At 09:07 AM 8/13/02, you wrote:
>On Monday, August 12, 2002, at 09:40 PM, Peter VanDerWal wrote:
>>Remember this box will probably be holding over 1/2 ton of batteries, do
>>you really want to risk having them come loose at speed when you hit a
>>bump or have an accident?
>
>Actually, it'll probably have more like 300-390 lbs. But no, I don't want
>to have them come loose in an accident! I believe that a properly bolted
>box can be just as strong as a welded one, maybe even stronger as long as
>you use the correct materials and mounting points.
A welded-in battery box is stronger. Actually, it's MUCH stronger,
especially in an accident where the box will bend. Think of a piece of
paper fastened to a wall with thumbtacks versus the same piece of paper
glued to the wall along it's edge.
>>I doubt the original tank will be cube shaped, they tend to be curved.
>
>Actually, I was thinking that the curves might help. I can sit the
>batteries on the flat floor and fill the curves with insulation. The tank
>is held very securely to the car as it is, so why try to reengineer it?
>
>>Plexi glass tends to be pretty brittle. If you actually have someone sit
>>on it it might break, unless it's fairly thick in which case it will cost
>>more and weigh more than a good piece of plywood or better yet sheet
>>metal (with suitable stiffening).
>
>They won't actually be sitting on the plexiglass. The seat pads will be
>mounted above the battery window.
Use Lexan (poly-cabonate) instead of Plexiglas (acrylic).
>>>Alternatively I could just use the existing spare tire space to mount
>>>all of the batteries in, but that would put the weight further back than
>>>I was hoping for.
>>You're joking right? There is no way you will be able to mount enough
>>batteries in the spare tire area to go more than a mile or so
>
>I think you'd be surprised how big the spare tire well is on this car.
There is no way that you could possibly fit more than 5 miles
worth of batteries in the spare tire well. With lead-acid batteries, figure
on about 500 pounds of batteries (typically more) per gallon of gasoline.
If the car got, say 35 mpg, you would need at LEAST 500 pounds of batteries
to make the car go 35 miles. You could only go 35 miles on the highest
quality lead-acid batteries, perfectly broken in, at the optimal
temperature, and 100% discharged. Once the batteries aged, or were cold,
you would not be able to go 35 miles. Also, if you discharge lead-acid
batteries to 100% on a regular basis, they will have a very short lifespan.
While this wouldn't give perfect battery placement it would let me
avoid cutting any large holes in the car that, even if reinforced with a
welded battery box, would weaken the car in the event of an accident.
A welded-in battery box does not weaken the car, especially if you
make the box out of thicker sheet metal.
>>Get some cardboard boxes (or large foam blocks) and cut them down until
>>they are 10" long, 7" wide and 9" tall. That is roughly the size of an
>>Optima YT with an extra inch on top to give clearance for the terminals.
>>Now you can position these mock-ups to see where and how they will fit.
You can get a couple of "dummy batteries" from Optima.
>Speaking of Optima terminals. This brings up another one of my
>questions. I'm going to bury it in here with this response, so I hope
>that it doesn't get lost to too many people.
>
>I haven't seen any Optimas with the EV recommended lug-style
>connections. They all have standard automotive posts. I take it that
>this isn't really a problem, since the Optima is still one of the most
>preferred batteries for EVs, but how is this issue dealt with?
The automotive posts seem to work better in EVs than the threaded
posts. You can get the "Blue-Top" marine style deep discharge Optima
batteries, but you will pay a bit more for these, even though they are
identical internally to the YellowTops. Be careful not to get the SLI
BlueTops as they will not last long in you EV. The SLI marine Optima is the
same as RedTop inside.
>>Oh yeah, use a 12V fan. The fan that comes in normal heaters is designed
>>for AC not DC, the element does care but the fan will.
>
>Won't the fan that's already in the heating system work?
>
>>Yes but are you going to have a stout enough 12V system?
Not really a problem. The heater fan typically draws 10 amps or so.
A lot of folks run the AC pump from the tailshaft of the traction
motor. While not ideal, it seems to work OK.
>Now we're getting into another one of my questions. I want to have a
>DC/DC converter beefy enough to keep either my stereo or my AC going at
>full blast, or keep both going at moderate levels. :-) I haven't seen
>any DC/DCs that are larger than 40 amps, can I install two of them to get 80?
Yes. It would be wise to use an accessory battery if you intend to
do this.
> Also, why do the EV kit people sell converters for $500+ when I go to
> EVparts.com and they're like $180?
Better sources. :^)
> I'll have capacitors on the 12V system to keep the stereo going strong,
> but should I use an Optima (YT?) for the 12V battery too or would a
> standard starter type be better (red top)?
Get a deep cycle of some sort. You will run it up and down.
_ /| Bill "Wisenheimer" Dube'
\'o.O' <[EMAIL PROTECTED]>
=(___)=
U
Check out the bike -> http://www.KillaCycle.com
