Rad battery and controller repair

[DickB]

If you have a bad battery or controller, I'd be interested in taking a look at it. I would like to know more about these components and see if they can be repaired.

I recently got a bad battery from a Facebook member and found that it had a simple problem - a separated electrical conductor. This type of simple failure is often the case. I repaired the battery at no charge and returned it to the member for shipping charge only. Doing this while in learning mode.

Best to send me a private message.

[DCH3416]

I'd be interested in schematic availability for general purpose component repairs as well.

[DickB]

I don't have a schematic for the Rad battery.

Rad uses a Sino Wealth SH367008 BMS chip, and the spec sheet has a "typical application" schematic which is similar to Rad's implementation, but Rad does use additional parts such as the key switch.

https://datasheet.lcsc.com/lcsc/1810010325_Sinowealth-SH367008X-038XY-AAD01_C160914.pdf
(The spec sheet is in Chinese, but Google Translate does a pretty good job.)

The spec sheet shows a common charge/discharge port, which corresponds to the Rad implementation.  This common port is actually the output power port of the Rad battery. I suspect that this is to allow the regenerative Rad models to charge the battery. But the MOSFETs needed to do this are not enabled with the key switch in the off position, so they are not used for charging via the Rad charger. Rad has additional components to connect to the charge port. The circuit board has to be removed from the batteries to examine the bottom board layer, which I am unwilling to do with my only battery, so complete reverse engineering is not easy or possible. But I have traced and identified key components to the charge circuit not on the Sino Wealth schematic. That path is enabled when a live charger is connected. There are additional components to enable the charge MOSFET, but I have not completely reverse engineered them. 

[DickB]

It is interesting to note that Rad has protection diodes which prevent current from flowing from the battery out of the charge port. Luna advises to plug their charger in first, then connect the battery, because they are concerned that plugging in the battery first would cause a inrush of current to the Luna charger. This inrush is not possible with the Rad battery.  Luna even advised a Rad owner about this, which is not a legitimate concern.  I called Luna out on this in an email, and the tech admitted he was referring to Luna products and did not know about Rad.

If I designed the Luna charger, I would include similar protection diodes in the charger if inrush current from a battery were a concern.