Adding a batterty
 

Hello! I have a Izip, E3 Peak electric bike. I would like to put a back rack on it with another 48 volt battery. How do I do this and have it work with the battery that's on it? I would like to have a switch on the battery on the rack to shut on or off and be able to switch to either battery.

mm,

you can do this with a DPDT (double pole double throw) switch of the appropriate voltage [48?] and amperage. Here is an ebay link to a 30 amp DPDT switch.

30 Amp DPDT 3 Position on Off on Toggle Switch | eBay

it may be difficult to find a DPDT switch for that rating of current and voltage, but here is a SPST Battery switch that will work when you use one for each battery. You will also be able to use both batteries at once.

Battery Switch - Medium-duty

Found this battery selector switch rated for 36v and whole lot of amp. It may work fine at 48 volts and 30 amps? About $42

Economical Battery Disconnect Selector Switch: BOTH, 1, 2, OFF