# All Weather Capable?



## twright (Aug 20, 2013)

I have a question about the all weather capability of the average DIY EV:

How well do they handle rain?

I see the use of terminal bars for electrical connections and wonder if those can handle getting wet? I don't see any OEM's using those type of connectors: they all use connectors that are sealed.

Does it matter?


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## evmetro (Apr 9, 2012)

Mother Nature is always trying to return things to their original state, and she will eventually win. We do what we can to slow things down. Mother Nature will begin reclaiming your electrical system via corrosion, which requires an anode, a cathode, and an electrolytic path. On oem EVs, big money is spent on weatherproofing and protecting circuits from Mother Nature, but even those will eventually be reclaimed. We do what we can on DIY EVs, and some do a better job than others do. It takes time and money to do it right, so many people will put the priority on making their conversions drivable, and then fix problems as they occur. Others spend the time and money to do it right. When you build your EV, you should remember that Mother Nature WILL come calling. No stopping her. Do everything that you can to protect your circuits.


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## PZigouras (Jun 5, 2010)

OEM weatherproofing is expensive, but there are other ways to protect your EV’s components. Here are a few inexpensive things that I did to weatherproof my car:

- All junctions are inside sealed PVC junction boxes. I use 3/4-inch sealed PVC conduit to run all the connections. Where I need bare cable (to the motor, for example) I use water-tight cable glands.

- I coat all my battery terminals in dielectric grease, then install color-coded boots over them. I also put a ¼-inch high density polyethylene sheets around each battery pack to keep water and moisture out. They add almost no weight to the car.

- I also installed a HD polyethylene sheet under the car, mostly for aerodynamics, but also to keep splash away from the motor.

- I try to use the stock air box (with a high flow air filter) to cool the motor. This keeps water out of the motor’s air inlet, because most cars stock intakes are usually heavily baffled.

If you get underwater, it is indeed possible for water to get in the motor’s fan/outlet ports, but the fan blades usually push it back out rather quickly. 

As evmetro said, mother nature will always win at the end. But since I've starting doing everything above, I can honestly say that I've never had a corrosion issue (as of yet). I live in an area where flooding is a regular occurance -- and so far, the car has faired very well.


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## sunworksco (Sep 8, 2008)

DC voltage is not such a problem but AC can be.


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## PStechPaul (May 1, 2012)

sunworksco said:


> DC voltage is not such a problem but AC can be.


I'm not sure why that would be so, at least for similar voltage. AC may have higher peaks (1.4 x RMS), but DC may cause galvanic action where material may migrate from the anode (+) to the cathode (-). That also happens on DC contacts switched under load where arcing occurs. It might help to switch the terminals occasionally to reverse the process.

Not being critical, just asking for an explanation or actual experience.


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## sunworksco (Sep 8, 2008)

I was talking about getting shocked from stray voltages.


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## Nabla_Operator (Aug 5, 2011)

I wonder how :

regeneration on RWD works in the wet.

EV's with rear wheel drive can have considerable braking power on the rear wheels and does that make the car instable on wet roads? 

In the sixties all car makers moved from front/rear split braking circuits to the diagnonal combination, just in case you happen to brake with rear wheels only after front failure.

Maybe I install a dashboard switch to be able to disable regeneration. 

Tesla? 

---


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## twright (Aug 20, 2013)

How many people here drive their DIY EV's in the rain?

Has anything special been done to make it rain capable?


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## PZigouras (Jun 5, 2010)

Nabla_Operator said:


> I wonder how :
> 
> regeneration on RWD works in the wet.
> 
> ...


 
If the Tesla detects the front wheels spinning faster than the rear, then the computer automatically slows down the regen until all four wheels reach the same braking speed. 

My guess is that in an emergency situation, the computer would just add more bias to the front brakes. The wet road 60-0 MPH braking times are very impressive for a RWD car this heavy.


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## dougingraham (Jul 26, 2011)

twright said:


> How many people here drive their DIY EV's in the rain?


I just did yesterday.



twright said:


> Has anything special been done to make it rain capable?


Only the obvious stuff like making sure the wipers are in good order and that splash zones don't have anything that can be damaged in them.

Best to keep this in mind when doing your conversion.


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## madderscience (Jun 28, 2008)

I drive in the rain (and occasionally snow too) all the time. 

Most of the AC DIY components (inverters, etc) are pretty well sealed. Some of the DC stuff is well sealed too but some of it isn't. Still, as long as such electrical components are placed thoughtfully in the car they should be pretty well protected even when driving in the rain.

both AC and DC motors won't be bothered by some (fresh and largely clean) water, but fully enclosed AC motors will be most durable. Dirty water will cause increased brush wear even if it doesn't cause any electrical problems, I had this issue with my old MR2 conversion. The motor was running fine but the comm and brushes had worn and I attributed this to the low, rear mounted position of the motor in the car causing more road grit to go through it. It still had many miles to go (I put about 12K on the conversion) but it wasn't new anymore.

The bigger issue is often the battery placement and high voltage wiring. Many lower voltage conversions (156V or less) often have exposed batteries with only minimal protection (such as a plexiglass sheet over the terminals). It is a good idea, and imperative for higher voltage setups, to fully enclose the cells, interconnects and wiring to protect them from weather and keep you or someone else from accidentally dropping a wrench into them or putting a hand in the wrong spot.  This means enclosed battery boxes with lids and nonconductive insulation on all sides, and running high voltage cables through conduits or other protected places.

As far as sealing plugs and such, The problem with sealed stuff is it holds water in as well as keeping it out. I am in favor of intelligent placement out of the way of water spray, etc, followed by use of conductive grease to prevent corrosion.


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