Valence XP Super Thread

@Solgato - Thanks for the great info. Very helpful. I'm curious about the inside of the BMS: quality, conformal coating, potting, PCB components, etc. Have you taken it apart yet to have a look?

General question....
Both Valenve U-BMS and Thunderstruck are powered by 12 VDC. I'm having trouble understanding where this should be connected. The wiring diagrams aren't really very clear, they just show a 12v source. I guess the choices are either from the battery itself, or before the charge contactor, or after the load contactor. It would need to be a source independant of the state of contactors, so either one being open wouldn't turn the BMS itself off and affect the ability to control the other. So that means it should connect to the LFE battery. Is that correct?

luxnut said:

General question....
Both Valenve U-BMS and Thunderstruck are powered by 12 VDC. I'm having trouble understanding where this should be connected. The wiring diagrams aren't really very clear, they just show a 12v source. I guess the choices are either from the battery itself, or before the charge contactor, or after the load contactor. It would need to be a source independant of the state of contactors, so either one being open wouldn't turn the BMS itself off and affect the ability to control the other. So that means it should connect to the LFE battery. Is that correct?

Click to expand...

Yes it connects to the battery it's protecting if you're running a 12-volt system. Personally I'm connecting mine after the relay so that when the relay is disconnected the BMS itself will have no power so that way it won't continue draining the battery in a low voltage cutoff situation. I'm going to have a momentary push start button to enable it.

Has it been confirmed that the internal cell balancing ("intra module" balancing) can only be activated by a U-BMS or the PC software? Because the manual makes it sound automatic, "passive," even. The PCB assembly (PCBA) is powered by the battery ("module") and operates its internal protections and the LED indicator. The PCBA does extensive communicating with the PC software or U-BMS, including balance status. But it seems to do most of its work autonomously. See all the non-reporting functions listed in the manual:

From "Valence XP Power System User Manual" Section 5.5 Functionality:

• Cell block voltage measurement
• Current shunt voltage measurement, i.e. each module keeps track of its current flow
• Temperature sensor monitoring; each module has 1 temperature sensor per cell bank and at least 1 SOC calculation for the module
  on PCBA (thermistor type)
• RS485 communications with the U-BMS; the following data is sent to the U-BMS

• LED indicator for basic status of the module (see Section 7.)
• Cell block to cell block balancing, also known as intra module balancing. This compensates for slight capacity imbalances between the different cell blocks within the module. Each cell block has a shunt resistor which can be switched in or out of circuit. begins when the cell block voltage is >minimum threshold value and > 40mV higher than the lowest cell block voltage in the module. (see later section 8. for details of balancing technique)
• Non Volatile Memory with event logging capability and stored lifetime Watt Hour counter. (Rev 2 Only)

From Section 8 (Charging Profile & Methods):


Is it possible the software is just letting you see the intra module balancing as it happens automatically, rather than "activating" it? Of course, the RS485 communication item, "Cell block balance on/off" also could mean the U-BMS or PC software can turn it on or off. But if that's the case, why would you want to turn balancing off? Seems like something you want active all the time.

I just received delivery of two U27-XP12's, and I also just ordered the parts to build the cable for the PC software. If it's already confirmed that the U-BMS or PC software is required to turn on intra module balancing, does it stay on, since the PCBA has non-volatile memory?

And whether it is on by default or has to be activated, does this mean a $70 Victron Battery Balancer would be adequate for inter-module balancing for smaller battery banks like mine? Victron says one is required for two 12V batteries, or 3 units for 4 batteries, and at that point it's still cheaper than a full blown U-BMS or the Muller Valence BMS.

I just found out about the Thunderstruck VC-1, which is an intriguing proposition at its price point, especially for a smaller battery bank (2-4 batteries). If the Valence internal battery balancer is indeed confirmed to require constant external input to operate, then the VC-1 would seem the most cost-effective solution for the time being, especially once they activate inter-module balancing and thermal shutoff. It would then replace an external Victron battery balancer, I presume?

childcarepro said:

I just received delivery of two U27-XP12's, and I also just ordered the parts to build the cable for the PC software. If it's already confirmed that the U-BMS or PC software is required to turn on intra module balancing, does it stay on, since the PCBA has non-volatile memory?

And whether it is on by default or has to be activated, does this mean a $70 Victron Battery Balancer would be adequate for inter-module balancing for smaller battery banks like mine? Victron says one is required for two 12V batteries, or 3 units for 4 batteries, and at that point it's still cheaper than a full blown U-BMS or the Muller Valence BMS.

I just found out about the Thunderstruck VC-1, which is an intriguing proposition at its price point, especially for a smaller battery bank (2-4 batteries). If the Valence internal battery balancer is indeed confirmed to require constant external input to operate, then the VC-1 would seem the most cost-effective solution for the time being, especially once they activate inter-module balancing and thermal shutoff. It would then replace an external Victron battery balancer, I presume?

Click to expand...

I don't have a ton of time tonight to answer all of your questions, ill try and circle back tomorrow.....

I'll be honest, get a genuine HV valence BMS from eBay and we can help you reprogram it. You'll just need a buck booster to run it at the high voltage it requires to turn on. It can work with any voltage battery setup, and I was able to get the canbus connection to the BMS with the valence software working. This allows you to monitor all of the batteries at the same time.

To the others out there who would like to connect to the BMS through CAN, purchase the following canbus adapter. It works out of the box with the valence canbus software.

kmh5147 said:

I'll be honest, get a genuine HV valence BMS from eBay and we can help you reprogram it. You'll just need a buck booster to run it at the high voltage it requires to turn on. It can work with any voltage battery setup, and I was able to get the canbus connection to the BMS with the valence software working. This allows you to monitor all of the batteries at the same time.

Click to expand...

I found two on eBay: a used U-BMS-XP-HV, and a new BMS-LV at $599. The $599 is hard to justify for two $500 batteries; the $280 is justifiable if:

1. I need it to keep my cells balanced);
2. It works with my U27-12XPs.

If the internal BMSes will keep the cells balanced, I prefer to use the Victron battery balancer.

Thanks!

childcarepro said:

I found two on eBay: a used U-BMS-XP-HV, and a new BMS-LV at $599. The $599 is hard to justify for two $500 batteries; the $280 is justifiable if:

1. I need it to keep my cells balanced);
2. It works with my U27-12XPs.

If the internal BMSes will keep the cells balanced, I prefer to use the Victron battery balancer.

Thanks!

Click to expand...

childcarepro said:

I just received delivery of two U27-XP12's, and I also just ordered the parts to build the cable for the PC software. If it's already confirmed that the U-BMS or PC software is required to turn on intra module balancing, does it stay on, since the PCBA has non-volatile memory?

And whether it is on by default or has to be activated, does this mean a $70 Victron Battery Balancer would be adequate for inter-module balancing for smaller battery banks like mine? Victron says one is required for two 12V batteries, or 3 units for 4 batteries, and at that point it's still cheaper than a full blown U-BMS or the Muller Valence BMS.

I just found out about the Thunderstruck VC-1, which is an intriguing proposition at its price point, especially for a smaller battery bank (2-4 batteries). If the Valence internal battery balancer is indeed confirmed to require constant external input to operate, then the VC-1 would seem the most cost-effective solution for the time being, especially once they activate inter-module balancing and thermal shutoff. It would then replace an external Victron battery balancer, I presume?

Click to expand...

yes you're correct if thunderstruck adds the module balancing and thermal protection it would replace the basic functions of the valence BMS. There are a lot of other options the valence BMS has that thunderstruck will probably never have.

Yes we verified that the battery will not balance its own cellblocks unless it's in communication with a BMS or a laptop or a thunderstruck. Frankly it can be in communication with anything. Even a rs232 device which is plainly not compatible. All it needs is some kind of data packet and 5 volts and it will work to balance cells only not modules. Most of the monitoring that you are reading about in the manual does not take place unless the board is awake with communication and 5 volts being supplied to it. if the green light blinks every 5 seconds it's in communication with something. If it blinks every 20 seconds the board is asleep and for the most part off.

As far as intra module balancing that does not work unless you have a valence BMS hooked up to it. being in communication with the laptop will not enable that. if your batteries are only in parallel you don't need it anyway. if your two batteries are in series for a 24 volt set up then you need some type of intra module balancing. I don't know which victron balancers you're talking about but it sounds like they would work. Really though the cheap $25 balancer on Amazon would work as well. the first time you charge the batteries you need to have cell balancing working to make sure they charge up balanced and proper. After that you can do it once a month. If your cycling daily without any balancer on an all parallel setup you should only charge to 13.8 volts. once a month when you have the laptop hooked up and you're doing a balance charge you can slowly push the voltage up to 14.6v and making sure no cell goes over 3.8 volts.

so to sum it up the cheapest option is to balance the cells with a laptop once a month and if there in series balance the modules with the $25 Amazon balancer. But that will not protect you from cold temperatures, over-voltage, or under voltage situations nor will it have a pre-charge resistor circuit for the inverter. Most setups won't require the pre-charge circuit especially if they're small setups.

The valence HV u-BMS needs both 100 volts DC and 12 volts DC in order to function. It's rumored you can substitute the 100 volts for 48 volts with possible instability. So you may need more than one voltage converter if you're not on a 12-volt or 48v+ system.

Travis said:

yes you're correct if thunderstruck adds the module balancing and thermal protection it would replace the basic functions of the valence BMS. There are a lot of other options the valence BMS has that thunderstruck will probably never have.

Yes we verified that the battery will not balance its own cellblocks unless it's in communication with a BMS or a laptop or a thunderstruck. Frankly it can be in communication with anything. Even a rs232 device which is plainly not compatible. All it needs is some kind of data packet and 5 volts and it will work to balance cells only not modules. Most of the monitoring that you are reading about in the manual does not take place unless the board is awake with communication and 5 volts being supplied to it. if the green light blinks every 5 seconds it's in communication with something. If it blinks every 20 seconds the board is asleep and for the most part off.

As far as intra module balancing that does not work unless you have a valence BMS hooked up to it. being in communication with the laptop will not enable that. if your batteries are only in parallel you don't need it anyway. if your two batteries are in series for a 24 volt set up then you need some type of intra module balancing. I don't know which victron balancers you're talking about but it sounds like they would work. Really though the cheap $25 balancer on Amazon would work as well. the first time you charge the batteries you need to have cell balancing working to make sure they charge up balanced and proper. After that you can do it once a month. If your cycling daily without any balancer on an all parallel setup you should only charge to 13.8 volts. once a month when you have the laptop hooked up and you're doing a balance charge you can slowly push the voltage up to 14.6v and making sure no cell goes over 3.8 volts.

so to sum it up the cheapest option is to balance the cells with a laptop once a month and if there in series balance the modules with the $25 Amazon balancer. But that will not protect you from cold temperatures, over-voltage, or under voltage situations nor will it have a pre-charge resistor circuit for the inverter. Most setups won't require the pre-charge circuit especially if they're small setups.

The valence HV u-BMS needs both 100 volts DC and 12 volts DC in order to function. It's rumored you can substitute the 100 volts for 48 volts with possible instability. So you may need more than one voltage converter if you're not on a 12-volt or 48v+ system.

Click to expand...

Thanks for the detailed response, Travis! That was immensely helpful. I do love a bargain, hence the used Valence U27's vs 2-3X $$ for new, and why I'm loath to spend $600 on the U-BMS (which will eat up a lot of my savings from the U27's). But I also want reliability and set-and-forget convenience as long as the price is reasonable, hence the desire for automatic cell and battery balancing and to minimize complexity due to potential points of failure.

"There are a lot of other options the valence BMS has that thunderstruck will probably never have."

What I really want are cell and battery balancing and thermal (over- and under-temp) shutoff. It has a lot of features I won't need (e.g., vehicle-related, as this is a "house" battery system).

Also, I see no mention in the Valence XP system manual about low temperature shutoff. Is there an easy way to add that? Will Thunderstruck add it in the future?

"Yes we verified that the battery will not balance its own cellblocks unless it's in communication with a BMS or a laptop or a thunderstruck."
"As far as intra module balancing that does not work unless you have a valence BMS hooked up to it."

To clarify, cell balancing requires 5V power and ANY communications, but battery balancing (e.g. two 12V batteries in series) requires a U-BMS or an external battery balancer like the Victron or the Amazon one?

I'm getting a 24V setup for my motorhome, so these batteries will be in series. I will need intermodule balancing. I was going to use the Victron Battery Balancer (https://www.victronenergy.com/batteries/battery-balancer) which is designed for keeping two 12V batteries balanced with each other, and pretty reasonable at $65.

"The valence HV u-BMS needs both 100 volts DC and 12 volts DC in order to function."

Not a problem; this is a motorhome application, so even though the battery bank is 24V, I will have a 24V to 12V converter to run the house 12V system, so I can run the HV U-BMS on the 12V. For the 100V, could I use this DC-DC converter to boost from 24V to 100V? https://www.ebay.com/itm/124260980594

Bottom line: is my best bet to get the Valence HV BMS? And there's only one HV and one LV? There are more HV's available than LV's, and a big price difference. As for reliability, if the DC-DC converter fails, only the BMS functions (monitoring and balancing) will fail and not the whole battery storage system, so it's a matter of checking in on the BMS from time to time, and replacing the voltage converter should it fail.

Thanks again, @Travis and @kmh5147 !

childcarepro said:

Thanks for the detailed response, Travis! That was immensely helpful. I do love a bargain, hence the used Valence U27's vs 2-3X $$ for new, and why I'm loath to spend $600 on the U-BMS (which will eat up a lot of my savings from the U27's). But I also want reliability and set-and-forget convenience as long as the price is reasonable, hence the desire for automatic cell and battery balancing and to minimize complexity due to potential points of failure.

"There are a lot of other options the valence BMS has that thunderstruck will probably never have."

What I really want are cell and battery balancing and thermal (over- and under-temp) shutoff. It has a lot of features I won't need (e.g., vehicle-related, as this is a "house" battery system).

Also, I see no mention in the Valence XP system manual about low temperature shutoff. Is there an easy way to add that? Will Thunderstruck add it in the future?

"Yes we verified that the battery will not balance its own cellblocks unless it's in communication with a BMS or a laptop or a thunderstruck."
"As far as intra module balancing that does not work unless you have a valence BMS hooked up to it."

To clarify, cell balancing requires 5V power and ANY communications, but battery balancing (e.g. two 12V batteries in series) requires a U-BMS or an external battery balancer like the Victron or the Amazon one?

I'm getting a 24V setup for my motorhome, so these batteries will be in series. I will need intermodule balancing. I was going to use the Victron Battery Balancer (https://www.victronenergy.com/batteries/battery-balancer) which is designed for keeping two 12V batteries balanced with each other, and pretty reasonable at $65.

"The valence HV u-BMS needs both 100 volts DC and 12 volts DC in order to function."

Not a problem; this is a motorhome application, so even though the battery bank is 24V, I will have a 24V to 12V converter to run the house 12V system, so I can run the HV U-BMS on the 12V. For the 100V, could I use this DC-DC converter to boost from 24V to 100V? https://www.ebay.com/itm/124260980594

Bottom line: is my best bet to get the Valence HV BMS? And there's only one HV and one LV? There are more HV's available than LV's, and a big price difference. As for reliability, if the DC-DC converter fails, only the BMS functions (monitoring and balancing) will fail and not the whole battery storage system, so it's a matter of checking in on the BMS from time to time, and replacing the voltage converter should it fail.

Thanks again, @Travis and @kmh5147 !

Click to expand...

I've seen that victron balancer on Amazon it did not have good reviews. I've never tried one.

To clarify about the balancing yes you are correct.

No mention of low temperature shut off in the XP manual. I just looked through and did a keyword search and couldn't find anything either. It ever-so-slightly hints towards temperature limits but doesn't clarify that it will shut down the battery Bank in a low-temperature situation. It just says we shouldn't charge the battery below freezing. Is there a way to add temperature protection? Yes quite easily. we just have to hook up a temperature control switch in line with the12-volt supply to the contactor. should probably put the temperature sensor in a bucket of water or something so that itrises and falls and temperature more in line with what's going on inside the battery. Should be easy enough to find one on eBay.

The voltage converter you linked to only goes up to 32 or 36 volts or something that wasn't high enough. It needs 100 volts.

Assuming you also purchase a contactor. If the DC converter fails the BMS will shut down and stop supplying 12 volts to the contactor (relay) it will open and disconnect battery Bank.

Travis said:

I've seen that victron balancer on Amazon it did not have good reviews. I've never tried one.

To clarify about the balancing yes you are correct.

No mention of low temperature shut off in the XP manual. I just looked through and did a keyword search and couldn't find anything either. It ever-so-slightly hints towards temperature limits but doesn't clarify that it will shut down the battery Bank in a low-temperature situation. It just says we shouldn't charge the battery below freezing. Is there a way to add temperature protection? Yes quite easily. we just have to hook up a temperature control switch in line with the12-volt supply to the contactor. should probably put the temperature sensor in a bucket of water or something so that itrises and falls and temperature more in line with what's going on inside the battery. Should be easy enough to find one on eBay.

The voltage converter you linked to only goes up to 32 or 36 volts or something that wasn't high enough. It needs 100 volts.

Assuming you also purchase a contactor. If the DC converter fails the BMS will shut down and stop supplying 12 volts to the contactor (relay) it will open and disconnect battery Bank.

Click to expand...

Re: Victron Battery Balancer, interesting reviews on Amazon; it's now 4 stars. But it's such a specific use case: TWO 12V batteries in series only, kicks in after 27V series voltage and >0.1V differential. There are so many ways to configure this incorrectly it's hard to know which reviews are based on correct use!

Sounds like I will have to rig up my own low temp shutoff.

Yeah I totally missed that 36V limit! This looks nice, but only 85% conversion efficiency: https://www.ebay.com/itm/133471665289; this isn't fancy, but should work: https://www.ebay.com/itm/133274560782; no efficiency given.

If I also get a contactor then looks like I'd better have some spare 24V to 100V transformers so I'm not left with no DC power to my motorhome.

So just to confirm, the HV U-BMS on eBay is correct? I know the starter of this thread said Valence ones were paperweights, but I haven't read this whole thread. Sounds like we've found a way to make them work?

childcarepro said:

Re: Victron Battery Balancer, interesting reviews on Amazon; it's now 4 stars. But it's such a specific use case: TWO 12V batteries in series only, kicks in after 27V series voltage and >0.1V differential. There are so many ways to configure this incorrectly it's hard to know which reviews are based on correct use!

Sounds like I will have to rig up my own low temp shutoff.

Yeah I totally missed that 36V limit! This looks nice, but only 85% conversion efficiency: https://www.ebay.com/itm/133471665289; this isn't fancy, but should work: https://www.ebay.com/itm/133274560782; no efficiency given.

If I also get a contactor then looks like I'd better have some spare 24V to 100V transformers so I'm not left with no DC power to my motorhome.

So just to confirm, the HV U-BMS on eBay is correct? I know the starter of this thread said Valence ones were paperweights, but I haven't read this whole thread. Sounds like we've found a way to make them work?

Click to expand...

Yes we found a way to make them work. PM us for assistance.
Your eBay links didn't work for me.
I had intended to keep the first few posts updated with current New found information but the moderators have not allowed me to edit those posts. I'll be leaving this website soon in favor of something more user-friendly.

Travis said:

Yes we found a way to make them work. PM us for assistance.
Your eBay links didn't work for me.
I had intended to keep the first few posts updated with current New found information but the moderators have not allowed me to edit those posts. I'll be leaving this website soon in favor of something more user-friendly.

Click to expand...

Wow. Some O.G. stuff here! Awesome. Too bad about the edit restrictions.

I tried to simplify the links, I guess it broke them:

And the HV BMS: https://www.ebay.com/itm/U-Charge-X...ry-Management-system-U-BMS-XP-HV/333542769744

Oh, just reviewed the beginning again... I forgot you started this thread! You've done an incredible amount of research! Thanks for sharing your knowledge.

How about that $599 new LV U-BMS? https://www.ebay.com/itm/valence-LZT-BMS/383645078416?hash=item5953075390:g:3IcAAOSwVPBea4EL Should I just bite the bullet? I'm already spending more than half of that on a used HV U-BMS if you include the buck transformers (need spares) and having to worry about another component that could fail. If I add more batteries it would definitely make the BMS a better ratio of BMS to battery cost. Even now, the $600 is less than 10% of my system cost of about $6K in parts (solar panels, charging, inverter, batteries, cables, connectors, fuses, switches, etc.) PLUS labor. So maybe I'm being cheap? Or do I get the Thunderstruck and wait for them to release intermodule balancing?

Also, my U27's didn't come with terminal hardware (just threaded copper holes). Now you're gonna find out exactly how much of a noob I am. So I found the table in the XP system manual regarding the terminal hardware:
- M8* 1.25-12 - SS? type of SS? flanged? https://www.amazon.com/dp/B088PRG68H/ This one OK?
- terminal washer - what even is this? I'm guessing this contacts the brass terminal and the spring washer and bolt head snug the lugs onto the brass washer?
- spring washer - brass? copper? https://www.amazon.com/dp/B07FBW3HLF/ does it matter?

I'm leaning toward the LV U-BMS at this point.

As a buyer of the eBay lv ubms, don’t do it. After waiting months for it to arrive from China, the seller wasn’t sure about which of a variety of schematic it used to connect. After another month of trouble shooting why it didn’t work, the seller reluctantly allowed a return. I got stuck with $100 return shipping to China, and the seller thought that I should pay another $100 for him to pay the import tariff (didn’t happen). Ultimately it was almost 6 months of a $600 investment that didn’t work, worrying I was damaging my $3k batteries the whole time, when Travis had the HV bms and voltage converter the whole time. HV has been up and running a couple months and every time I check on it everything is totally balanced and maintenance free.

mannytheseacow said:

As a buyer of the eBay lv ubms, don’t do it. After waiting months for it to arrive from China, the seller wasn’t sure about which of a variety of schematic it used to connect. After another month of trouble shooting why it didn’t work, the seller reluctantly allowed a return. I got stuck with $100 return shipping to China, and the seller thought that I should pay another $100 for him to pay the import tariff (didn’t happen). Ultimately it was almost 6 months of a $600 investment that didn’t work, worrying I was damaging my $3k batteries the whole time, when Travis had the HV bms and voltage converter the whole time. HV has been up and running a couple months and every time I check on it everything is totally balanced and maintenance free.

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Oh shoot! Thanks for the heads up. I forgot that was from China. Where do they get off charging that much for a probable counterfeit?!?

And where does one find these junk yard Valence battery trucks?!?

Anyone interested in buying my 2 U27-12XP's? I've decided to go a different direction. Just asking what I paid for 'em, $500 each, I may throw in the unopened diagnostics cable parts. I have not checked them with the software yet, but they're both blinking green, one's at 13.1V, the other at 13.6V.

PM me if you're interested. I'm going to put them on OfferUp but I'll give forum members first dibs. Preferably local pickup in San Diego, but I'll even meet you halfway if you're in California, since we love to RV travel!

luxnut said:

@Solgato - Thanks for the great info. Very helpful. I'm curious about the inside of the BMS: quality, conformal coating, potting, PCB components, etc. Have you taken it apart yet to have a look?

Click to expand...

As I mentioned before, the BMS is not designed for a wet environment and will need to be installed in a different or additional project enclosure bettered suited for moisture.

Here is a photo of the internal board. Pretty straight forward stuff. No potting. No formal coating. Large enough to be serviceable.

When I initially spoke to Thunderstuck, they said that future features (Temp and Inter-Balancing) would be able to be user installed as they would be software/programming based.

It’s going to be some time before I can get my boat back together with these new components (batteries, BMS, Balancer and new solar hardtop), but I will report back when I do.

FYI, last time I talked to Thunderstruck, they had 3 BMS units in stock and I purchased one of them.

Does anyone know where I could buy 2 or 3 of these batteries? (U27-12XP)

Thank you,
Trevor