TESTING: Lead Acid/LiFePO4 battery pack

[RogueDFW]

This is my official testing thread for my lead acid/LiFePO4 battery bank testing.

MPP Solar LV2424, wiring and testing equipment arrived. 8x3.2v 100AH Lifepo4 cells shipped from China. Two 24v Lead acid battery banks built, installation of all equipment and testing is scheduled for this weekend. Wiring schematic and pictures to follow

 

[RogueDFW]

Test setup:
1. MPP Solar LV2424 connected to shore power for testing.
2. Main 24v DC battery bank input test guage.

https://amzn.to/2EONu1m

3. Battery bank wiring combiner
4. Individual 24v battery bank test guage.

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5. Battery Bank 1:
New 24v 100AH Lifepo4 with 8s Overkill BMS with 100 Amp fuse
6. Battery Bank 2:
New 24v 100AH Lead Acid. (2*12v) with 100 Amp fuse.
7. Each LA battery has seperate voltage gauge.

All guages will be baselined to verify accuracy

Did i miss anything?

 

[Steve_S]

I run 24V, 910AH of LFP as my primary powerbank & 856AH of Rolls Surette Heavy Lead as my secondary powerbank.
They are separated using a Blue Sea 9001E switch which allows for Bank 1 or 2 or Both.
The Charge Profiles for the LFP are NOT The same as they are for FLA. The voltage cutoff points, as well as the voltage curve, don't really match up very well at all, so you will end up short-changing what you can get out of the LFP.

 

[Dannyking]

This will be an interesting test, I believe the banks will be tested separately using the same load and see how both chemistry performs. For the Fuse: which is better fuse or breaker?

 

[Abhishek Rathore]

Test setup:
1. MPP Solar LV2424 connected to shore power for testing.
2. Main 24v DC battery bank input test guage.

https://amzn.to/2EONu1m

3. Battery bank wiring combiner
4. Individual 24v battery bank test guage.

Amazon.com: bayite DC 5-120V 100A Mini Digital Current Voltage Amp Meter Ammeter Gauge with Hall Effect Sensor Transformer : Automotive

Buy bayite DC 5-120V 100A Mini Digital Current Voltage Amp Meter Ammeter Gauge with Hall Effect Sensor Transformer: Ammeters - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

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5. Battery Bank 1:
New 24v 100AH Lifepo4 with 8s Overkill BMS with 100 Amp fuse
6. Battery Bank 2:
New 24v 100AH Lead Acid. (2*12v) with 100 Amp fuse.
7. Each LA battery has seperate voltage gauge.

All guages will be baselined to verify accuracy

Did i miss anything?

Hey,

Did you really perform the test?
Please share results if you got anything useful out of it. As I can see is this inverter will not support the lithium battery bank or even if supported, it will not work at the full capacity. Please tell me if I'm wrong about it.

 

[RogueDFW]

Testing Status: Test bench has been built. Now I am awaiting on the LifoPO4 batteries to arrive. They should be delivered 25 May.

 

[Substrate]

Well, just like Battleborn's test revealing the shocking truth about the Peukert effect, you are not testing like against like, so your results will be skewed by that.

But I understand what they were trying to prove - and maybe yourself too - about how inadequate they are, especially since 99% of the population undercharges and abuses agm's in the first place. And that they need to cycle them about 5-10 times to finish the plate formation to get full rated capacity - or even a little above. Nope, most just pop them into service undercharged and under-formed. And continue abusing them for the rest of their life.

So in a real sense, Battleborns test is a "real world" test, but it raises flags for those who know.

If you wanted to get closer to a like-to-like comparison, you would test against batteries that have similarly low internal resistance (higher voltage under load).

And that means PURE-LEAD batteries. Enersys products like Odyssey on a consumer level come to mind. Wait till you price those!

Mr Peukert isn't such a meanie to these low-IR pure-lead batteries, and hammering them is part of their designed-in capability. But if you don't take care of them and charge properly - which is REALLY hard to do with solar unless you know the ropes, a test might just be proving what everyone does in real life. Not what they SHOULD do.

So I don't know if this test will reveal anything new from a real-world standpoint of how people abuse agm's in the first place.

 

[purdum]

Follwing

 

[grizzzman]

Did you give up on this project?

 

[ShedLab!]

Testing: Lead and lithium (LFP) battery banks in parallel

Will it work? What happens? How do the currents share? What do you want to know? **Note this is a controlled and supervised experiment for informational purposes only and not an endorsement to do such things** Update: Test complete. Details below in the thread.

diysolarforum.com