SV-BAT-320 BACKUP BATTERY Replacement

[Bonwit]

Given the rather high price Dynon is charging for the SV-BAT-320, I'm curious if anyone has rebuilt the pack rather than replace it. The pack appears to be a simple 3S2P 11.1v arrangement of 18680 cells, and given that there are only 2 wires going into the pack it would indicate the BMS is internal, and thus be reused. I might consider replacing it with a "smart" BMS instead, so I could keep an eye on the voltage and balance condition of the battery groups For anyone who has opened one up, I'm curious if there is any other protection in the case besides the BMS that Dynon has added. A failed BMS and subsequent overcharge condition could certainly make for a really bad day.

 

[Rhino]

They're 18650s, not 18680s. BMS is in the pack with the batteries. And yes, people have rebuilt them.

More info:

SV-BAT-320 safety

I have a question about SV-BAT-320 battery packs please. Considering a Li-ion battery fire is self-sustaining and can't be put out with a fire extinguisher, for in-flight safety I wish to know if every 18650 cell (x 6 I trust) in the SV-BAT-320 pack has its own internal protection circuit, or...

forum.flydynon.com

 

[RVDan]

Given the rather high price Dynon is charging for the SV-BAT-320, I'm curious if anyone has rebuilt the pack rather than replace it. The pack appears to be a simple 3S2P 11.1v arrangement of 18680 cells, and given that there are only 2 wires going into the pack it would indicate the BMS is internal, and thus be reused. I might consider replacing it with a "smart" BMS instead, so I could keep an eye on the voltage and balance condition of the battery groups For anyone who has opened one up, I'm curious if there is any other protection in the case besides the BMS that Dynon has added. A failed BMS and subsequent overcharge condition could certainly make for a really bad day.

Replacement batteries. https://flyboyaccessories.com/products/replacement-battery-pack-for-dynon-sv-bat-320-housing

 

[Bonwit]

Rhino, yes 18650. I fat-fingered that. And yes, I known the BMS is in the pack. I‘m just curious if there‘s some other protection in there that would justify the high price. I suppose not.

Thanks for the link RVDan. $90 is a far better deal than what Dynon offers, but since I have the equipment and supplies, I think I’ll build my own, with the benefit of knowing exactly what’s inside.

BTW, for anyone interested, you can find .stl files online if you wish to 3D print your own shell to hold the pack. Just search on printables.com, or thingyverse.com for “Dynon”.

 

[Rhino]

According to those who have rebuilt them, no, there is nothing else in there to drive up the cost. And you can reuse the BMS.