Valence XP Super Thread

[mitchk1303]

If the battery makes it to 13.9 it's definitely full. It doesn't need to absorb there for any amount of time because pretty much anything over 13.7 is full if it's balanced. balancing starts kicking in a little bit around 13.6 and it's definitely in full swing near 13.8. the only reason you should bring your batteries up to 13.9 is for an occasional top balance and you could probably push up to 14.1 to 14.5 during the monthly equalization considering that your batteries are not having a problem staying balanced. You could use an equalization setting to do that once a month. The batteries naturally rest at 13.4 after they're done charging but it takes a lot of hours to drop down to 13.4. But if you only charge them to 13.5 they won't absorb much amperage and will take longer to charge. If I remember correctly, it's around 13.63 when the voltage starts to fly high fast signaling it's done charging. I would hope that smart lithium chargers could take advantage of this trait.

Since they rest at 13.4 if you're floating at 13.5 they'll remain at 100% unless you draw from them because your solar can't keep up with your load in the daytime. If the voltage gets down to 13.35 in the daytime I would hope that your charger would raise it up to 13.7 briefly just to make sure they're back to charged before dropping back to 13.5. that's only really necessary if you want them to remain at 100%. otherwise you could literally float them at 13.37 and they would stay above 95%. That's probably what most people should do unless they're battery bank is overly large then they could hold them at 13.3 instead. I hope I'm not confusing you LOL anyway I got to get back to work I'll check back again in a few days.

Ok I guess I was misunderstanding then. I thought you have your absorption voltage set at 14.07V? Or is that just the max voltage you will send to the battery? I think I am misunderstanding the absorption phase. Is the voltage you select for the absorption phase the voltage the battery will be brought up to or the voltage being sent to the battery (and the battery just reaches full, not necessarily that voltage)? The absorption phase should bring the voltage of the battery right to the float voltage (13.35V).

Either way do you think I should lower the absorption voltage to 13.7V or something lower then 13.9. I also don't understand the time factor with the absorption phase. But I'm assuming if I am reaching max capacity most days I probably want a low absorption time? I can turn on adaptive absorption so on shallow discharge days the absorption time is shorter.

It sounds like I should decrease my float voltage to 13.35 in order to preserve battery life? But basically if the battery is at 13.35 it is around 95 percent full correct?

Sorry I am so scattered. I feel pretty lost as I haven't ever dealt with this stuff but I think I am starting to get a small grasp on some subjects.

 

[Travis]

Ok I guess I was misunderstanding then. I thought you have your absorption voltage set at 14.07V? Or is that just the max voltage you will send to the battery? I think I am misunderstanding the absorption phase. Is the voltage you select for the absorption phase the voltage the battery will be brought up to or the voltage being sent to the battery (and the battery just reaches full, not necessarily that voltage)? The absorption phase should bring the voltage of the battery right to the float voltage (13.35V).

Either way do you think I should lower the absorption voltage to 13.7V or something lower then 13.9. I also don't understand the time factor with the absorption phase. But I'm assuming if I am reaching max capacity most days I probably want a low absorption time? I can turn on adaptive absorption so on shallow discharge days the absorption time is shorter.

It sounds like I should decrease my float voltage to 13.35 in order to preserve battery life? But basically if the battery is at 13.35 it is around 95 percent full correct?

Sorry I am so scattered. I feel pretty lost as I haven't ever dealt with this stuff but I think I am starting to get a small grasp on some subjects.

You shouldn't lower your float voltage from the user manuals specifications unless you have more storage than you need. The thing with the absorption and float set points is the voltage will adjust battery degradation. With absorption there's no amount of time you need to stay at the voltage you choose. You simply have to reach that voltage and then you can immediately go down to float. The only time you stay in those upper voltages is during equalization

 

[mitchk1303]

Alright I think I need to choose an absorption time with the victron charge controller but I will pick the shortest amount of time and just bump that time up to a longer amount when I want to equalize the bank.

I'm more lost with the float voltage now. The valence data sheet calls out 13.8v to 14.6v. But I thought in your previous reply you said that they like a float of 13.5v and I should set it at 13.35. Once again maybe I'm confusing the float voltage being applied to the batteries vs the float voltage that the batteries are actually at. So I should set my charge controller at 13.8v float voltage but while the batteries are in float they themselves will measure somewhere around 13.5v when at 100 percent.

I think I am confused with the solar charger applied voltages vs the battery voltages. I don't think the victron allows me to set battery voltage levels for the float and absorption. Instead it allows me to set what voltages will be applied to the battery during the float and absorption stages. Maybe I'm completely off. Sorry that I'm taking a while to get this stuff.

 

[brooke_heaton]

If anyone has expertise in the quality of used Valence U27 XPs, I posted the diagnostics for mine here and am looking for feedback:

Feedback on Third Owner Valence U27-12XP Quality

Hi everyone. I'm a recent lurker working on a solar setup for an A-Frame camper. I plan to have a large battery bank for dry-docking. I purchased two Valence U27 XP's off eBay. Taking a risk, I assumed they had moderate use but the price was the best I've seen in a while so I snapped them up. I...

diysolarforum.com

 

[Perrybuilds]

Looks like Mueller Industries may have tapped out?

http://mullerindustriesusa.com/

Website went dark.

 

[mannytheseacow]

If anyone has interest in a non-working low voltage BMS (Chinese valence version) PM me.

 

[Marciano516]

I did a search and haven't been able to find any fix. I made a new Post about the issue I'm having.
Could you help?

Valence XP Battery Software Issues

I have purchased the USB 485 from amazon (https://www.amazon.com/gp/product/B077ZM1PSG/ref=ppx_yo_dt_b_asin_title_o08_s00?ie=UTF8&psc=1) updated the firmware and was able to get it working properly (well at least on the software side). On the Valence battery side I purchased these 5 pin...

diysolarforum.com

 

[brooke_heaton]

So I plan to run two U27-XPs in parallel with a Xantrex Freedom 2000 controller/inverter. How much benefit will I get from using the Thunderstruck BMS with this setup verses not? The Xantrex controller/inverter will give me high/low temp and voltage protection, but would not balance the cells. The BMS would balance the cells. Is this an issue if using in paralell?

 

[marin]

For the cells balancing only you can use the Valence software, or the open source arduino bms project linked in this thread too.

 

[Corbury]

Hi - I'm a noob here - but I have a question about XP batteries Vs. LifePo 280Ah 4s 12V setup. I'm working on a van build and I need to support a load like 1800W at 12v. That's around 150A with headroom like 200A.

option 1: EVE LifePo 280Ah 4s 12v battery with 250A Daly BMS
option 2: 138Ah Valence XP batteries x 2 (= 276Ah) with thunderstruck BMS

Thoughts on the pros and cons of the Valence option? will it support this type of load?

Thanks, C

 

[Travis]

Hi - I'm a noob here - but I have a question about XP batteries Vs. LifePo 280Ah 4s 12V setup. I'm working on a van build and I need to support a load like 1800W at 12v. That's around 150A with headroom like 200A.

option 1: EVE LifePo 280Ah 4s 12v battery with 250A Daly BMS
option 2: 138Ah Valence XP batteries x 2 (= 276Ah) with thunderstruck BMS

Thoughts on the pros and cons of the Valence option? will it support this type of load?

Thanks, C

The most I have done was 2000W from 4 valence batteries that handled it nicely. Maybe somebody else here has experience with such a small system. What's the cost comparison between your 2 options?

 

[ericgrand]

I have a set of 7 battery in my EV, connected in serie. Discharge rate are going up to 250 A, and batteries have logged a 332A peak. THey seems to hold well. So I suspect 150A continuous are not a problem...
And keep in mind batteries are usually around 13.4V, so it is 134A, just around 1C rate.

 

[Travis]

I have a set of 7 battery in my EV, connected in serie. Discharge rate are going up to 250 A, and batteries have logged a 332A peak. THey seems to hold well. So I suspect 150A continuous are not a problem...
And keep in mind batteries are usually around 13.4V, so it is 134A, just around 1C rate.

It's not the voltage that determines the C rate. It's the amp hour rating. Their 138amp hours. Or maybe a bit less because of the degradation so by chance 134 is about right.

 

[Perrybuilds]

For the cells balancing only you can use the Valence software, or the open source arduino bms project linked in this thread too.

The Thunderstruck activates balancing just not between modules so if you are running 12v the thunderstruck does everything you need, besides monitoring ... It uses putty and is garbage on that front.

My batteries blink green every 5 seconds with the Thunderstruck vc1 plugged so it wakes them up .

 

[ericgrand]

It's not the voltage that determines the C rate. It's the amp hour rating. Their 138amp hours. Or maybe a bit less because of the degradation so by chance 134 is about right.

I was calculating the amp following the 1800W asked by Corbury. 1800W at 12V gives 150A but if you consider battery is more around 13.4 rather than 12V, it lower the AMP around 134A.
Having 2 in parallel will gives a C/2 charge on the battery which is no problem.

 

[ChasRob]

Hi - I'm a noob here - but I have a question about XP batteries Vs. LifePo 280Ah 4s 12V setup. I'm working on a van build and I need to support a load like 1800W at 12v. That's around 150A with headroom like 200A.

option 1: EVE LifePo 280Ah 4s 12v battery with 250A Daly BMS
option 2: 138Ah Valence XP batteries x 2 (= 276Ah) with thunderstruck BMS

Thoughts on the pros and cons of the Valence option? will it support this type of load?

Thanks, C

I am look at buying 4x 280ah 3.2 V cells from China with a 300A Daly BMS, that is 1,120ahr v/s 260ahr from the valence. I have two U27-12XP that where used and they can not handle a 150amp/DC load. The cells from china are new and cheaper so that is the way to go, wish I knew this when I bought the 2 valence batteries that cost me $850.00.

 

[ericgrand]

2 Valence, connected in parallel, are perfectly able to sustain a 150A load, which is 75A per battery...Unless your batteries are completely toasted, which is still an option.

 

[ChasRob]

2 Valence, connected in parallel, are perfectly able to sustain a 150A load, which is 75A per battery...Unless your batteries are completely toasted, which is still an option.

Yes the valence should handle the load, but they don't, I am ordering a load testing device to see what they can handle, this is the problem with buying use batteries. Now that LIfePo4 are getting so cheap from china there is no reason to buy used batteries.

 

[ericgrand]

Have you checked the balance of internal cells? It may be, if the battery were kept instorage for too long that internal unbalance prevent the battery to deliver full power...
If you have screenshot of the Valence software page it could help.

 

[Travis]

Yes the valence should handle the load, but they don't, I am ordering a load testing device to see what they can handle, this is the problem with buying use batteries. Now that LIfePo4 are getting so cheap from china there is no reason to buy used batteries.

I remember hearing about your batteries that weren't working right. I'm curious what their history is? Did you get them directly from a seller who got them from their original installation? Or did you get them from somebody In between that person and you who may have abused them?