm definitely not unhappy, the panels are not perfectly angled (on the car port roof).

 

[Crossy]

2 hours ago, BritManToo said:

I wouldn't buy the S/H CALB 200AH batteries again, only getting 6kWhr out of 16s in a 48V pack (25000bht) ....... just not good enough.

 

Yeah, we are doing at least 50% better than that from similar used golf-cart cells. How is the cell balance?

[BritManToo]

4 minutes ago, Crossy said:

 

Yeah, we are doing at least 50% better than that from similar used golf-cart cells. How is the cell balance?

That's not really a problem now I've replaced 2 cells. 

 

The pv output is around the same as @Eff1n2ret, couple of days hit 2.5 then the smog moved in and down to 1.75kW

[BritManToo]

Decided I need some more battery storage.

Another 16x 100ah batteries, Sinopoly green 100ah

Ordered 8x from Lazada at 714bht+40bht post = 6032bht COD

Ordered 8x from a LifePo4 Facebook group at 690bht free post = 5520bht (bank transfer)

Ordered 150A Daly BMS (bluetooth + power bar) TJ Solar = 3464bht COD

That should give me another 4kWhr of storage, totalling 10kWhr.

Let's hope they turn up (and work).

 

Thought about buying the Jikong (8s-20s) 150A BMS, but it was 100bht more than the Daly, didn't have connectors on the power cables, and needed a 9v battery to turn on, so I stuck with the Daly which is very easy to use.

[scorecard]

On 2/5/2022 at 12:53 PM, Crossy said:

 

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.

 

Crossy, what's your opinion please, and other members too, about these types of items:

 

[BritManToo]

1 hour ago, scorecard said:

Crossy, what's your opinion please, and other members too, about these types of items:

Worthless junk!

[Crossy]

7 hours ago, scorecard said:

Crossy, what's your opinion please, and other members too, about these types of items:

 

I agree with @BritManToo, junk which actually achieves nothing.

 

Not the exact same unit, but they all look very similar inside.

 

 

[Muhendis]

Like the man said.

Rubbish.

Power factor correction changes with each different load. There is no such thing as one size fits all.

Another video.