AGM to Li

[cruiserxxx]

I am in the process of upgrading from AGM 300ah to Li 300AH, Sinopoly 12 off 100AH 3.5v cells.
Increasing the 12v solar panels from 750 watts to 1000 watts 4 off 250 watt 12V panels each is presently wired in parallel all wired in 8mm.
Existing Dingo 40/40 PWM controller
Installing 12v to 240V inverter 3000watts / 7000 watts intermitant https://www.ebay.com.au/itm/EDECOA-3000 ... 2749.l2649
Wired in 0 auto cable 250 amp fuse.

Questions:
1/ Put all 12 cells in parralell and charge with 3.6v 150 watt power supply https://www.ebay.com.au/itm/AU-Switch-P ... 2749.l2649

2/Wire 3 off 3.5v 100AH cells in parallel to achieve 300AH 3.5V cell banks
Then wire these 4 banks in series to achieve 300ah 12.5 volts.
Set 240 volt 300 watt power converter to 13.2 volts??? to charge.

3/Now to the controller, don't really want to change to a 70 amp MPPT controller at around $800.00 but it may be not that bad when compared to add ons I have to buy for Dingo 40/40, or is there other advantages with the Dingo and add ons.
My take which I still trying to get my head around
is I need solid state 100 amp relay, How much are these?
A shunt adapator https://www.rpc.com.au/catalog/external ... p-957.html $160.00
A Shunt but limited to 200amps which should be fine https://www.rpc.com.au/catalog/current- ... p-338.html

I would appreciated some clarification on this if all this is going work or just go out and buy a new 70 -80 amp controller ??
But that is still going to involve a shunt to measure SOC as want to keep the 00 cables from battery to inverter under 1.2 meters.

[BruceS]

T1 (Terry) will be along shortly but No2 sounds about right for configuration.
Watching and controlling each bank of cells is the important bit.
Terry has mastered it as perfectly as any other one I know of.
VERY important to not go under 2.9V or over 3.6V is the challenge.
You need a couple of secondary fail safes just in case!!

[dapope]

Good onya for coming over to where the good oil is

[BobnBev]

Hi That's a step in the right direction , BUT don't wast your money on the little SM supply Question 1.. Get a good charger around 50 amps . I have a pro marine 12/50 programmable , works real well. And go slow , its less costly...
Bob...

[T1 Terry]

Why Sinopoly cells? Have you already bought them? None of the LiFe chemistry cells are 3.5v nom. they are 3.2v nom. but that is really here nor there, just helps save confusion in thinking one brand is better than another.

OK, using the cells in parallel method of charging is one way to do it, but remember you must not charge the cells unless they are strapped to prevent them swelling in the middle. Don't believe the nonsense about them not swelling unless they are over charged, they will swell just sitting in the crate if not well packaged, that is why Sinopoly cells come strapped in packs of 4 with aluminium plate each end, then they are packed 2 sets a piece into a solid box, and this is just for transport. Even this is not really enough and this can be verified by running a straight edge diagonally across the aluminium end plate .... you will see what I mean if you do.
We use 3mm or 4mm end plates and strap them with 6 stainless straps anchored into each end plate. With the 200Ah cell we also roll the top and bottom of the end plate to create a 30mm wide flange to add to the rigidity of the end plates after having the flat one bulge on us during testing. Cell bulging has a direct effect on capacity, all to do with the small amount of electrolyte in each cell and the bulging allows the plates to increase the gap between each other and the liner that separates them. If the gap increases there is not enough electrolyte to bridge the gap, without the electrolyte coming into contact with both plates the lithium ion exchange can not occur, no exchange, no charging or discharging in that area of the plate. As the active area of each plate decreases so does the capacity and so does the internal resistance leading to localised heat build up and this is the real cell killer. Heat of the electrolyte is critical, stay within the safe voltage ranges for each cell and keep them tightly compressed and the cell temps will look after themselves.

There is a bit more to condition charging the cells for house battery use than just an initial charge to 3.6v but I/m not willing to share that info even here, cost me way too many $$ in hands on testing to give away that sort of information to any of the lithium battery seller that have popped up recently, let them do their own research and spend their own $$.

The next bit you need to add to your battery management system is a method of monitoring the cell voltages and stopping the charging if a cell goes over 3.6v while in service and cut the load if a cell goes below 2.8v. This step is only necessary if you want to get more than a few yrs without loosing capacity and the cells suffering increased internal resistance. Many/just about all of the recently popped up lithium battery sellers do not follow this practice, but then they probably don't care either, after all they don't warranty lost capacity or increased internal resistance do they

Probably not the answer you were hoping for, but please understand why I've been forced to take this stance, I really can't afford not too much as I'd love to share all the info for free I also need my wife to pay the rent and keep feeding me

T1 Terry

[Mrcoolabah1au]

good talk mate know what you mean have been using the new air con on must day now just the keep think normal

[cruiserxxx]

Why Sinopoly cells? Have you already bought them? I'd love to share all the info for free I also need my wife to pay the rent and keep feeding me

T1 Terry

Recieved them a couple days from China package different to the way you described.
Price good aaprox $US50.00 per 100ah cell 3.2V cell inc 6 day door to door $US84.00

Will get my son (apprentice boiler maker) to make the end plates you describe, thankyou

[Barboots]

Recieved them a couple days from China package different to the way you described.
Price good aaprox $US50.00 per 100ah cell 3.2V cell inc 6 day door to door $US84.00

Could you post a link to that supplier please mate?

Cheers, Steve

[cruiserxxx]

Recieved them a couple days from China package different to the way you described.
Price good aaprox $US50.00 per 100ah cell 3.2V cell inc 6 day door to door $US84.00

Could you post a link to that supplier please mate?

Cheers, Steve

100ah and 200ah are same chemistry .

1. Dimension for 200ah is 70*181*281mm, Gross weight is 6kg

2. Dimension for 100ah is 43*256*168mm,Gross weight is 3kg

I attached the photo and specification.

Quote: 12pcs LiFePo4 100ah 3.2v cell
unit price is 52.0USD(with copper conenctor and screw)
Shipping fee is 398.0USD

Lily.xiang
Lily_xiang <lily-victpower@victpower.com>
Oversea sales manager
Certificated: ISO9001 ISO14001
Quality goal: To satisfy customer,to build trust.
Factory address: 5F,B building, Xinmu Lowcarbon Industrial,Longgang,Pinghu,Shenzhen,China 518111
M/whatapp/wechat:+86 13632912605
QQ： 2355570369,Skype: donglin.xiang
Company name: ShenZhen Victpower Technology CO.,Ltd

[Barboots]

http://victpower.com/en/list.asp?classid=198

Not much info on storage batteries there. How did you find them... was it through Ali or similar?