I am currently working on an e-board. my esc is a vesc, which has the following ratings:

  • Voltage: 8V – 60V (Safe for 3S to 12S LiPo).
  • Current: Up to 240A for a couple of seconds or about 50A continuous depending on the temperature and air circulation around the PCB.

I will be using a DPDT switch to switch from charging mode to esc mode. (I'm using a DPDT switch so I can cut the current in half)


Now, I would like to set a fuse as an extra safety to my esc. The problem is when I search online for fuses of 50A, I

  • A)Can't find the fuse itself
  • B)Can't find a fuse holder for 50A

Is there a way to split this in half like I did with the switch ? Or can you direct me to a good site that does have these items?

Also would it be better to put the fuse after or before the switch ?



simulate this circuit – Schematic created using CircuitLab

  • \$\begingroup\$ You have 2 lipo's in parallel ==== (4 because really seriously important) individual pack protection for per cell under voltage and over voltage and per pack over current. It's that or serious risk of outgassing and/or explosion due to extreme imbalance. Apart from that there's no DPDT manufaturer in the world that will guarantee both contacts to connect simultaneously, and the switch-current is always the limiting factor, not the steady-state, so you will have to have a slow-start current ramp up, even in this setup, to avoid burn-in on the "first-connecting" contact. \$\endgroup\$
    – Asmyldof
    Feb 29, 2016 at 16:05
  • \$\begingroup\$ YEa, sorry about that, they are in series. \$\endgroup\$ Feb 29, 2016 at 16:08
  • \$\begingroup\$ About that DPDT, according to link the vesc will only pull that high loads when you are accelerating or going up hill. So since you will be fliping the switch when you are standing still, this should be of any issue ? \$\endgroup\$ Feb 29, 2016 at 16:11
  • \$\begingroup\$ 1: 2 switches in series make no difference to just 1 switch, if anything in parallel is the right configuration, but switch current will not be shared equally. Steady state current (current once switched) will most commonly be shared 40/60 to 60/40 within the same switch. But still a higher-current single pole is much more reliable as a choice. As for whether there is any high current at switch on, only people with actual datasheets know, same goes for what your switch can handle. \$\endgroup\$
    – Asmyldof
    Feb 29, 2016 at 16:50

1 Answer 1


Over here you can find Fuseholders and Fuses in currents around and over 50 A: http://www.digikey.com/product-search/en/circuit-protection

To decide on the fuse location you should consider what is more important to protect and if there is another overcurrent protection in the battery and or charger.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.