DIY Overtime 2.0 pack?

[JoeBlowfromIdaho]

Love my new Altitude PP but I'd like to get more range sometimes. The Overtime pack seems expensive for what I assume is 30ish 18650 batteries? I keep thinking about making a DIY pack and I'm wondering if anyone else has looked into it? You can get the cable alone from RM for under $20 which would make it easier.

Next hurdle would be finding a suitable case for the batteries.

 

[S13]

Keep in mind that the overtime pack is not just a 2nd battery connected to your bike. It is a mobile charging device, similar to your wall adapter. So it needs to provide a regulated voltage and current to charge the main battery properly.

Now technically you could just connect 2nd battery in parallel with the main battery, but you have to be careful with the charging state of each battery. You dont want to connect a full battery to a depleted battery, or you will probably trip the overcurrent detection of the BMS.