Honda Accord build - starting now

[McDesign]

Okay - I've been learning tons here, and playing with e-scooter and e-bike hacks for the kids to get my feet wet. Y'all convinced me that my good 'ol truck was a bad candidate for an E-vehicle commuter - too heavy for the range I needed.

I traded my brother a push-mower (not even self-propelled), for his purchased-new '91 Accord. 211K miles; he's kept it in good mechanical and interior shape, but it's been outside his garage for a few years as newer Hondas have taken over. Everything works, drives nicely at 30 mpg; 5-SP manual should be handy.

front corner

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Rear and truck

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I'm thinking something like the EMC motor and Curtis controller combo from Electric Motorsport - the 85HP max for acceleration should be fine; 35 HP continous should let me Interstate cruise at 70.

EMC motor

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http://www.electricmotorsport.com/store ... curtis.php

Batteries will be Iron-phosphate; we're finally getting into some at work and have a long association with BYD.

I'll likely drive the car for a month or so to check and fix whatever needs it, and get an operating cost baseline. Probably get it repainted.

I believe the conversion should be easy - my only real questions deal with power for the AC compressor, a vacuum pump for the brake master, and the right DC/DC for the normal accessories. There are three Accords listed in the national registry of vehicles.

I plan to detail the build here, including all my mis-steps as I learn how to do this. I'm more comfortable with scooters at this point - here's "Fattie", one I'm building now for my son that will let us try lots of batttery and motor combinations -

Fattie

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Forrest

[SamTexas]

I believe the conversion should be easy...

I envy your optimism. I'll be watching this thread closely as I'm considering a 1991 Honda Civic Wagon conversion.

[McDesign]

Hey, that's great - I hope I can help by showing what NOT to do!

Forrest

[dnmun]

that's a nice car as it is. it will last another 200k if you just take care of it.

you can do a plugin hybrid conversion ofa prius which i think is more sensible for the current times. until there are more people with charging spots in their front yards, i don't think it will be feasible to use EV for local transportation in most areas. they have a large enuff built out footprint in LA where charging is available from public charging spots or shared with others on the evchargernews.com list of EV users who share their home chargers out also so that people can travel across the metro area and be able to charge somewhere to continue on or get home.

i think there may one or two spots where there enuff chargers available in europe, but for the US, i think the plug in hybrid conversion is the best effort to make now.

[McDesign]

Well, I don't NEED an electric car - I WANT one!

My target here is pretty constrained. For two years, I have the following commute five days a week.
69 miles in the AM, of which 62 miles is Interstate. I can recharge at work during the 9 hours I'm there.
14 Miles in the PM, of which 11 miles is Interstate. Recharge at home.

Occasionally, drive 42 miles to the airport, park a few days without recharging, then drive home. That part may be a stretch!

At the end of the two years, my daily commmute drops to 26 miles a day total, four days a week.

Forrest

[Hillhater]

...I traded my brother a push-mower (not even self-propelled), for his purchased-new '91 Accord.

That is one good trade !
Or one very decent brother you have there

[neptronix]

You sure you want to use this car?

Smaller car means less batteries and less power needed ya know..
More aerodynamic car means both..
The Accord is ok but you can do better. And these have great resale value so i think you could get something else.

Jussayin.. maybe a CRX, EG Civic, EK Civic, MX3, small Toyota/Nissan etc may be a good target too.

[Malcolm]

That Motenergy motor has a tail shaft, so the cheap way to provide AC, vacuum and 12V would be to drive the original pumps and alternator using a belt pulley on the tail shaft.

If you don't like that approach you could run a Meanwell 12V power supply straight off your traction pack and use it to drive an electric vacuum pump (and charge your 12V battery). The Audi electric pump is very good and often comes up on eBay. Not sure about AC as I don't need it here in the UK, but if you search on DIY Electric Car I'm sure you'll find suggestions.

The Curtis controller is well-proven, but it does squeal at low speed, as the switching frequency drops to 1.5 kHz

Edit: You would actually want a 13.5V or possibly 15V Meanwell supply to charge the auxiliary battery.

[neptronix]

...i've heard that Curtis controller in person. It does indeed sound broken at low speeds :p
I guess they are really price competitive though? ( important since a car costs oh i dunno.. 10 times as much to convert as our bikes )

[SamTexas]

you can do a plugin hybrid conversion ofa prius which i think is more sensible for the current times.

That does sound more sensible. Has anyone on this board done this before?

[McDesign]

Hey - I've got another pushmower - maybe I can find someone with a Prius and an unkempt yard?

Forrest

[TylerDurden]

So, how many large EVs have a >70mi range?

How much capacity will it take at 60mph?

[McDesign]

It seems that for Lead-Acid, I'd need about 90KWh; with lithium maybe 70KWh. $Tens of thousands either way!

Forrest

[neptronix]

Eh?

The EVs that are coming out have 16-32kWh packs..
( these are consisting of 5C-10C cells though )

Am sure you can use less. Some guys out there are running on only 50AH of lead acid O_O

[SamTexas]

It seems that for Lead-Acid, I'd need about 90KWh; with lithium maybe 70KWh. $Tens of thousands either way!

That's way too high. Typical Ecar consumes 250wh/mi. So you'd need 25Kwh for a 100 miles range.

[McDesign]

Here's a link to the E-S thread on pack size calculations we had gone through a few months ago, when I was trying to make the full-size pick-up concept work - viewtopic.php?f=34&t=24205

Forrest

[SamTexas]

Here's a link to the E-S thread on pack size calculations we had gone through a few months ago, when I was trying to make the full-size pick-up concept work - viewtopic.php?f=34&t=24205

I scanned through that thread very quickly and could not find the relevant info. I'd be interested in a summary on how you came up with a pack size of 70Kwh or more.

[Malcolm]

If you plug the numbers for your car into the Ecomodder calculator: http://ecomodder.com/forum/tool-aero-ro ... stance.php it'll give a pretty good idea of energy use. Taking a CdA of 0.65 and a weight of 3000 lbs it gives a power requirement of around 15 kW at 70 mph, so taking into account electrical system losses, say 20 kW.

So you need 20 kWh for 70 miles range at a steady 70 mph on level ground. Then add allowances for gradients, acceleration and battery reserve.

[TylerDurden]

Plus the weight of PbA and peukert.

[Malcolm]

I know McDesign's original truck plans were for lead acid, but according to the first post here this one will be lithium. I added 300 lbs to the stock weight to round it up to 3000. I doubt you could get enough lead in the Honda to get the desired range without needing serious upgrades to brakes, suspension etc

[SamTexas]

Given all the disadvantages of Lead Acid, I'd completely rule it out unless I want to build a very low speed vehicle (a la golf cart) or a one with an extremely short range (10 or less miles). But who would want such a vehicle?

[TylerDurden]

Ah yes... LiFePO4.

20kW / (3.2V * 20Ah) = 312.5 cells @ 580g = 400lbs.

Add 25% for DoD = 500lbs.


Similar builds:
http://www.evalbum.com/3786
http://www.evalbum.com/3842
http://www.evalbum.com/3801
http://www.evalbum.com/3810

[SamTexas]

That's interesting. LiFEPO4 is definitely a better choice than lead-acid, but why not Li-Co? With a much higher energy density, the weight saving alone is worth the effort. Battery management needs to be there anyway for either LiFePO4 or Li-Co. What's the catch?

[JohnC]

.

[McDesign]

Thanks - I'm going through those.

I mentioned to a buddy about this project, and he just offered this morning that he's selling his VW cabrio conversion (Lead Acid, but the rest is pretty nice) - he wants $5500.

Nah - wanna' build my own.

Forrest