DIY maintenance and safety for EVs

[Theo]

In the video tutorials of the Varg, in the owner's manual and in their technical pdf files they write that high voltage components should be handled only by qualified personnel.
Yet it seems to me that some people change power units or batteris on their own and some buy Talarias and upgrade them on their own, without mentioning safety.
I've been wondering how safe it really is and whether people protect theirselves when doing those things. I'm starting to gather some information about it on the internet but I haven't found anything very specific yet, like a video about safety guidelines for EV maintenance with technichains showing how they do certain things, just something for general concepts like electrical grounding.
Just as an example, if I wanted to disconnect the battery, would it be a wise idea to clean its plug -probably dirty- pouring water on it before disconnecting it and then waiting until it dries? Should I wear things like insulating rubber gloves or electric static shoes?
I hope that someone can contribute to this thread, hopefully someone who has professional experience in EV maintenance and/or manufacturing.

 

[happyinmotion]

The Stark is a different level of quality and safety to a Talaria or similar. For example, the 400V battery in the Stark has an internal contactor that doesn't turn on until the battery receives the right commands over the CAN Bus. That should make sure the external terminals aren't powered up until everything is connected. Whereas the batteries on the cheaper bikes are much dumber - my Sur-Ron has a 60V battery with that Voltage exposed at the terminals.

As for cleaning connectors - just a wipe with a dry cloth. No reason to put water near electrics even if those electrics are powered down.

 

[ProperHooligan]

There are two things to consider, voltage and current. It’s reported to only take around 100 milliamps to stop your heart. Human skin will start to conduct electricity over 48v. So yes there is a real danger working on these systems without taking precautions. At a minimum gloves rated for the voltage you’re working with when the circuit is energized is a good idea.

 

[datadog]

EV batteries are generally safe until there is loss of isolation, or things like welded contactors or cell imbalance. If you are looking for info on the internet, Google isolation loss and HVIL.

 

[Theo]

There are two things to consider, voltage and current. It’s reported to only take around 100 milliamps to stop your heart. Human skin will start to conduct electricity over 48v. So yes there is a real danger working on these systems without taking precautions. At a minimum gloves rated for the voltage you’re working with when the circuit is energized is a good idea.

Research done: apparently there are different classes for those gloves according to the ASTM D120 standard, that is used even here in Italy: the 00 class should be suitable for the Varg, since it's approved for 500 V AC or 750 DC. They seem affordable.
A piece of advice I've liked is to test those gloves for air leaks before use to make sure they are not pierced.
Considering that they look so thick, though, especially when protected against cuts and abrasions by other gloves over them, I suspect that they would make it difficult to use tools etc., so I also like the idea of using one unportected hand only when possible so that it's unlikely that voltage would pass from one hand to the other through the chest; I guess that using some insulator under the feet should prevent the current from passing from that hand to the ground.

If you are looking for info on the internet, Google isolation loss and HVIL.

Done it, thanks; from the videos I've seen, it looks to me like the battery of the Varg has an HVIL connector, with a pair of low voltage pins and a pair of high voltage pins.

 

[datadog]

If busbars are not exposed, Cat zero gloves are not a requirement, but are recommended f you are not certain of battery health. Test them every time you use them and replace them yearly.

 

[Theo]

The Stark is a different level of quality and safety to a Talaria or similar. For example, the 400V battery in the Stark has an internal contactor that doesn't turn on until the battery receives the right commands over the CAN Bus. That should make sure the external terminals aren't powered up until everything is connected.

Does this work when the bike is shut down, meaning with no light at all from the LED in the control switch? In their video and pdf tutorials they say that the bike should be turned off before disassembling electrics or electronics, but in their videos and documents sometimes they consider it "off" if it's in standby mode with a flashing red LED and sometimes when the LED is completely off...

 

[happyinmotion]

It should do. The whole point of an EV contactor is to make sure that high voltages are not exposed under everything else is connected and powered up and working correctly.

 

[Theo]

Some useful information here:

 

[F451]

Some useful information here:

Excellent video, I learned a lot, thank you.

 

[Philip]

Some useful information here:

This is a must-know for any EV owner, and a mandatory info for any EV tinkerer. Thank you. Stickied!

 

[Aleksandar13]

When stark sends you something like a replacement battery, motor etc and you install it yourself, is this voiding the warranty? Seems I'm seeing more and more dealers not even wanting to deal with issues on this bike. It has me a little concerned. Generally a warrantied item will only keep its warranty if it's serviced by a reputable shop.

Don't think this is the case with them,they will possibly connect to the bike after the battery has been replaced by yourself run checks and your good with the warranty

 

[Erwin P]

I've replaced the battery and motor under warranty myself. It does not affect following warranty assured Stark to me.

And it's 400V DC, true, but a household here in Europe is 230V AC, also very capable of killing you and in the same danger setting, yet everybody works with it.

The connectors of the battery are quite sunk in. Wash them and blow them dry with compressed air before removal. Using isolating gloves while removing the battery connector won't work.

Next time i have the plate work off i will measure the Voltage as i'm quite sure there won't be any. If the VCU does not order it, the battery will not power the bike. That's the relais you hear clicking when you start the bike. It's actually in the battery.

 

[Theo]

I've replaced the battery and motor under warranty myself. It does not affect following warranty assured Stark to me.

Thanks for the clarification.

And it's 400V DC, true, but a household here in Europe is 230V AC, also very capable of killing you and in the same danger setting, yet everybody works with it.

Well, everybody plugs and unplugs things -which needs to be done taking precautions-, but not everybody does more dangerous actions like connecting wires to sockets, for example, and those who do need to know what they are doing. Now, the typical EV dyier works with modular components as far as I've understood, so it's more like plugging and unplugging, but some make their own wiring or work with custom made batteries that can make short circuits if not handled correctly, for example.
Besides, here in Europe we have roughly 3.5 kw of power from the wall, whereas the Varg's battery can produce 80 kw, with a voltage not so higher but with a much higher current and, because of their power, I suspect that even less powerful electric motorcycles have the potential to kill: their voltage is way smaller than 400 or 230 V but maybe enough to make the human body a conductor and the current is way higher.

Another thing to consider is that, as vehicles get worn, they may lose insulation and so I'd like to know whether my bike has some system to check that the insulation is proper; it seems like it does since I've read someone reporting such warnings on the Stark phone.
Maybe I'll make some conversions of ICE bikes in the future and it could be proper to even test insulation myself but again to do this I think that I should really know what I'm doing.
BTW I've found a couple of interesting resources about this to start having some knowledge:
an article to understand those 500 Ω/V
a video from a professional about how to use a megohmmeter:

Bottom line: those things are dangerous and therefore I strongly believe that we should have as much awareness as possible about the dangers.

 

[Erwin P]

It's good to mind safety but you're overthinking it a little.

A current needs a circle to flow. The danger of household applications is that they are all connected to ground so you touch a live wire you will always have a circle.
Same goes for 12V battery systems found on ICE bikes where the - is connected to the frame.

However EV's have a + and a - wire, wich is nowhere connected to the frame, were you to touch the + without touching the - nothing would happen.
This makes it quite a safe system to work on, especially since the pins are soo deeply sunk that touching them with your fingers is almost impossible.

Maintenance is about replacing modules on these bikes so a very safe thing to do. Modifications, well, people are modifying everything. ICE engines, brakes, suspension... These things can lead to serious injury as well.

The Stark had an insulation loss detection.