LiFePo4 charging

[buckland]

Anyone have an idea why the battery pack peaks out at 13.2 charge?
My Victron 100 20 mppt controller is set to 13.8 V for absorption

160 Watt panel in full sun doing great but battery not going over 13.2

 

[Happyjax]

Are you using a LifeP04 charging profile?

LifeP04 uses constant current charging as far as I remember. I don't believe it uses absorption.....

Others may know more.....

 

[photohc]

Yes, you should be using a lithium charge profile. According to the manual for the Victron 100/30, the profile is #7 on the rotary switch, however in review of the manual for the Victron 100/20, it doesn't offer an easy profile selection. You may be able to manually change the voltage levels to match what is required of the lithium battery you have using a pc connection.

 

[Vic Harder]

Buckland is using a LiFePo4 charging profile. He knows more than most on this forum re: these batteries.... heck, he built his own 12v battery from scratch!

And correct me if I'm wrong, but this WAS working before, right? This is a recent issue?

I just got a BattleBorn 100AH for my new PUMA build out. As a newbie to LiFePo4 I have relied on rando, Craig333, buckland, PaulT and others (sorry if I missed you) who have been pioneers in this area.

The stuff I know I also gleaned from Will Prowse - LINK, who is enthusiastic, knowledgeable and helpful. Also from Battleborn's web site on using Victron gear with their batteries - LINK and from this helpful dude -

.

I usually avoid reading comments on social media posts, but in this case there were some useful ones, and I quote:

Paul G - on Oct 29, 2017 at 10:09 AM - said: Here's a quick reference so you don't need to keep replaying the video like I did. There are only 4 changes from default (01, 02, 05 and 06) marked with a *:
01 Battery Capacity - 99AH*
02 Charged Voltage - 14.4V*
03 Tail Current - 4.0%
04 Charged Detection - 03
05 Puekert Exponent - 1.05*
06 Charge Efficiency Factor - 99%
07 Current Theshold - 0.10A
08 Time to Go Averaging Period - 03
09 Zero Current Calibration - ZERO
10 Synchronize - SYNC
11 Relay Mode - DFLT

And then Denis Phares added to this on June 2, 2018 at 4:449 PM
Try reducing your end charging current from 4% (as suggested in the video) to 1%. This will allow the batteries to be topped off in the absorption stage a little bit more. This will also allow extra time for balancing. If the charge current is high, than [sic] 4% of the charge current my be too high for the final top off.

All that said, in my BMV 712 I have my Bulk/Absorption voltage set to 14.5V with a 30 minute Absorption cycle per recommendations from Battleborn, and float set to 13.5V.

And the 100/30 MPPT controller is set as in the notes above.

I also recall rando saying something about backing off from those setting to keep the battery between 10% and 90% SOC, as LiFePo4 chemistry rewards not using the full cycle of available SOC by vastly increasing the number of discharge cycles they will tolerate. Unfortunately I don't remember the details.

Now, my Buckland isn't getting a the batteries to go beyond 13.2V.... I don't know, but hopefully something in the above info will be helpful!

 

[buckland]

Not sure if I should have used the Ultimate battery thread for this I'll continue here unless told to move.
I am perplexed. I am a novice though learning. I tend to jump into things with both feet and cause a lot of my own misery. But I have to
have a hands on approach on to grasp concepts. That is why I decided to build my own despite the fact I was learning as I went along.

On a three week trip the new built battery was doing great then suddenly 12 days in started to not charge as high and the voltage drained lower and lower until I noticed that my cells were out of balance and I shut it all down and bought ice!

After getting home I pulled the battery. I set up an inverter on the battery and and ran a crock pot to drain the battery down to 2.9 volts in lowest cell. Then used a pack of 4 resistors to drain each cell pack down to 2.85 Volts. Then I Bottom-Balanced with the battery Management gizmo to 2.9 (as there was bounce back voltage). Then I reinstalled the battery and watched it solar recharge throughout the day... a real high sun day. It charged up to and leveled off at 13.2 Volts. Nothing was running in the camper except the propane detector.

I have the Victron 100 20 smart controller with a bluetooth app. Attached find two photos of the settings page and the display. I have renolgy 160 panel.
Perhaps I should have it set up differently? Perhaps I have built a lousy battery!

Either way I am glad I attempted it for the experience. If I can't get it to work I will chalk it up and save up for a Battleborn. I am sold on LiFePo4 as the only way to go.... once I get out of the hole I'm in!

Thanks for all suggestions. BTW the BMS monitor attached to the packs shows the four cell packs as: 3.2, 3.3, 3.3, 3.3 Volts this morning.

 

[Vic Harder]

It can't hurt the battery to really top it up ... once. Try setting the bulk/absorb voltage to what Battleborn recommends for theirs... 14.4V, with a 30 min absorb cycle per 100AH, and a 13.5 Float level.

 

[buckland]

I tried this morning putting at 14V and reducing time to 30 minutes. After 8 hours of sun... it had risen to 13.45 then fell back to 13.2 at dusk. There is something amiss. Probably not the electronics but rather wiring somewhere or a drain (short)... somewhere and I hate to think where. The truck did take a lot of jolts on the trip and the battery could have been jostled (though packed well in a foam lined box) and a major wire or solder failed. This sounds like a good winter project! Not summer’s end.... so might just pull it and set it aside after draining to 11.5. For those that consider building I strongly advice you to do so. You really get a good groundwork electrical testing and that is good for a lot of camper work. If I were to start now?.... I’d do as Will does in the you tube videos .... get four cells and put them together, Boom done. Everything else is even easier. Live and learn.

 

[rando]

If you just bottom balanced your pack, then all the cells started at almost 0% SOC, so it may take more time than you think to get them back to fully charged. I don't remember your battery and solar specs - but assuming a 160W panel and a 100Ah battery, it could take 2-3 days of good sun (and more days of New England 'sun') to get 100Ah back into the battery. What does the history display in your Victron look like?

PS I would set the equalize setting on your victron to something like 14V, just in case it accidentally gets switched on - you will get a BMS shutdown at 16.2V.

 

[buckland]

I have seen a rise in voltage to 13.6 so far today. A few more hours of NE sun to go. Attached is a photo of Victron app history.

 

[buckland]

An added note. I have a Blue Seas battery separator but I do not currently have the camper plugged into the truck thinking the separator might be confused with a lead acid battery in the truck and the LiFePo4 battery in the camper connected.

 

[buckland]

For all the electric gurus .... a page to analyze ... there are some curious drastic falls in some columns ... note 26 days ago.... when my woes began.

 

[rando]

I have seen a rise in voltage to 13.6 so far today. A few more hours of NE sun to go. Attached is a photo of Victron app history.

IMG_9095.JPG

This to me would indicate that everything it working as it should - 100Ah at 13.2V is 1320Wh - over the past four days you have harvested ~1100 Wh, so you are most of the way charged. By tomorrow you should be full.

 

[buckland]

Isotherm fridge on #4 with a 12 pack of beer (hate wasting cold). Sun starting behind trees so panel V has dropped. Here is a shot of the BMS of four cells.

 

[buckland]

24 hours later ... rain all day so minimal solar... here are two shots with fridge running and then off.... maybe this will recover after all ... hope I will too!

 

[buckland]

And after fridge turned off

 

[Stokeme]

I had a crisis last Spring with my, 1.5 year old, LiFePo4 100+50Ah parallel system. My Camper was undergoing an inside shop buildout &, I don’t know how, my Batteries somehow were drained completely. 12V socket use probably. It was scary. At first they were very slow to charge from Solar. The weather was quite cloudy that week which did not help. As charging progressed it did pick up. After plugging in my portable flex panel, day 3 to add W, it really picked up. It was ~noon day 4 when the V topped up to usual. My batteries have been excellent since then.
I’ve not followed the build but I thought to question the BMS or if the cells were all the same generation. That seems to look fine. Is the Camper connected to your truck system? Here’s pics with all power off for 2 weeks. Note ... not an electric guru.

 

[buckland]

Glad you asked that question.... as I went back through history (I posted it in print form). Then I went back to the journal we keep when camping. The night that the big drop in battery occurred I had decided to check the turnbuckles and while on the floor on a instant decision I plugged the camper into the truck.
I have a Blue Sea separator... the switch turned on but the button on top not pressed in. This I believe ...had the truck and camper battery separated.
The next day the juice in my camper battery was way low.
The camper now is not attached to truck electrics. The day is partly cloudy and fridge on ... battery 13.36.

 

[Stokeme]

Followed 2 linked, long threads (honestly kind of hi jacking the latter thread) a few years back, previous to my LiFePo4 purchase. The OP was having mysterious V drain with his LFP4 Battery. He narrowed the timeline to normal V at night, abnormal & low V in the morning, that was not applicable to his amp usage. His conclusion, was the difference in resting V, between his LFP4 Camper Battery & his LA Truck Battery, was causing his Truck to drain his Camper Battery overnight, seemingly every night. I know that healthy resting V can vary between LFP4 Batteries ... configurations & generations.

 

[buckland]

That smacks of similarity!... Though being a science guy I will not assume causality until I poke around and isolate the variables. I really do think the separator is somehow responding to the truck computer system at night (I have a couple things plugged into the truck cab usb ...GPS etc... that I know at night is still on...though minimal draw) ... wonder if the truck senses and draws camper battery at night? ....
I see no reason really to keep the truck and camper connected with the solar charging my camper. But that is a statement from someone who definitely does not have all the answers! Thanks for the input.

 

[Stokeme]

X2 on being a science guy, just not an (learning) electric guy. A sincere Tip of the Hat for building a Battery.