Joe,
I already suggested this to another lister, purchase 4 small 6AH LiFePO4 cells
and a decent BMS. Connect the cells in a 4S configuration along with the BMS
wires. It is a great way understand the BMS operations and run through many
charge/discharge tests.
I did this recently with 4 cells (type 32700 6AH LiFePO4) purchased from Ebay
($24). I clamped the cells together between 2 scrap pieces of starboard, and I
used some 1” wide copper braid for making the 4S battery cell connections, but
other material should work fine. I did this to test a second BMS, identical to
my first except the new one has a RS485 com port. Both have bluetooth and the
iOS app is great, but I wanted to connect the BMS to a raspberry pi for
graphing long term performance and remote monitoring.
Here are a few link:
eBay LiFePO4 cells:
https://www.ebay.com/itm/283963906954
BMS:
https://www.lithiumbatterypcb.com/product/4s-or-3s-12v-li-ion-or-lifepo4-battery-smart-bms-with-bluetooth-function-uart-and-rs485-communication-with-60a-to-120a-constant-current/
<https://www.lithiumbatterypcb.com/product/4s-or-3s-12v-li-ion-or-lifepo4-battery-smart-bms-with-bluetooth-function-uart-and-rs485-communication-with-60a-to-120a-constant-current/>
I choose the BMS options: 4S 120A Lifepo4 With UART and RS485 and I also
purchased the $7 RS485 communication module for USB connection.
You may or may not want to hack around with the RS485 and keep it simple with
just the Bluetooth interface, only a $2-3 difference. This BMS is highly
recommended from the solar DIY community, and I am very happy with its
operations.
I just threw some photos of this set up on my blog (no text). See link below.
The last photo shows the out from a simple python program which read the BMS
data via USB cable and plots the values for the past 2 hrs and 48hrs.
https://www.blogger.com/blog/post/edit/5300937164934526048/7297536651823236179?hl=en
Paul
-
Paul E.
1981 C&C Landfall 38
S/V Johanna Rose
Fort Walton Beach, FL
http://svjohannarose.blogspot.com/
Thanks to all of the subscribers that contributed to the list to help with the
costs involved. If you want to show your support to the list - use PayPal to
send contribution -- https://www.paypal.me/stumurray Thanks - Stu
