New to lithium batteries

[XO4001]

Hi All,

New to this forum.

Need the expertise from the members since I’m new to lithium batteries.

I have a SolarEdge system running with 13 KW panels and a 10KW inverter with zero feedback to the grid.

Want to do a change with battery backup and thinking of building my own batteries.

My goal is 40KWh backup in batteries that would be 4 sets of 16s at 200Amp or bigger maybe 280Amp.

Thinking of starting with 1 Goodwe hybrid inverter 5KW and if all go well then add another one.

Any do’s or don’ts or comments would be appreciated.

 

[Frank in Thailand]

First of all, why change your winning team?

Your current setup works great?
So why add additional inverter??

Second step, yes, LiFePO4 cells from Alibaba are great (B grade)
Don't expect to find A grade over there.

That's OK.
B grade is good for solar, less good for EV as that have high discharge.

48 or 72 cells, S16 (series) setup.
You can make 2 or 4 separate battery, or one big one.

I would say the last one is best.
Your cells will have slightly different internal resistance that will have impact on the whole battery.

With an internal resistance meter like the yr1035+ you can test.

My 280's are 0.15 to 0.18 Mili ohms.
Most are 0.17.
Mix and match to have on average the same in each parallel set.
With 3 or 4 cells it's easy to do.

Depending on your setup you can use the provided bus-bar or make your own.

I did, and used copper.
If I need to do it again I would choose aluminium. The terminals are aluminium and to avoid galvanic corrosion, it's best to keep the metal the same in location that is difficult to to maintenance.

Do not use the screws/bolts they provide.
Use threaded rods/headless bolts, preferably 304 stainless steel.

When you place /twist them in, you will feel some wiggle space.
I like to use Locking agent like Loctite.
Mind you, when it's in, and dry, it will not go out.
Your headless bolts need to be long enough for your usage (bus-bar , double bus-bar, perhaps even tripple?)

BMS, use one based on contactor.
Like the Chargery, DIYBMS or this one.

That is about it!

For your cells, they need to be clamped together.
A simple sheet of plywood and long treated rods would do just fine.


This is to prevent delamination or bloating.
The thin aluminium walls give Minimal strength. It does not have to be crazy, just a snug fit is good.

That is about it.
The rest is for the others

 

[XO4001]

First of all, why change your winning team?

Many thanks for your pointers really appreciate them.
The system from SE is operating well most of the time but giving me trouble that cannot be solved by SE I have 2 inverters from RMA 1 dead on arrival and the other one need some serious tweaking by SE still running the original one installed 4 years ago
Im living on an Island where the power is expensive $0.35 KWh.
Since my nightload is heavy (ac) I see an opportunity for batteries and also when we have a power failure from the grid I have a 5KWh backup from the new to install Hybrid inverter

Your current setup works great?
So why add additional inverter??

Second step, yes, LiFePO4 cells from Alibaba are great (B grade)
Don't expect to find A grade over there.

I see the prices from $80 to $120 for grade ''A'' so you are saying that they all are the same B quality then it an easy decision.

That's OK.
B grade is good for solar, less good for EV as that have high discharge.

48 or 72 cells, S16 (series) setup.
You can make 2 or 4 separate battery, or one big one.

I would say the last one is best.
Your cells will have slightly different internal resistance that will have impact on the whole battery

I feel like make 4 separate ones if a cell goes bad then take that one out and I have 15 spare ones.
also the handling and storage would be quite challenging as 1 pack.

.

With an internal resistance meter like the yr1035+ you can test.

Thanks will look into that.

My 280's are 0.15 to 0.18 Mili ohms.
Most are 0.17.
Mix and match to have on average the same in each parallel set.
With 3 or 4 cells it's easy to do.

Depending on your setup you can use the provided bus-bar or make your own.

I did, and used copper.
If I need to do it again I would choose aluminium. The terminals are aluminium and to avoid galvanic corrosion, it's best to keep the metal the same in location that is difficult to to maintenance.

Do not use the screws/bolts they provide.
Use threaded rods/headless bolts, preferably 304 stainless steel.

When you place /twist them in, you will feel some wiggle space.
I like to use Locking agent like Loctite.
Mind you, when it's in, and dry, it will not go out.
Your headless bolts need to be long enough for your usage (bus-bar , double bus-bar, perhaps even tripple?)

BMS, use one based on contactor.
Like the Chargery, DIYBMS or this one.

The this one link is not working I looked at the chargery and looks nice
If I'm planning to charge and discharge with max 100 Amp can i take the 100 Amp shunt or would it be better to go with the 300 Amp

That is about it!

For your cells, they need to be clamped together.
A simple sheet of plywood and long treated rods would do just fine.
View attachment 37634View attachment 37635

This is to prevent delamination or bloating.
The thin aluminium walls give Minimal strength. It does not have to be crazy, just a snug fit is good.

Is it advisable to put an insulator between the cells like a piece of plexi or alike?

That is about it.
The rest is for the others

Thanks again.

 

[Frank in Thailand]

No insulator between the cells.

Here is the link again
I hope it works now.

If one cell would fail, you can downgrade the pack from S16 to S15, still 48v compatible.
That way you lose 1 bad and have 3 spare.
Plus, the mix and match makes it more stable.

Also, you safe the costs for 4 X BMS

For the cells,
I made some time ago a post for the different sellers
Information might be a little outdated but the price didn't change much.

Information still relevant.

Yes, all grade B.
But.. some sellers have better packaging or better matching for internal resistance.
Xuba provides the best insight in the process, but is with it more expensive. (15-20%)
Their transport pricing is often not so good.

Lishen 272 Ah seem to be really good, if you can't find 280 Eve's.

 

[jtvt]

No insulator between the cells.

Here is the link again
I hope it works now.

I ordered a couple of those. Likely as a stop gap. I'm wondering about inrush on those. I was thinking maybe one could patch in a rec precharge on those.

 

[Golferpaul]

I just put in a Relion 12 volt 100ah Lithium Ion battery on my travel trailer. I have a 2018 Chevy Silverado 2500HD. Will this charge my lithium battery? Won't be any problems? Thanks for any input.

 

[Frank in Thailand]

I ordered a couple of those. Likely as a stop gap. I'm wondering about inrush on those. I was thinking maybe one could patch in a rec precharge on those.

English please
I can't understand what you are trying to say here.

 

[Frank in Thailand]

I just put in a Relion 12 volt 100ah Lithium Ion battery on my travel trailer. I have a 2018 Chevy Silverado 2500HD. Will this charge my lithium battery? Won't be any problems? Thanks for any input.

Please open your own thread,
No hijacking!

If the LiFePO4 battery has a BMS, it can be possible.

 

[XO4001]

Here is the link again
I hope it works now.

Yes it works now, are you Dutch by any change (I am) because the explanation come in Dutch.
Read your post about the purchasing cells very informative thanks.
Yesterday evening a couple doors down a house in our street went up in flames (reason unknown )now the wife is scared for the batteries to catch fire lifepo is pretty safe right?
If I decide to build 4p16s there would no monitoring of each cell what would happening when 1 or 2 go bad or run?
As always appreciate your feedback.

 

[Frank in Thailand]

Yes, I'm form Holland originally.
Now live in Thailand.
The link opens for me in Thai .
AliExpress doesn't keep the language settings in the link.

LiFePO4 is absurd safe.
It's been thrown in fire, shot at, full short, dropped from a building etc.

Really Nice YouTube video's
Not hard to find.

If you don't use BMS to monitor, the cells will go out of balance.
That will mean that one cell is high and the others lower.

You keep charging till "full" and overcharge the high cell.

As result that one goes damaged and performs less.
As result the other cells will overcharge and also perform less

Up to the point where it's all dead.

You don't need to monitor, that what a BMS is for.

Lithium polymer like in E-bike.they are not safe.
Also many funny videos on YouTube where E-bike catch fire.

LiFePO4.. is safe.

Just show her both videos

 

[Frank in Thailand]

This link is for S13 to S20, not for 24v

This one can do S7

139.0US $ |smart 200A BMS 7S 8S 13S 16S 20S 24S 48V 60V 72V Lifepo4 li ion Lipo Battery common port balance BMS 200A with Bluetooth APP|Battery Accessories| - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

a.aliexpress.com

So Minimal 24v.

You can read all about it here

Thread 'Anyone have this BMS?? QUCC latest model' https://diysolarforum.com/threads/anyone-have-this-bms-qucc-latest-model.17600/

 

[XO4001]

@fhorst OK Im from that country also and living the last 20 years in the Bahamas
I ment building 1 big battery 4p16s and using 1 BMS guess if I get a report of a bad cell then I have to inspect 4 correct.
Still didn't figure out what inverter to use what you are using?
The Goodwe cannot be parallel coupled looking at the Deye now.

 

[Frank in Thailand]

I'm using the Revo II from Sorotec, I bought it via Alibaba.
If you mention my name (Frank from Thailand) to Eurus or Ella, you might get some discounts.

I like it, a lot.
Only down side is that their standard lithium setting is S15...
Doesn't matter, manual battery settings work great.

I have 3 X 3.2kw, each unit can do 4.500 watt solar on max 450v.

2 of them have more panels then official supported.
One 18 X 325 (5850w) but they are not in optimal tilt, and one 16 X 345 (5520)
Both give the max the Revo can do, 5000w.
The other have 9 X 325.
3 different locations of the panels.

For energy usage, one is mostly sufficient.
We do have a large pump who likes to get +2500w at startup and 2000 when running.
Obviously, one Revo isn't happy with that, maxing out it's capacity and goes in "overload" safety.
Not due the 2500 watt, but because it already is providing +2000w...
4500 watts is too much for 3200 watt unit. For short time it can handle some extra, but the pump, together with Airconditioning, normal usage, crypto mining...
Nope ?

I have all 3 in parallel and that isn't any problem.

During setup phase I ran the house from time to time from one Revo.
(Who also got all the solar)
Still Max 5000, but longer hours that 5000

It's one or 3 phase setup (for 3 phase need minimal 3 units)
NOT split phase.

I know Victron also doesn't do split phase, but offers conversion box.

Victron is expensive.
Really expensive, but high quality products.
(And from NL)
I doubt they are more quiet then the standard hybrids...

I modified mine as they are close / in our bedroom.
Way to much noise from those 2 x 80mm fans.
Now 120mm and ducts.
Virtually silent