Capataz1624 said:
I purchase. A. 36 v battery I want to see if there's a way to add it to my 48v so I. Cann get more ah.
Unfortunately there isn't a way for you to simply add them to each other to get more Ah.
If your controller supports a range of voltages that include both of those, then you can run on your 48v battery until it is empty, then disconnect it, then connect your 36v battery and run on that until it is empty. The 36v battery will only run your bike at about 3/4 of the speed the 48v battery does, though, typically. (depends on the system)
When you're done riding, then you disconnect both of them and recharge them with their respective chargers.
Also, you cannot use the charger from either one on the other, or you will either damage the battery, or the charger, or both, and risk a fire.
If you were to spend enough time learning about batteries to learn all the dangers in it, and how to do it right (and wrong, so you can avoid that), you could disassemble both batteries and build them into one larger-Ah battery. But this is a very advanced thing to do, and has risks including starting a fire you can't put out, if you do something wrong.
Your best bet is to see if the seller you bought the 36v from will take it back and trade you for a 48v like you already have. You need to first make sure that the 48v battery you have is what they call a "13s", because some places call a "14s" battery 48v (though more call it "52v"), and that's not compatible with a 13s version. You must get the *same* version, so you have either two 14s or two 13s 48v batteries, before you can use them at the same time.
If you had two 48v batteries, you could simply parallel their output wires to run them both at the same time.
Another potential option is to get a "Buck/Boost DC-DC" for each battery, and set the output voltage for both to be exactly the same, then parallel both of those outputs together (while the inputs of both DC-DCs go separately to each of their batteries). But the DC-DC's each have to be able to handle the full power (watts) the bike draws at peak and continously, in case one fails or the battery powering it shuts down. This is not as complicated as disassembling both batteries to make one big one, but there is still risk, and it adds cost and complexity to your bike, increasing the chance of something going wrong on a ride leaving you with no power.