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Password Reset , communication failure.

Starting with firmware version 0x17 sometime in 2021, JBD added a password function to the BMS firmware, without telling anybody.

The BMS doesn’t have a physical reset button, so there really isn’t a practical way to implement password protection. (without risking a permanent lockout)

This has caused some of our customers to be locked out of the settings on their BMS if an unknown password is set.

The basic monitoring functions are unaffected, however the JBD android app will not display the basic info without the correct password. The iOS app and the desktop app(s) will still display basic info without the correct password, but will not display parameters.

This is sometimes reported by the app(s) as a communication error because the BMS is not returning the requested data, only the “bad password” message.

The solution may be a password reset

The newest version of JBD’s desktop app includes a tool to clear the password, which actually makes the whole password function useless at best.

There is a screenshot included in the zip file with instructions, since the app does not display english labels on that page.

You can now use our release of Eric Poulson’s BMS-Tools desktop app to send a password reset command.

Either way, You will need a USB communication module.

Find the application download links here: https://overkillsolar.com/support-downloads/

What’s next

After the next version update, the xiaoxiang-bms iOS app will have a password reset tool.

We do not know when a new version of the JBD android app will include the reset function.

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Support and lead time update

Updated as of August 7th 2021: 

  • New orders for in stock items will ship within 2 days.
  • We have been waiting 2+ months for the factory to produce new 4s BMSs.
  • We are now working on redesigning the 4s BMS to use available components.
  • New inventory is now expected by the end of August.

We are answering emails to Support@OverkillSolar.com in the following order:

1. Incorrect orders / Warranty claims

2. Customers who have received their items and are having technical issues (if this is you, include a screenshot of each page of your app, and clear photos of your setup so we can see all of the connections. 9 out of 10 problems are an incorrect setting or an incorrect connection).

3. Status of paid orders / Cancellations

4. Technical questions from pre-purchase customers

5. Lead time questions from pre-purchase customers (These may go unanswered. Our inventory management system is not sophisticated enough to give a better estimate than is stated above)

Please remove OverkillSolar@gmail.com from your contacts, this address is being phased out.

Lastly, we put a lot of time into writing our BMS User Manual, and update it regularly to be more accurate and comprehensive. I am always happy to help, but for the good of everyone, please check the manual first, so I can focus on helping with the hard stuff.

Download the BMS User Manual- Click Here

-Steve
Overkill Solar
support@overkillsolar.com

Return Address:

Overkill Solar LLC
3673 Exchange Ave Suite 3
Naples, FL 34104

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How to charge LiFePo4

LiFePO4 does not need a multistage charging profile.

The manufacturer of our 100 ah cells, and the MFG of the common 280ah cells specifies charging at a rate of 0.5c up to a maximum voltage limit of 3.650 per cell.

Based on the LiFePo4 charge curve the cells will reach nearly 100% charge at 3.500v per cell, so this is our recommended target voltage (14.0v per 4-cell battery, 28v per 8 cell battery).

Note that there is no mention of “float” charging. This is only applicable to lead acid yet most charger designs include a float setting for LiFePo4, usually 13.2v for a 4 cell battery.

Why is this a problem? Because at 13.2v the battery will be significantly discharged, and so you will observe the battery going through a deep cycle after every full charge, even though it remains plugged into shore power.

Therefore the ideal charger for LiFePo4 batteries (in our opinion) is a current limited power supply set to 14.0 to 14.2 volts.