Correct setting in a solar charger for Valence batteries.

[vedor]

Renogy solar charger lists 4 battery type settings. One is lithium ion battery. I chose that setting
for my 3 valance batteries in parallel but the Renogy tech says I am to chose User setting. Who
is right?

 

[Samsonite801]

Reminds me something like an automotive ASE Certification question.

Renogy solar charger lists 4 battery type settings. Mechanic A says to adjust setting to the 'Lithium-ion battery'
setting for the 3 valance batteries in parallel, but Mechanic B says I am to chose 'User' setting.
Who is right?

A. Mechanic A only.
B. Mechanic B only.
C. Both Mechanic A and B.
D. Neither Mechanic A nor B.


My answer is D. We need to get more info. We should find out the details on the Renogy 'Lithium-ion' profile setting (found in the manual). If we find the voltage settings are desirable to meet our needs (to stay within SoC min and max and promote long-life), then we can leave it there. If we do not like the voltages on that profile, then set it to 'User' profile, and set custom charge profile voltages that we best prefer.

 

[brb58]

You using an external BMS with your Valence batteries?

 

[vedor]

I understand that Valence batteries each have their own BMS. I use a Renogy Rover 40 amp charge controller, 3 Valence U1-12RT batteries in parallel. I have checked both the manual for the charger (advanced parameters for Lithium and User settings) and data sheet for the Valence batteries. I guess that because each Valence battery has it's own BMS the data sheet does not give all the parameters given in the charge controller, thus the uncertainty.

 

[brb58]

I understand that Valence batteries each have their own BMS. I use a Renogy Rover 40 amp charge controller, 3 Valence U1-12RT batteries in parallel. I have checked both the manual for the charger (advanced parameters for Lithium and User settings) and data sheet for the Valence batteries. I guess that because each Valence battery has it's own BMS the data sheet does not give all the parameters given in the charge controller, thus the uncertainty.

They don't have their own BMS. They have a cell balancer and that's it.

Valence uses external BMS

 

[Samsonite801]

Also to note (to augment on what bruceb58 said), Valance use a master/slave BMS architecture and require a master BMS to turn on (to enable) the slave BMS component in the batteries to turn on and function.

Here is an example (read the description):

Battery Management Systems :: Valence Battery Master BMS (VC1)

*Currently Unavailable Price is $250 This VC1 allows use of the original Valence bms that is built into each of the Valence U27-12XP batteries we stock This unit is the Master that controls each of the on-board slave units Only one is needed for each group of batteries wired together The VC1 plugs

www.thunderstruck-ev.com

More info:

How does the Valence U27–12XP lithium ion 12V 128 Ah compare with the Battle Born?

How does the Valence U27–12XP lithium ion 12V 128 Ah compare with the Battle Born?

diysolarforum.com

Valence XP Super Thread

#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...

diysolarforum.com

 

[vedor]

Could you clarify the following statement from the data sheet for the Valence U1-12RT. "No battery management system required" and your recent statement on 01/03/22? Maybe using these batteries in parallel, with a solar charge controller invalidates the data sheet statement? I could not find a external BMS for sale for this particular battery. Does the VC1 work with U1-12RT as well as with the U27-12XP?

 

[Samsonite801]

I referred to the datasheet for the U1-12RT, and indeed it does say "No battery management system required"...

Traditionally, the Valance battery modules have been known to require an external 'master' BMS in order to activate (turn-on) the slave BMSs that are internal to the modules, and this was well known within the DIY community.

I suppose it is possible they could be making a battery module now which no longer operates in this way (requiring an external module to function). In this case where I might be uncertain, I would defer the question to a tech support agent at Valance, and see if they can confirm that this battery module model number can operate in a standalone topology, not requiring any external device to allow them to operate normally.

If they do have this capability, that would be great, to have a module that functions as is (standalone).

That datasheet also contains some good charge specs on it, and you can read the manual for your Renogy charger to determine if the built-in 'Lithium-ion' preset can operate in that window according to the specs on that datasheet. If not, then you can select the 'User' profile on the Renogy to fine tune custom charge parameters.

A helpful doc I like to refer to is this one:

Lithium Iron Phosphave Charge Range

Sheet5 Lithium Iron Phosphate Charge Voltage Range (LiFePO4) What to charge your cells/batteries/packs to. (SOC),Never More than,3.650,Shown is the "FLAT CURVE" of LiFePO4 cells/batteries/packs. What to not discharge past. (DOC),Nominal,3.200,The steap parts on the left and the right are the "Le...

docs.google.com

It has information which can help you to decide the SoC range you want to cycle the battery modules, to promote long-life and get more cycles out of them. Different people here have different opinions about what exactly is considered optimal, but generally speaking, if you keep it roughly in the green range, the lithium packs will last longer than if you take them higher and lower than the green part of the range.

Hopefully this helps.

 

[acamato]

Sorry to resurrect an old thread. The RT series batteries have a built in BMS. The XP series requires an external BMS. The RT series: charge voltage 14.6, float voltage 13.8, max allowed charge before auto disconnect 15.2.