Valence XP Super Thread

[ericgrand]

The BMS won't throw any errors. The state of charge will jump to a hundred percent when you fully charge the battery. most of the internal state of charge meters aren't even accurate anyway.
I've got batteries that claim to be discharging when there's nothing hooked up. Eventually they show a super-low state of charge then as they showed that low state-of-charge I can do a capacity test and it turns out they were still full.

during the capacity test the state of charge goes to zero but the voltage is fine. the BMS does not turn off the contactors until the battery is truly dead based off of cell voltage. The only flag the BMS will communicate is low or imbalanced state of charge. But it simply will not act upon that.

Thanks Travis!
This is an option I will consider at a later stage as finally, over the 14 batteries I have, 1 is dead (one cell at zero with leaking cells...), 6 were recovered from 2,8V to fully charge and give average 139 Ah while being discharge at C/10, and the seven others seems to work as expected!
So I'm short of 1 battery to get both car running. Chasing one in France, but seller is expensive as it is 6 years old but new battery, stored at 13.2V...Price is on the high side at around 500€...
I may bite the bullet anyway as it is a shame to get this car stuck for 1 battery!

 

[marin]

Hi All,
I have a solar setup with 20x Valence U27-XP rev1 batteries, in 5 series of 4 12V batteries, then connected in parallel - to get 48V nominal, and have the ability to disconnect either of the 5 48v strings if there is an issue with battery or cell.
I had the full set from a Smith electric van, and I still have the original HV BMS which isn't connected at the moment. My solar setup is month old so hasn't seen much use yet.
I read this thread start to end, and the other threads on the alternative BMS solutions, eventually realizing my best option is to try and make the factory BMS work. What I did understand is that I need DC-DC converter to get the 100V feed to the BMS, and I will be looking for such converter locally before ordering chinese stuff. What I couldn't get is how to reconfigure the BMS for my setup ?
When I got the full kit a while ago (2-3 years) I didn't have high hopes to make it work properly with the built-in management, and I am thrilled to see how much this community has achieved in short time
I have bought couple of MAX485 boards and I have arduino kits available, so I will try to make 1st step and put together the arduino BMS to at least get monitoring and balancing on cell level working, until I get (with your help I hope) the factory BMS working.
I have 2 contactors that came with the battery pack, I will have to find 3 more that I can control - I saw recommendation for a particular type with PWM control which has lower consumption, are there any additional considerations for it?

Thanks everyone!

 

[floridianman27]

well i finally installed this trunderstruck BMS VC1 in my boat. I got it all hooked up on a piece of starboard got all the relays in a water proof container. Everything working as plan charger working, trolling motor working. Then I installed that board to the boat and finish hooking up my heating pads to keep batteries warm. then all sudden nothing is working. the DC 20 amp relay for my charger is not working right. I have to trip and reset the 60 amp circuit breaker for the trolling motor to come on. too much complex of electrical system. I am going to return this BMS and spend some extra money to buy the drop in batteries and finish this project. 2 months (just several days) is way too long and not getting to what it needs to be done.

 

[nrsmith83]

I just received the Thunderstruck VC1 BMS. I have wired my entire van, but, for some reason, wiring the relay is not making sense to me. I use a Renogy DCC50, which might be a complicating factor. Can anyone post some photos of how they wired the VC1 and its relay?

 

[Surfsolar]

New to the Site but have been lurking for a while.
Im setting up a solar /battery system for my new Promaster van.
I have a 305w Solar panel
2 of the XP U27-12XP batteries
Kisae DMT 1250 DC to DC charger Controller - http://www.kisaepower.com/products/battery-chargers/model-dmt-1250/
* Allows me to charge from alternator as well.
Kisae ABSO 200Watt Inverter/ Charger

I like many of you was quick to buy these batteries at a good deal, and never knew the trouble of cell balancing, over charging and over heating. I figured that the Charge controller could take car of that.
Questions to the pros out there.

If I decide to run only one of the Valence Batteries? Do I need to worry about cell balancing and stimulating the Battery's BMS? My Kisae Charge controller has multiple user settings to set limits on charging and discharge.
Secondly If I decide to run both batteries in Parallel, keeping the system at 12V. What do I really need to worry about with these batteries?
Both have less than 400 charge cycles and are balanced at 13.3 V right now.

All of this Computer hook up and external BMS back and forth is confusing me more than I thought it would.

Bottom line.
If I just hook these up in Parallel with the equipment I have, without balancing the cells every month ( pain in the ass IMO), am I just going to limit some of my output, shorten the battery life, etc. Or would there be something more serious that could happen?
Same questions if I just run a single battery instead?

If I do need a Valence BMS, Can i just hook it up and forget about it and let it do its job or is it something I have to constantly monitor.
I am beginning to think it is more trouble than its worth to use these batteries

Thanks in advance.

Kinda in the same boat, honestly wish I went with battle born, but I’ve got my system set up and running now. 400w solar/Victron MPPT/everything is fused and oversized wire/and BMV-712 monitor. Will probably never discharge these batteries past 50% and have the absorption at 14.2 max voltage so far they have gotten in FL sun is 14.35.

Came back on the forum to find out if I can hook my computer to both batteries at once or if I need to do them separately? But Also very interested in knowing if not using a BMS and not balancing every month if that means less life of the battery or if that is dangerous as in them heating up and catching fire/exploding?

 

[Travis]

I've seen a battery at 18 volts and it didn't heat up. Yes you can hook both to the computer at the same time via rs485 and they'll both balance but you can only see one battery at a time without the BMS and canbus.

If an out-of-balance battery reaches full without having the balance active it will damage a cell very quickly.
A battery can reach full and damage can happen anywhere between 13.6 and 14.6 volts. The more imbalanced the battery the lower the voltage the damage will occur at. Overtime the voltage at which damage occurs could even drop below 13.6. A periodic balance will prevent this from happening and is a must.
. And if it's severely out of balance even with balancing active it will damage a cell unless you have the BMS present to disconnect the bank. Some go out of balance more quickly than others it all depends on the health of the cells.

So I guess my main points are you should balance at least once a month whether you use the batteries much or not. And having a BMS assures no damage happens. As cell health changes surprises will come up even if you think you know your battery well something will always get you without the BMS.

 

[Surfsolar]

Thanks Travis you answered exactly what I needed to know. When balancing the 2 batteries together would I connect the 2 batteries together via communication cables and then one to my computer?

 

[Travis]

Yes

 

[Ed Solar]

I just received the Thunderstruck VC1 BMS. I have wired my entire van, but, for some reason, wiring the relay is not making sense to me. I use a Renogy DCC50, which might be a complicating factor. Can anyone post some photos of how they wired the VC1 and its relay?

Did you check the user manual that came with the VC1 BMS. It has a wiring diagram.

 

[nrsmith83]

Did you check the user manual that came with the VC1 BMS. It has a wiring diagram.

Yes, I have looked at it very closely. I have spoken with Thunderstruck as well. They wanted me to have the relay cut off connected at the controller positive outlet. This would fry my DCC50S when the relay opens the circuit because the panel and alternator would be disconnected from the battery. I am at a loss on how to make this thing work without such damage. I'm curious how others have done it.

 

[nrsmith83]

Hi all, so I've bought the Thunderstruck VC1 and am going to be connecting it to two contactors to control high/low voltage cut off. I'm wondering if anyone has any ideas how to connect them in such a way as to not have them burn out the solar charge controller if the VC1 decides to disconnect them in full sun. I'll be charging using solar, the alternator from my van, and off of shore power.

Thanks!

I'm wondering the same thing!

 

[Travis]

Yes, I have looked at it very closely. I have spoken with Thunderstruck as well. They wanted me to have the relay cut off connected at the controller positive outlet. This would fry my DCC50S when the relay opens the circuit because the panel and alternator would be disconnected from the battery. I am at a loss on how to make this thing work without such damage. I'm curious how others have done it.

Why don't you just put the relay between the solar panels and the charge controller?

 

[ericgrand]

Your controller is lacking a remote switch...Switching off the panel will still let the alternator to take over charging. An option maybe is to simulate an overvoltage through the battery voltage sensor or an overtemp through the temperature sensor.
Then also, this relay should be a safety device. So it should be triggered only to protect batteries. So maybe it is safer to switch off battery and potentially damage the controller just to protect batteries. If settings are properly applied, there is no reason for this relay to disconnet under load.

 

[WinnieVan]

Yes, I have looked at it very closely. I have spoken with Thunderstruck as well. They wanted me to have the relay cut off connected at the controller positive outlet. This would fry my DCC50S when the relay opens the circuit because the panel and alternator would be disconnected from the battery. I am at a loss on how to make this thing work without such damage. I'm curious how others have done it.

Use two contactors -- one on each input -- that way when/if the circuit opens at high voltage it just disconnects the alternator and panels from your DCC50S.

Are you sure the DCC50S would get fried if you removed the battery? I'm pretty sure if you don't have a battery connected -- the charger turns off. Sure -- there might be damage if it happens instantaneously while it is trying to push 50A -- but I doubt it.

Anyways -- a third contactor on eBay is like $50 bucks -- just get one and be done with it.

 

[nrsmith83]

Hi All,

Thanks for your feedback and ideas. I spent over an hour on the phone with Renogy yesterday. As WinnieVan noted, the alternator and solar panel charging capability of the DCC50S complicates things. The good news is that Renogy was able to confirm (hopefully correctly) that if the relay does disconnect the battery, the DCC50S will not be damaged. Thus, I can take the more simplified approach of disconnecting at the positive outlet of the DCC50S instead of the positive side of the panels and alternator.

I just noticed that my relay was damaged in shipment so I need to order a new one then give this all a go!

 

[ericgrand]

If possible, I would use 2 relays:
-one to disconnect charging on cell high voltage, more likely to happen at low charging current because end of charge
-one to disconnect load on cell low voltage, which will keep charging ability to restore asap battery capacity...

I just look at the VC1 manuel and it is how they advise to wire it...

 

[Travis]

If possible, I would use 2 relays:
-one to disconnect charging on cell high voltage, more likely to happen at low charging current because end of charge
-one to disconnect load on cell low voltage, which will keep charging ability to restore asap battery capacity...

I just look at the VC1 manuel and it is how they advise to wire it...

I was racking my brain around this for a while when using the valence BMS. It controls 4 contactors but it's designed for electric vehicles that won't allow the Drive unit to be engaged (discharge)while the charger is plugged in. realizing though that this doesn't matter because the inverter will never take the battery down low enough to cause a cell to go under voltage with a balanced battery. also the charger will never bring the battery high enough for a single cell to go over voltage in a balanced battery.

Simple solution is to only use one of its contactor outputs and connect both relays to it. I know it's not perfectly ideal because then it won't allow the batteries to charge after a low voltage disconnect situation. it will require manual intervention like you'll have to be there to reboot the unit to get it charging again. But since this should never actually happen that is fine with me. It is good that it would force the user's attention because something is actually wrong at that point. If it gets disconnected something is definitely wrong. And the user should figure out which setting caused the disconnect and change the settings to avoid that condition.

With thunderstruck you should be able to use both contactors, charge and discharge simultaneously. but I don't know if it has independent controls of those contactors to disconnect only the discharger in a low voltage condition and only the charger in a high-voltage condition. Has anybody here actually simulated this in real life to see if it works? And if it does I would hope that it would have an audible alarm like the Valence bms does and I would hope it wouldn't stop ringing until it got your attention because at that point something is WRONG!

 

[Solgato]

Well, after a lot of laboring over how to best integrate the Valence batteries into my solar electric catamaran, I decided to go a different route.

Unfortunately the need for an external BMS, balancer, and relays was complicating the system I worked so hard to keep streamlined and simple. But the real deal killer was that my 24V bank is split between each of my hulls without any way to keep the interconnections between the two well protected from the elements.

In the end, I decided to have some batteries custom configured for me from a manufacturer in China. The replacement batteries while not quite as large in capacity, are smaller and lighter, and have an internal BMS will full protection, and the manufacturer was able to build/configure the batteries for me with a higher continuous discharge rating since my dual brushless motors are capable of pulling 100A.

I kept one of my Valence batteries and the Thunderstruck BMS and may install it as a house system in my Trimaran, but I’m not sure if I have room for a group 27 size battery and may switch to something smaller depending on how much solar I am able to integrate into its hard bimini top.

 

[mitchk1303]

Alright I am back after working on my bus build for a couple of months. I want to make sure that I understand my battery bank and charge controller settings. I have 3 u27-12xps in parallel and a victron charge controller. There is a LFP preset that has absorption at 14.2v for 2 hours and float at 13.5V. From this forum I have gathered it might be better to set the absorption down to 13.9 or 14 to ensure un-balanced cells do not get over charged and to increase longevity of the batteries. I've been told that LFP batteries shouldn't have a float voltage so why is it included in the preset? Also this is a dumb question but even though the float voltage is lower (13.5V) it doesn't decrease the charge of the battery correct since it is drawing a very small current?

Basically assuming I balance my batteries (haven't been unbalanced so far) do you think that 13.9 absorption voltage for 2 hours and a 13.5V float voltage are good settings? I also have the option for adaptive absorption so if just a shallow discharge happens the time is decreased and vis-versa. I thought this might be good to decrease the absorption time in order to increase battery life but maybe it doesn't matter since the absorption voltage is set below the max?

 

[Travis]

Alright I am back after working on my bus build for a couple of months. I want to make sure that I understand my battery bank and charge controller settings. I have 3 u27-12xps in parallel and a victron charge controller. There is a LFP preset that has absorption at 14.2v for 2 hours and float at 13.5V. From this forum I have gathered it might be better to set the absorption down to 13.9 or 14 to ensure un-balanced cells do not get over charged and to increase longevity of the batteries. I've been told that LFP batteries shouldn't have a float voltage so why is it included in the preset? Also this is a dumb question but even though the float voltage is lower (13.5V) it doesn't decrease the charge of the battery correct since it is drawing a very small current?

Basically assuming I balance my batteries (haven't been unbalanced so far) do you think that 13.9 absorption voltage for 2 hours and a 13.5V float voltage are good settings? I also have the option for adaptive absorption so if just a shallow discharge happens the time is decreased and vis-versa. I thought this might be good to decrease the absorption time in order to increase battery life but maybe it doesn't matter since the absorption voltage is set below the max?

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.