# The little things (like fuses)



## Frankencar (Nov 17, 2008)

Hi there, pros, vets, and experts! I'm getting dang close to ordering the components for my conversion of a 1986 Mazda RX-7. I've been doing my reading, but there's still a few things that elude my grasp. Unfortunately, I'm in a position where I need to order my parts soon (before the month ends) and it turns out it's the little things that are getting me confused. One thing specifically, is fuses. I'm not even sure if it's a good idea to order them online or if I can get what I need cheaper elsewhere. However, I'm swarmed by choices of different Amp ratings, and I don't know what I need. What are the various factors that go into determining what kind of fuses are needed? Any general insight is helpful as well. Also, if there are any other little things that you know from experience that may be easily overlooked, I'd appreciate any other insights. Thanks!


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## madderscience (Jun 28, 2008)

You don't give anticipated specs for your car, but here is a fuse on ebay that would be appropriate for most conversions being done:

http://cgi.ebay.com/FERRAZ-SHAWMUTT-AMPTRAP-SEMICONDUCTOR-FUSE-600-AMP_W0QQitemZ250360041795QQcmdZViewItemQQptZBI_Electrical_Equipment_Tools?hash=item250360041795&_trksid=p3286.c0.m14&_trkparms=72%3A1205%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318%7C301%3A0%7C293%3A1%7C294%3A50

You might find a better price by shopping around more, this was just the first hit I found.

more specs:
http://us.ferrazshawmut.com/catalog/semiconductor-fuses/north-american-round-style/150v-a15qs/

In addition to at least one fuse in series with the battery pack there should be a manual disconnect of some sort that is independent of your main contactor. This is usually either a circuit breaker (preferable) or a big anderson connector rigged so you can yank it apart in an emergency. The circuit breaker is preferable because it will trip automatically (and before the fuse blows if it is sized right) and it can be turned off easily when the car is parked, etc. for an added measure of safety.

Good Luck.


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## PatricioIN (Jun 13, 2008)

I'll give you one piece of advice from a fellow first-timer who's finished his conversion. Spend $75 for one hour's worth of consultation from a professional... 

http://www.evconsultinginc.com/

He will be able to tell you exactly what components you need, and then you can shop around if you like for price. This guy used to own KTA EV in California and has been doing/supplying conversions for years and years. I found him incredibly knowledgeable and very nice to work with. He'll give you a performance analysis of your vehicle with the recommended components along with a price list of all components from KTA. Also, if you use KTA for any of those components, you'll save 5% off list price for having used Ken's consulting services. I saved more on components than I spent on Ken's services, and I felt much better about the stuff I ordered - knowing they were what I needed and that it'd all work together.

http://www.kta-ev.com/index.html

Having said that, make sure you know what you want your EV to do: expected range, speed, acceleration, etc. Ken will also be a good sounding board to tell you if your expectations are realistic.

fyi.. that fuse that was linked below: you can get same/similar from KTA, rated for your coversion for less than on eBay. I looked at a lot of different suppliers and chose KTA for MOST of my components. Some things I sourced locally, like cable and heater components. Some things I bought elsewhere, like charger and dc/dc converter. But I at least had a complete list of components I knew I needed for my 120v conversion.


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## Frankencar (Nov 17, 2008)

That consultation is sounding like a good idea. I checked out KTA...they were super helpful and gave me a quoted package, but they wound up being almost $2000 more than what I estimated from some other sources.

I put my components (or pretty close) on the ol' EV calculator, and got some pretty disheartening results:

Here's a link to my EV Calculations: http://evconvert.com/tools/evcalc/?...60:rim=14:rr=0.015:bs=0.003:kwh=6.99:miles=30:


More details on what I'm planning:

144v system, motor ADC FB 4001
Kelly controller
Zivan NG3 charger
Batteries - undecided...starting to lean toward 24 6v Trojan T-105's, but that's a lot more expensive than going with a 12v pack (or is it?).

Ultimate goal is a commuter...my commute is 16 miles one way with a very slim possibility of charging at work (I can squeeze in an hour...more if I work late, but I would like to plan to not have to charge at work). This includes freeway travel, so speeds of 60mph or so are preferred. I'm hoping for an "on paper" theoretical max range of 45-50 miles or more, just so that I know that traffic or terrain won't leave me dead on the road. Any feedback or insights are very much appreciated!


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## madderscience (Jun 28, 2008)

Frankencar said:


> That consultation is sounding like a good idea. I
> I put my components (or pretty close) on the ol' EV calculator, and got some pretty disheartening results:
> 
> Here's a link to my EV Calculations: http://evconvert.com/tools/evcalc/?...60:rim=14:rr=0.015:bs=0.003:kwh=6.99:miles=30:


The calculations included a headwind and a 2% grade. If you set both of those to zero your range more than doubles at 40mph.

Of course, if your commute really is uphill and into the wind both ways....


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## Frankencar (Nov 17, 2008)

Ha, I guess I put in a little too much resistance there, eh? Then again, it could be uphill both ways... as long as there's also downhill both ways. I'm definitely not driving on purely level ground, however.


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## PatricioIN (Jun 13, 2008)

hmm.. if you want range, you will absolutley want to go with 6v batts and probably the highest capacity (read: weight) you can fit in the car safely. Though you'd probably be fine with 120v system. My car is 120v of 8v's and I can easily reach highway speeds. Also, how many miles you spend at 60mph will affect your overall range as well. The big "if" factor I see is weather. Keep in mind that batteries are rated at 78 degrees... as weather gets colder, batteries don't perform as well. At 40 degrees, they may only give you half the "normal" range. How cold does it get in Oregon? You may also want to look at heated and insulated battery boxes. That will keep your range more constant year round.

When you said KTA was 2k more than other estimates.. is that an actual estimate from other suppliers? I'd love to know who!! Seriously.. I wouldn't mind getting my next conversion parts cheaper now that I'm sure I know what parts I need. Be careful with comparing a complete quote to personal estimates... you might be leaving a lot of "little" things off the list you make yourself that KTA is including in their complete quote. Just a thought... I'm not pushing KTA by any means.. just giving a possible reason why their estimate is more.


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## Frankencar (Nov 17, 2008)

I think that I'm on the freeway about 10 miles each way, then another 6-7 on a road that's 45 with stop and go on each end of that journey. There is a back way, but it's longer, hillier, and curvier than the freeway.Oregon is pretty moderate, not usually freezing, but rarely 78. I was definitely going to look into insulation, maybe a heat pad of some kind would be beneficial as well. As for the estimate difference...that was based on me putting together individual parts, combined with a discount. I know I'm missing a lot of little things, hence this post . I was actually considering KTA's heater core, so if you have any insight into that, that would be great! My greatest concern is my uncertainty with the small parts. If they don't all fit together, none of my big parts will work correctly (or at least safely). I'm thinking you're right about going 6v or 8v though. Any suggestions on a brand/type/place to buy?


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## PatricioIN (Jun 13, 2008)

Frankencar said:


> I think that I'm on the freeway about 10 miles each way, then another 6-7 on a road that's 45 with stop and go on each end of that journey. There is a back way, but it's longer, hillier, and curvier than the freeway.Oregon is pretty moderate, not usually freezing, but rarely 78. I was definitely going to look into insulation, maybe a heat pad of some kind would be beneficial as well. As for the estimate difference...that was based on me putting together individual parts, combined with a discount. I know I'm missing a lot of little things, hence this post . I was actually considering KTA's heater core, so if you have any insight into that, that would be great! My greatest concern is my uncertainty with the small parts. If they don't all fit together, none of my big parts will work correctly (or at least safely). I'm thinking you're right about going 6v or 8v though. Any suggestions on a brand/type/place to buy?


Actually, I didn't take KTA's heater core. I chose a $15 ceramic heater from Target which works just fine until it gets down below 25 or so... then it just knocks the chill off. But I don't believe KTA's unit is any stronger (I could be totally wrong since I haven't seen it). There is more info on my website about my heater setup. I think for the range you're looking at, you will really need 6v batts and heating pads with insulation. I chose Interstate 8v's and have been happy so far. Though, I decided against the heat pads and insulation. My range is definately suffering because of it, but I won't know for sure how much until it warms up to see the difference. I finished my conversion in December.

Obviously your biggest items will be motor, controller, charger, batteries. Batteries you'll find locally. Chargers are all over the place in supply and cost. That leaves you with motor/controller combo. If you can get those two items at a significant discount somewhere, I'd do that. No reason you couldn't do the one hour consult just to get the overall detailed lists of items along with a performance analysis. Then you can look around for the actual components. I have a welding supply house about two miles from me. That's where I got the cable.. paid tax, but no shipping. I got the aluminum for batt racks/adapter plates at speedymetals.com. Charger I got from beepscom.com. It's not as "smart" or fast as a Zivan, but it works fine for my needs (car goes in the garage and gets plugged in every night - all night). It also cost 1/2 the price of the Zivan.

No one can tell you absolutley what you should do. At some point, you have to do what most of us have done, jump in and hope the decisions are correct!


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