AESC / LEAF Battery Modules Voltage Check

Here is a voltage check of each half module of my 3 module pack after 3 months of charge + discharge: they are still all in balance, here at the bottom at 3.59V

AESC / LEAF Battery Modules Voltage Check

After a little month of charging and discharging these 3 AESC modules wires in series, the half modules - and modules too - are perfectly in balance ...  No BMS required at all ... Like for LiFePO4 ...

Making a Charge Controller for the LEAF Battery Modules

During this week I stared building a Charge Controller for my AESC / LEAF Battery Modules
I have had this idea since last summer: build a simple, effective and safe Charge Controller for LiFePO4 cells, which is in fact a sub-system of my DIY ESS, taking care of the Battery pack charge and discharge functionality

Since the AESC Modules behave like LiFePO4, except for the voltage limits, this kind of controller ill work fine

It is composed of a Programmable Dual Relay Voltmeter, and 2 Tyco Kilovac Contactors, wires, and that's pretty much it !

I even had to read again the DIY ESS Kit documentation to see the wiring of the Voltmeter


and go through their manual to set up some additional values like the decimal point here



and I decided to set up the low voltage limit to : 3.6V x 6 half modules = 21.6V
and the high voltage limit to : 4.15V x 6 half modules = 24.9V (slightly under charge is always safer, since 4.2V is the target voltage on these Lithium Manganese cells)


Higher limit reached => the upper LED is lit and the high relay is open, which will open remove the power from the Charge Tyco Kilovac and stop the Charge .... so simple and effective


Tyco Kilovac not wired yet, but will be done later


and it should stay open until the value I entred is reached, I think it is 23.5V

The LEAF Modules based Vectrix conversion to Lithium continues ...

Last night, I got an update of the conversion work carried by Soyouz76, from the famous French Vectrix forum Vectrix.fr



Few weeks ago he announced that he found out the perfect match in width and thickness of the AESC / LEAF battery modules to fit in the original Vectrix battery compartment



He now has finished wiring the 19 modules in series and is still working on charger software updates, even if I think there is no need for it; Also he wants to get install a voltmeter kind of gage to follow the modules' individual voltage and mentioned EVtv; Here again I think this is not necessary, because with a good Bottom Balancing, only the Pack voltage has to be monitored and I proved it with my series of test on these LEAF modules


Anyways, this conversion is very promising, keep on the good work ! 

LEAF Battery Modules First Discharge through a Grid Tie Inverter

After Charging these 3 AESC or Nissan LEAF BAttery Modules up to 4V per half module, I now discharge them down to 3.6V

No BMS, just a good Bottom Balancing ....

LEAF Battery Modules Charging for the First Time after Bottom Balancing

After Bottom Balancing my New LEAF Battery Modules for a week, I started Charging them using a small 100W LiFePO4 charger

Brand new LiFePO4 24V Charger, exact same one that I use in my DIY ESS

Stripped charger leads



Bottom Balanced at 3.00V with my bottom balancer, showing 3.01 with my voltmeter here, but what's important is that all the half modules are at the same voltage

Charging begins ...



Low wattage at the beginning of the charge because the battery pack is 18V


I am monitoring the voltage of all half modules during the charge process, and they are always going up together


Going up ...

here at 4V,  but I finally ended the charge process after 13h (more or less) and half module voltage of 4.01V, pack voltage of 24,06V


The funny thing is that, on sunday I watched EVtv latest episode, and Jack was showing his testing of charge and discharge on the same modules - from the Renault Fluence Better Place liquidation -

DIY ESS - One Year After Voltage Check

I have been using these 8 CALB CA180FI LiFePO4 cells over the last year with No BMS and they are still perfectly in balance ! They have been Bottom Balanced once and slightly under charged. Nothing more :-)

http://www.diyesskit.com




Special thanks to Clement for filming his dad's stuff 

LiFePO4 Charge Controller - New Enclosure, fits 2 Kilovacs and a Voltmeter & More items in stock for the DIYE SS

Last week end, I got a new waterproof enclosure for the my new DIY LiFePO4 Charge Controller Project



With this new waterproof electric junction box, higher, I can fit the 2 Tyco Kilovac  EV200AAANA Contactor, the digital programmable Voltmeter, and maybe few diodes ...




More stuff I got for the DIY ESS Kit #2 : AC breakers both for Europe, and US



More AC twin breaker enclosures for the Kit are in stock now; I have almost everything need for 5 complete DIY ESS Kit #2 Control Boards


I had also received some more smaller diodes for my next LiFePO4 Charge Controller project, and my dad measured them with me ....


Some of them were only working on one side, so not at all ... (defective ?)


I got this lot of 6 from Portugal for very low price, so it does not matter too much, just trying things for now; Here is the specification for this



I ordered it because it looked like what Jack Rickard is adding on top of the DC-DC Converters he is selling in his online store

New - Bottom Balancer Rental : 19.90€ / week - Why buy and own one when you need it only once ?

After building my DIY ESS, I realized that my DIY Bottom Balancer was not being used anymore; Of course, Bottom Balancing of individual LiFePO4 cells has to be performed only once before connecting the cells into the desired voltage string for use - before the first charge actually -

Same thing, if you want to build an ESS, convert your Vectrix from NiMH to LiFePO4 - many do that themselves -, or any other LiFePO4 based project, you will need to go through this step - see why below -





You will do the Bottom Balancing of all your cells and then, never gain ... So why buy and own an expensive piece of equipment for nothing ?

That is why I decided to provide a new service: The Bottom Balancer Rental, for 19.90€ / week, excluding shipping period, so you have a full week of use of it, plenty of time to empty your cells, then return the device to me


Why is Bottom Balancing mandatory ?

Read : LiFePO4 Battery Charging Method - Don't Ruin your Expensive Cells !


Bottom Balancing the DIY ESS CALB CA180FI Cells

Bottom Balancer video



Does it work ?

Yes, I have used this device on 3 different LiFePO4 Battery packs, with 2 different cells brands



How do I use it ?

I will provide a PDF documentation by email to the persons renting it



Interested ?

Start renting my Bottom Balancer Now:

Options

1 Week - €19,90 EUR 2 Weeks (20% off) - €31,90 EUR 3 Weeks (30% off) - €41,90 EUR

NB: Shipping costs not included

NB: To prevent problems, I will charge an extra 100 EUR as a security deposit, refunded when the Bottom Balancer comes back to me

Watching the LiFePO4 DIY ESS Charge all day at home, from work, and back home

When my LiFePO4 DIY ESS battery pack is depleted, at 24V, the programmable voltmeter's low limit relay opens, the contactor opens, and the Grid Tie Inverter mode is shut off (low red led ON); This is what happended here

Immediately, the pack voltage goes back up and settles down around 25.4V

Now in the morning, for testing purposes, I siwthed the ESS to Forced Charge Mode, and all the chargers then are charging the battery pack

Since I can not stay all day next to it, I usually leave Karotz watch it for me and take a look remotely from time to time while away from home

08:20

At work 

10:07

11:31

16:34

it then continues and goes up pretty quickly after 27.5V to 28V where the upper limit voltage is reached and the programmable voltmeter opens its other relay, opening the charger side contactor, and terminating the charge completely

and the total Enegry used to charge fully the pack is 5kWh