newly commissioned Fortress eFlex 5.4 weirdness

MJSullivan56 · December 2021

I have recently commissioned a pair of Fortress eFlex 5.4 kWh batteries purchased from NAWS. Today for the first time I did a test of the new system by switching off the AC power to the inverter and letting the critical loads "run" off of the batteries only. After six hours all appears to be well with one exception: one of the batteries is showing 2 LED lights while the other is still showing 4 LEDs. The two batteries share a common pos and neg busbar (Victron Lynx). Both batteries are showing blinking "run" lights. Both are also connected via the communication cable and terminated on both ends. This behavior doesn't seem logical to me and I'm worried I might have a defective unit. Besides opening a ticket with the Fortress folks (who have yet to respond to my support request) any ideas?

BB. · December 2021

From a quick scan of the manual, it could be the one battery with 4x LEDs ON (no flashing)--That battery may not be feeding any current to your loads (all ON is resting fully charged state?). Or it may indicate 76% yp 100% state of charge while discharging...

These batteries need to go through a "configuration" process--And if not, they may not connect to the battery bus?

Do you have a good volt meter you can measure the battery terminal voltages? And do you have an AC+DC Current Clamp DMM so you can see what current is flowing to/from the two batteries?

https://www.solar-electric.com/lib/wind-sun/Fortress_eFlex_installation_manual.pdf
https://www.solar-electric.com/lib/wind-sun/eFlex-Firmware-Update-Guide.pdf

Have you contacted NAWS support yet? I do not work for them--Just help here running the forum (we are all volunteers here)--Many manufactures usually expect their distributors/retailers to provide first level customer support.

Only other thing to check (besides all connections clean and tight, no heating from poor connections or crimps) is that you wire the two batteries properly to ensure proper current sharing (equal wire resistance from chargers/loads to parallel batteries):

http://www.smartgauge.co.uk/batt_con.html

-Bill

MJSullivan56 · December 2021

The weird thing is that the two paralleled batteries individually appear to deliver the same voltage even though the LEDs suggest they are out of sync. I validated this by briefly turning off each battery and then measuring the voltage of the remaining one. Additionally, the Radian MATE3s shows the same voltage input as the batteries. So other than the LEDs the system appears to be working properly. Very odd. Oh, and after running a bit longer on battery only power, the LEDs now show batteryA=2 while batteryB=3 which proves that batteryB is in fact discharging. When I charge them back up, they both eventually go back to 4 with batteryB getting there faster.

BB. · December 2021

With a BMS, they could estimate State of Charge based on voltage--But (guessing) more likely is they do it by measuring the current flow (Amperes * Time in Hours).

Battery voltage does vary with load/charging current--Although Lithium Ion batteries have much less voltage dependence vs current than Lead Acid.

One member here had to cycle his Li Ion batteries (different brand, I think) to get the BMS values to match up to "actual" State of Charge (BMS originally reported battery empty when only 1/2 AH capacity discharge).

Anyway... You might be the expert here--Especially after working with the support engineers.

I don't want to mislead you--I am not qualified to do much more than read the manuals.

-Bill

MJSullivan56 · December 2021

Thanks for listening to my frustration. Here there appears to be a state-of-the-art LiFePO4 battery bank that I'm willing to invest in. Only to be disappointed in having to deal with "growing pains". I trust I will get there eventually. I will keep folks apprised on this thread of my progress (or lack thereof).

Cosmos · December 2021

Please keep posting your progress with the Fortress batteries. I am just finishing up a new off grid solar system using Fortress E Flex 5.4 batteries.... We can never escape the "learning curve."

MJSullivan56 · December 2021

Identified some Fortress weirdness: Using their CANBUS diagnostic tool, the pair of eFlex batteries are displaying different internal data, even though externally both the SOC LED lights as well as the individual battery voltage appear to be the same for both batteries. NOTE: both batteries have been updated to the latest firmware as shown in the screenshot. Thoughts?

Image: https://us.v-cdn.net/6024911/uploads/editor/bt/8ar6vc7y973w.jpg

MJSullivan56 · December 2021

here's what things look like at the combiner.

BB. · December 2021

From your status screen... What does this mean?

Min Cell Volt Num = 5 or 2

I would have guessed that both batteries should have the same "number" (5/2/whatever)? That would seem to be a non-trivial variance (not knowing what the heck it is).

-Bill

MJSullivan56 · December 2021

Good catch. I missed that entirely.

MJSullivan56 · December 2021

I've cycled the batteries a few times now and the SoC LEDs are now in sync. The status screens look "better" too. Even though there are obvious differences in the two (brand new) batteries, Fortress support says based on the latest reports shown below, "all looks well". So I guess I'll have to take them at their word.

newly commissioned Fortress eFlex 5.4 weirdness

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