Emergency Battery Pack / Battery Upgrade

A friend of mine purchased a "emergency battery pack" or kind of range extender for his Carbon GT. It's a very simple solution which does not require any modifications to the board itself.

This battery pack consists of a 6S 10.000mah (using a 20.000mah would be ok either) lipo battery and a voltage step-up booster ( this one ). The lipo battery goes to the step-up module which is then simply connected to the board's charging plug. The board can then be charged either during a ride or while taking a rest.

This seems to work great, he's using it frequently and had no issues so far. So I am planning to get one, too. But I have some questions about which he can't answer (since he purchased a pre-configured kit from another guy). Maybe someone could help me here.

First I am not sure how to configure that step-up module for the correct output voltage and current. As you can see under the link above there are two potis that are used to adjust the voltage and current. But how could this be done in detail? What voltage / current would I need to set for the output and how could one test if the output is correct before actually using it?

Second, this solution obviously charges the board's battery constantly. What if the board's battery is fully charged? Will the board's BMS module then prevent the cells from overcharging?

Otherwise it seems to be a very practical solution to extend the board's range.

 

Hi, it depends.
Since on the market there are the so called fast chargers, I assume the board's BMS is ready to handle up to 4 amperes, but I am in doubt about the long term battery health for 4A charging current.
To get back to the topic, you have to do the following:
1. connect the source to your converter, but leave the outputs unconnected;
2. take a multimetter, set it to Voltage and hook it up to the outputs of your Boost converter.
3. with a small screwdriver, twist the VoltageRegulator screw untill you get a reading of ~42V.
4. once you have 42V, get a 10 OHM resistor rated for 200W, and connect one of it's terminals to the positive output of the converter.
5. hook the other end of the resistor to one of the multimetter's probes.
6. hook the remaining probe of the multimetter to the negative output of the converter.
7. make sure to set the multimeters on current reading (A), and use the 10A(fused) scale.
8. power on the converter again, and adjust the Current Regulator screw until you get a reading of 2 (standard charger), or 4(fast charger).

 

That's what I needed to know - thx!

 

small remark, at step 3 you are aiming for 42V. Now the sign is given by the way you connect your multimetter.

 

On the original Evolve barrel connector (that goes from the charger into the board) - is there plus inside and minus outside or the other way around?

 

These boost controllers (boost voltage- input needs to be lower than out put, make sure it’s good for 42v.
When the board is flat it will put in 2a current when the board gets to 42v the current will drop to near nothing, there is a min current on the spec sheet.
I have ordered a couple boost modules 60v 15a

 

Could this be done with a 10s2p battery pack?