# What's the weak link in the EV chain?



## lowcrawler (Jun 27, 2011)

Going to need more info... do you mean "what breaks down and leaves you on the side of the road most?" ... or do you mean something more overarching, like "What needs to be improved before EV's become more mainstream?"


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## electricdominic (Apr 3, 2012)

lowcrawler said:


> Going to need more info... do you mean "what breaks down and leaves you on the side of the road most?"


Yes, this is exactly what I mean.



lowcrawler said:


> ... or do you mean something more overarching, like "What needs to be improved before EV's become more mainstream?"


Nope, looking for the item I should spend the most $$$ on to buy a spare so I don't get stranded.


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## lowcrawler (Jun 27, 2011)

I'm a short-timer when it comes to actual EV _use_ but the only thing that has ever left me unable to get where I wanted was either total pack charge (ie: not enough fuel) or a dead 12V battery.


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## electricdominic (Apr 3, 2012)

lowcrawler said:


> I'm a short-timer when it comes to actual EV _use_ but the only thing that has ever left me unable to get where I wanted was either total pack charge (ie: not enough fuel) or a dead 12V battery.


Yeah, beyond the batteries, what would be the next thing that is likely to fail?


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## eman.cardona (Apr 20, 2011)

It depends on the components you have.. For example, if you have an underrated motor, this will be working always to its peak ratings and this shortens its performance and life time. If you have a kelly controller, this would be the controller will be the weakest link. If you do not have a good DC DC converter, the 12V battery then.. and so forth.


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## Ziggythewiz (May 16, 2010)

I've rarely actually had the ideal stuff to fix an issue on the road, but things I've tried to carry include:

Multimeter (or just DVM)
Spare battery cable (to bypass any failure)
Extension cord for charger
Insulated socket to loosen/tighten battery connections
Whatever tools you've recently used to work on anything (specific socket, screwdriver, wrench, etc)
Spare fuses


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## Qer (May 7, 2008)

electricdominic said:


> Other than the obvious "batteries", what is the weak link in the chain for the complete EV system?


The wallet.

Many people tries to save a few bucks by buying cheap, they're the ones that are mostly likely to have problems in the future. Or simply; you get what you pay for. If you bite the bullet and buy high quality stuff they're more likely to work reliable for a long time.


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## dladd (Jun 1, 2011)

as always, the weak link is the nut behind the wheel. Especially with home built conversions, it's assembly errors and incorrect use of parts that are most likely to be problems. At least that's true for my car...

I carry a multimeter and a credit card. 

so far the worst that's happened to me on the road is a dead 12v battery, but I can jump the contactor for my DC/DC with a quarter, so it's not a real problem.


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## electricdominic (Apr 3, 2012)

Qer said:


> The wallet.
> ..... If you bite the bullet and buy high quality stuff they're more likely to work reliable for a long time.


Exactly!!!! So where do I want to spend a little extra to make sure of this?


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## Qer (May 7, 2008)

electricdominic said:


> Exactly!!!! So where do I want to spend a little extra to make sure of this?


Well, I could give you a hot tip when it comes to the controller.... 

Seriously. It's extremely hard to figure that out since everyone only has a very limited experience of the market; their own hobby project. It's almost impossible for DIY'ers to do an extensive and fair survey of the market since most will only see a very small subset of the available products (and it's usually a bad thing when they're forced to see more than one of each product category). Add to that that everyone will have their own opinion of what's acceptable and what's not so what's good for me might not be ok for you etc.

That means that everyone here will probably recommend what they're used to and if they start a second conversion they'll probably stick to what they know since it worked the last time and thus is considered a safe bet. One exception is JR with his evtv-shows where he obviously spend a lot of money trying different components out, but the problem is that he's also biased by his preferences so I've come to the conclusion that he's not always fair as well (even though he does have a rather broad experience of the DIY-market by now).

I guess the best way to do it is to simply read what others has written about the products, read about others conversions and their experiences, check the wiki here (and you could probably do all a favour by extending the wiki with more kinds of products, more details etc to share your findings), search for posts that contain things like "controller blew up" and see if it's common for a certain brand and how warranty etc were honored and so on.

There simply isn't a simple answer on your question but as a rule of thumb cheap stuff with impressive technical data pretty much always lack a certain something when it comes to robustness and reliability...


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## lazzer408 (May 18, 2008)

If it's a chain driven vehicle the weakest link is.... oh nevermind.

The two failures I had on my EV Geo Metro were a failed controller and a loose battery cable that melted the wire terminal and the battery post. Keep those clean and tight.

The other thing I'd wished I'd spent the money on were the brakes. Geo brakes aren't that strong to begin with and the extra weight wasn't good for them.


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