Changing the voltage on the 13S charger from 54.2V to 54.6V

[surytj]

Hello to all Endless Sphere users. I have been reading various threads on the forums for a long time and thank you for your knowledge. Thanks to you I was able to install the mid engine in my bike.

1) However, I have a problem with the Wato charger.
Currently, the charger gives a maximum of 54.2 volts. I would like to increase the charging voltage to 54.6V. BMS starts to balance me from 54.4V. There are two potentiometers inside VR1 and VR3 (on attachments). Does anyone know which one is responsible for changing the voltage? I wouldn't want to over-regulate something.

2) The second question concerns the idea of lowering the voltage to 4.1V per cell.
To achieve this I thought about making a box with two rectifier diodes connected in series (voltage drop by 2 x 0.7V= 1.4V). 5A diodes with soldered heat sinks.
Usually I would charge the packet to 4.1V/cells.
Every few charges I would charge 4.2V/cells to balance the battery.
Will such a solution work properly?

Thanks for your help, Tom.

 

[john61ct]

Get a BMS that lets you lower start-balance to 4.05Vpc

Only go higher than 4.1Vpc for occasional maintenancee, cap benchmarking etc.

Dunno from that charger but I'd just try and see using a good DMM at the battery end.

 

[flippy]

you cn change the voltage with the trim pots on the top right.

but do NOT do this unless you have a smart bms you can set the balance voltage on.

 

[john61ct]

Or rather, ensure that your setpoint is higher than your BMS start-balance voltage.

Or stop doing your balancing using the BMS, get a better designed device

 

[TommyCat]

Hi surytj,

And welcome to the forum!

Here is a great thread I like to share with a different charger, but it gives you a good idea of how to set up your charger and how it operates. You may get an idea of which potentiometer does what, from their corresponding positions.

https://electricbike.com/forum/foru...-to-adjust-the-luna-charger-mini-and-advanced

Make sure you use an accurate and reliable multi-meter And check the voltage of the charger with the battery disconnected if possible to eliminate a possible battery issue.

I've heard of the diodes in series dropping the voltage which is fine. But the poster also mentioned that it would still trickle charge until manually shut off. Perhaps his was just set for a too low of current shut-off. Just wanted you to be aware. :wink:



Regards,
T.C.

 

[john61ct]

I would agree it is important to get a known-good fresh battery to work with.

But would think best to calibrate with the (also known good, accurate) voltmeter

measuring that the CV voltage is what you actually want **at the battery**

rather than unloaded OCV from the disconnected charger leads.