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Posted

Hi all,

I need to share this with you guys (and girls)
Last year I replaced my inverter with one from EASUN (NOT !! recommend) and the device that was delivered turned out to be defective and charged my 48v system with 78v.
By by my new 16 x 200Ah lead-acid... + 125.000 thb go POEF.. now 1000kg old lead.

The inverter has been returned to China and I have received new inverter, 3 x 3.2kw Revo II (I can highly recommend) (Via Alibaba)

Now the MPPT inverters are good, I need to replace the 16 x 200ah, who, while they act like fully charged, wont last 1/2 night.. (empty, some even down to 8.5v)
Yes, the lead acid are really busted, dead.

(I will try to bring them back to life with de-sulphate pulsing. that takes about 8 weeks for 200ah. If that still won't work, the Epson salt trick)


Back to Topic.
I ordered (and received) 32 x 152Ah lifepo4 cells from Haomi Electrionic Trading 
32 * 3.2V 152Ah LiFePO4 lithium batteries for $1602,- incl. DDP to Isaan
DDP = all costs paid, including tax, and delivered at my doorstep!)

Now I life remote location, we need to live off-grid as the closest electrical connection is 8km from our home.
For people more close to BKK this price even can be lower.

Yes, LiFePo4 is little more complicated then lead-acid.
It does need BMS (Battery management system)
Thrust me, it is really simple to install. (link to famous youtuber Will Prowse, he's good!)

Anyway..
They have a few special offers:
120Ah batteries for $ 37.50
152Ah batteries for $ 43,-

280Ah batteries for $ 79.80
(It is special offer, so please mention my name (Frank, from ThaiVisa)

Lifepo4 is more efficient 95% while lead-acid have 70% 
Every KW you put in there, with lead-acid 30% is lost as heat

Lifepo4 have no memort and can be used almost 100%. 
Lead acid need to stay full at-least 40% better 60% to have many cycles.
With lifepo4 you have more cycles (2000 tov lead 500), and you can use like 95% !!

5kw system need 600Ah on 24 volt to really deliver the 5KW.
that is 6 x 12v 200AH. = 50.000thb or $ 1600
lifepo4 need 8 x 280ah cells = 20.100thb or $640 (+ $300 transport) = $940,-
BMS is $120,-
total price: 1060,- (for + 6.5KW)

You probably need less time to make the installation as the heavy 70kg lead-acid would take.

This seller offers OK pricing, but you need to educate yourself by informing pricing from different transport companies as well.
A few transport companies I use for quotations: JWLogistics, QTCY (often cheapest), Bohang logistics

General information: How to order Chinese Batteries


For BMS, I ordered the  "A/2A Active Balance Battery Protection Board Smart BMS
this seller is know company for Chargery and Daly BMS, and now have developed this new type!

(on aliexpress they are called "IC GOGOGO Store" on Alibaba E&J Technology Group)

 

It is available for shipment!! 

It ain't the cheapest option, price start at $95

 

Mine, the 24S 1A 300A, is $119.28

 

I'll update you when I have received and tested.

 

bms.jpg

 

 

 

 

english app.jpg

 

 

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  • Like 1
Posted

how massive can the task become if some want to convert LiIon etc 3.7v systems over to 3.2v LiFepo4?  

 - like the already physically measured out arrays of 3.7v batteries to match the solar arrays on rooves etc 

 - imagine the logistics if one wanted to retrofit same for Tesla like vehicles 

 

 

ps I am myself all for the new LiFepo4 tech

Posted
6 hours ago, tifino said:

how massive can the task become if some want to convert LiIon etc 3.7v systems over to 3.2v LiFepo4?  

 - like the already physically measured out arrays of 3.7v batteries to match the solar arrays on rooves etc 

 - imagine the logistics if one wanted to retrofit same for Tesla like vehicles 

 

 

ps I am myself all for the new LiFepo4 tech

how massive??
all depends on the scale!!

And.. mostly the end usage.
what does the user want?
12v, 24v or 48v are the most common for solar storage.
take 24 volt, it uses 8x 3.2v (25.6) lifepo4 or 7 x 3.7v (25.9)
Lead-acid it would be 2 batteries each 12.7v = 25.4 volts

For 48 volt systems you use 15 (or 16) lifepo4 cells, Li-ion 14 cells.

Both need BMS, both need balancing (high discharge like car require more balancing, simple solar almost nothing)
Logistics to make enough power for a car...
not a problem!

good thing about lifepo4, you can use them almost like lead-acid!
4x 3.2 volt you can charge with normal lead acid charger. Not 100% , but like 90%
As it is loads and loads better then lead, you won't even notice.

with cheaper BMS you can not stack (use 2 x 4 strings (12v) to make 24 volt.
then you better buy 8 string.
Good thing is that you can parallel almost as much as you like..
that can be 10 x 120ah, to make 1.200ah string.
(personally, i would use 4 or 5 280Ah to do this)

how massive??
probably a lot less then you think!
the solar panels can stay the same, inverter, mppt, fuses, all others.
only different shape and different BMS..

Posted

all very well about the MaH rates, but for relativity; would the physical dimensions of an automotive battery, and a Bulk parallelled LiFePo4 battery assy - be of equivalent L*W*H dimensions?

 

 The MaH rates are being shown, but what of the ultimate CCA ratings of LiFePo4? 

 

Retrofitting a car, to use these instead of the big unflexible brick of an automotive battery, would enable changing the very shape of a new Cranking battery, to match the variable spaces available under the bonnet!

 - weight balances too!

Posted

CCA = cold cranking amps....
We do NOT talk about MaH, but real, full ampere.
Modern Lifepo4 have discharge rate of 2 or 3C, and charge rate of C 0.5 or 1
yes, the 200Ah battery can shoot 400 to 600 AH till empty, and recharge in 1 or 2 hours to full.

Deep cycle lead acid have C-rating of 0.05 to be able to give their stored capacity.  (20 hours discharge)
faster is possible, but you lose up to 50%

CCA = cold cranking amps...... 
that is talking about starting a car engine.

for size? LifePO4 batteries are 70% smaller and 300% lighter than lead-acid batteries
I'll make you a picture tomorrow for comparing.
I have a few old (almost dead) lead acid 125Ah and can show you 4 lifepo4 cells 152Ah besides it.
Why 4?
4 x 3.2v = 12v 
it will give you an idea ????


A starter battery is build a lot different from storage battery !!
(like a race car from a tractor)
There are lithium batteries special for extra high discharge, up to C10. (like starter battery)
(75A lead acid starter can do about 630cca, 750ca)

C3 rating 96v @ 280Ah (about 25kw/h) is 600x96 = 80kw engine. (96 volt, 32x lifepo4 seem to be often used voltage)
you can drive for 15-20 minutes full power.
80kw = 108PK
total weight is 5.2kg per cell, x 32 = about 170kg

my 12v, 200ah lead acid way 70kg each. 
to be able to give you real 80kw, you need minimal 32x200a, about 2.250kg to be able to use 15-20 minutes 108pk ????
(with starter batteries probably less, I think 750-1000kg)

I thought from your post you like to make your car electric.
then we start talking about watts, as the electo motors rating is wattage.!
Tesla P85D have 691 hp (515 kW), and 100kwh 
(4 times the batteries I 
used as example, battery pack of 700kgs is about right)
 

Posted

Here they are.

This is 152Ah compared to 125ah.

 

125ah at max 12.7v is about 1.2kw

152ah at max 14.6 (4*3.65) is about max 2kw discharge

 

 

IMG_20200310_201017.jpg

IMG_20200310_201017.jpg

IMG_20200310_201026.jpg

IMG_20200310_201049.jpg

Posted

The 125 BK is 40 * 17 and 26cm high.

 

4* 152 = 19.5 *17.5 and 16 high

(But you need to fit busbars, so count 17cm high)

One cell is about 4.6cm thick.

One cell is 2.95 kgs.

 

The 280ah are bigger and more weight ????

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