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#1: I'll try and keep this organized. We're limited to 10,000 characters so this will be a multi part post. If you have an XP battery or a bunch of them this will be a good thread for information on how to treat them properly. We'll discuss what the Valence Brand U-BMS actually does and how to...

#13 Balancer On The Cheap. Maybe you don't need a BMS at all? Like if your inverter shuts down before the battery gets too low and your charge controller is reliable and you have a cheap aftermarket battery to battery balancer. & Every once in awhile in order to activate the internal...

#15 CONNECTOR KIT I bought this connector kit so I could make connecting to the valance plug easier but I can't find it so I ended up Jerry rigging the thing. https://amzn.to/2Hr3zM8 #16 User guide. XP battery manufacturers user guide...

#6 BATTERY BANK WIRING: This is the most common mistake with do-it-yourself and even some professional solar installers. This applies to all parallel connections whether it be just parallel or series parallel. It's easiest to keep the wire lengths the same but it's really about the amount...

The black circles on the side of the u27-12xp reveal screws. You can remove the side cover and you'll have access to the individual wires going to the cell blocks so you could actually hook up a traditional cell balancer like a Batrium or many other far cheaper than Batrium choices. But if you...

!!! VALENCE. u-BMS SUCCESS !!! Last week I finally got the OEM u-BMS fully functional and tested, I proved to myself it's working and doing its job. Now that I finally figured it out I realize it's so much easier than other DIY's like building your own with tons of wires. It's literally...

I did some testing with the high-voltage valence branded u-BMS. I'm happy to report it's working. I have it controlling for contactors although I'm really only utilizing two of them. I flashed the BMS for 2 batteries in series. The hv u-BMS needs 100 volts dc minimum because it's the...

No I've never tried the thunderstruck and don't have any experience with it other than seeing people happy with it on 12 V systems. Don't forget I convert HV units to LV and Flash them properly for your battery bank configuration.

Apparently my "reserved for future use" is useless because I cannot edit them. I guess there's a time limit on editing abilities. That really sucks because I'm not going to be able to update and correct the original posts as our learning progresses. people will be forced to read through...

remember your goal with the contactor is to be able to disconnect the battery. Removing either wire will accomplish this. So to answer your question. Yes you are correct in your 1st idea of where to put the contactor between the battery negative and the body ground.

I gave them a call today and found out some details. This BMS is good for some minor things but the problem for anyone looking to put modules in series is that this bms will not command the modules 12V resistors to activate in order to keep series modules in balance with each other. It will open...

The Ev200aaana is rated for 500 amps. make sure you get the one that has the economizer board on the side. It's basically a pwm board that reduces the power necessary to keep the contactor closed after it initially closes. https://www.ebay.com/sch/i.html?_nkw=ev200aaana&_sacat=0&_sop=15...

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...

The batteries cannot be shut off internally. The thunderstruck will need to be wired to and will open and close a relay "contactor" in order to disconnect the battery Bank when it deems necessary...

I finally got around to doing the discharge test. I drained battery down to 10.8v & the cells down to 2.70 volts. The lowest was at 2.7 volts and the highest was at 2.75 volts. I got out 89% of their original rated capacity according to the watt hour counter in the valence software. With...

Just for a teaser I'll tell you about what's coming. My next version of the BMS all in one box will include a raspberry pi inside communicating with and controlling the valence BMS. This will give an unlimited amount of flexibility with whatever you're doing including home automation and dump...

Over discharged batteries progress update #2 I slow charged them about 1/4 amp It took about 6 amp hours to get them to 12+ volts. Next I hooked up my 50 amp charger and they were quite willing to accept 50 amps but I turned the amperage down to 10 amps. I've got 3 different amp counter...

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...

You should really consider using a pre-charger. It's super simple to hook up. It's especially important with the high voltage. I use about 16 KWH per 24hrs. That's half of what my PV can bring in. That's four time less than the battery bank size. But I always get some PV power even on rainy...

If you guys need a different configuration for your BMS I can send you the config file. As long as it's for your own use as I'm not trying to create a competitor for myself.

The pack stays between 200 and 250 when idling. It ran my house for 6 months and it's much much more efficient than a Honda eu2000 generator.

Yes it will make the cells balance just fine, no problem there

You know what would be the ultimate hack for the XP line? Actually reflashing a chip on the board that's inside the battery. Add some lines of code that as well as do its regular functions also Tell it to activate the 12 volt resistor anytime the battery reaches 14.4v and activate the cell...

I can no longer suggest active balancers that don't have a cut in voltage set point for lfp batteries. Valence is lfp. What recently happened to me is when one cell has a slow self-discharge the balancer in the picture caused all the others to dump their power into its bank of 4 which raises...

I doubt it will do anything other than confuse the rt. Maybe one benefit it could cause the XP To Flash every 5 seconds instead of 20 indicating that its on board balancing is activated. Of course this won't balance battery to battery on the XP side. And I would worry that the battery to...

The quirk I hate the most is it's so easy to pause the meter without realizing it. There's a different model non-wireless that has inductive pickup for DC and it has a feature that's very nice. When it gets to the upper voltage cut off it can reset the state of charge to 100%. That's pretty...

So they've had 480kwh and 578kwh discharge from them. Divide that by their 1.7kwh rating gets you 282 & 339 cycles. Their actual cycle counter doesn't get triggered unless you do a full cycle. Partial cycles don't add to it. I think it's more fair to look at the wh counter to get a better...

I just discovered my XP will not balance its internal cells with its internal balancer unless it's tethered to the valence software on my laptop or the external U-BMS.

you're right about it being voltage dependent. But the resistance determines the voltage under load so batteries with different resistance will pass different amounts of power and if the midpoints are tied 1 battery with a different resistance now affects the entire banks current flow instead of...

I think they're slightly different capacity so it will be harder to stay away from a severely undervoltage cell in a series setup if you mix the black and green. Parallel will be fine. If you paid for green ones and you got black ones I'd be getting your money back if I were you...