# [EVDL] Looking for advice on building battery box



## EVDL List (Jul 27, 2007)

Hello Andrew,

You can get electrical insulator board from a motor shop. This stuff comes 
in thin sheets to over 1 inch thick. You can also get bulkhead electrical 
connections like the type that are use on motors. I ran my battery cables 
through large grommets on the side of the box that are then connected 
directly to the main fuse and safety contactors.

In my epoxy fiberglass battery box which is 1/4 inch thick, I use one 
external exhaust fan that is connected to the box using 2 inch diameter pvc 
water fittings and a pvc 2 inch flexible vacuum hose to connected up to a 
Dayton 6 inch 120 vac blower fan. Install this fan only to exhaust, not to 
blow in air.

Provide on inlet on the opposite corner using the same size and type of pipe 
fittings. I drill a hole in the floor pan for a 90 degree 2 inch elbow 
which is fasten to the body sheet metal by using a 2 inch adapter flange as 
a chase nipple. Point the 90 degree elbow to the rear with a short length 
of pipe. I painted all these white pvc fittings with that new paint that is 
design for plastic.

In than stuff this inlet pipe with that 3-M green plastic filter material 
that is use for A/C units which you can get a most hardware stores.

Roland




----- Original Message ----- 
From: "Andrew Wood" <[email protected]>
To: "EVDL" <[email protected]>
Sent: Thursday, March 17, 2011 4:31 AM
Subject: [EVDL] Looking for advice on building battery box


> Im putting together a design for my battery box which will hold 40 
> cylindrical Headway 16ah cells 40mm diameter 160mm long.
>
> Im thinking of laser cutting two acrylicsheets with 40 holes in. The 
> cells will lie horizontal with one sheet at each end to hold them in 
> position. Once the connecting bars are fitted between the cells that 
> should form quite a nice rigid unit.
>
> Im then thinking of dropping that unit into a vacuum formed plastic box to 
> provide an electrically insulated housing. The box will have a lip on the 
> top, around the edge, onto which a flat top can be bolted.
>
> This presents two issues which I would appreciate some advice on.
>
> 1. The top will need to have two bolts through it which will form the 
> main terminals, Im therefore thinking that the top is going to need to be 
> fairly heat resistant and am not sure which is the best material to use? 
> Maybe some kind of rubber?
>
> 2. I also need to accommodate 5 Manzantia Mk3x8 BMS PCBs, preferably 
> within the vac formed box.
>
> Although theres plenty of space to do this, and the dimensions are such 
> that it lines up quite nicely Im concerned again about heat dissipation 
> from the L shaped heatsinks on the boards. Im thinking of bolting all 5 L 
> shaped heat sinks together to a larger sink to hold the boards together 
> and dissipate the heat better but if I then just drop the 5 boards into 
> the vac-formed box will the heat inside be too much? Really im thinking I 
> need some sort of vent on the top? Again it needs to be insulated really 
> for safety, so maybe a plastic fan and grill?
>
> The BMS boards have the facility to drive a fan.
>
> Thanks
> Andrew
>
> Sent from iPhone
>
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## EVDL List (Jul 27, 2007)

All good points thanks everyone.

Just wondering though about water ingress if ventolation is at the bottom - Im intending to put the battery boxes under the vehicle

Sent from iPhone



> Mark Grasser <[email protected]> wrote:
> 
> > A couple more points.
> >
> ...


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## EVDL List (Jul 27, 2007)

How about this. A small exhaust blower, the inlet side attached to a tube
that sucks from the bottom of the box during charging. 

Sincerely,
Mark Grasser


-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf
Of Andrew Wood
Sent: Friday, March 18, 2011 12:50 PM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Looking for advice on building battery box

All good points thanks everyone.

Just wondering though about water ingress if ventilation is at the bottom -
I'm intending to put the battery boxes under the vehicle

Sent from iPhone



> Mark Grasser <[email protected]> wrote:
> 
> > A couple more points.
> >
> ...


----------



## EVDL List (Jul 27, 2007)

Andrew

I wouldn't worry about water coming in the bottom. If your boxes are
up to the task of handling batteries, they won't be bothered by a
little water. Are you concerned about splashing through puddles? It
will drain. Are you using flooded batteries? If so you should plan on
rinsing them off once in a while to clean them up. It's not like you
are charging with them submerged so I wouldn't worry about sucking up
any water.

The best airflow is probably from bottom to top, with the fan drawing
air out the top as Roland suggested. You want the fans to create a
vacuum by drawing air out of the box, not pressurizing the incoming
air.

Mine have vents in the bottom and every once in a while I'll hose them
off and everything drains out the bottom. No problems. They are made
from 1/4 inch, 5 layer plywood that I fiberglassed after construction.
I coated the inside with a rubberized/flexible roof coating. I have
flooded NiCads and after several years of use there is no sign of any
problems. And yes, I have stuck the hose in there to rinse things out.

DAC

On Fri, Mar 18, 2011 at 1:10 PM, Mark Grasser <[email protected]> wro=
te:
> How about this. A small exhaust blower, the inlet side attached to a tube
> that sucks from the bottom of the box during charging.
>
> Sincerely,
> Mark Grasser
>
>
> -----Original Message-----
> From: [email protected] [mailto:[email protected]] On Beh=
alf
> Of Andrew Wood
> Sent: Friday, March 18, 2011 12:50 PM
> To: Electric Vehicle Discussion List
> Subject: Re: [EVDL] Looking for advice on building battery box
>
> All good points thanks everyone.
>
> Just wondering though about water ingress if ventilation is at the bottom=
-
> I'm intending to put the battery boxes under the vehicle
>
> Sent from iPhone
>
>


> Mark Grasser <[email protected]> wrote:
> >
> >> A couple more points.
> >>
> ...


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## EVDL List (Jul 27, 2007)

Hi Peter,

The book that came with my TS cells says that the electrolyte is a
solution of Lithiumhexafluorophosphate (LiPF6) in a mixture of organic
solvents listed as "Ethylene Carbonate (EC) + Di-ethyl Carbonate (DMC)
+ Di-ethyl Carbonate (DEC) + Ethyl Acetate (EA)." Going by the letters
for the second item I'm thinking it might be Di-methyl Carbonate.

Under normal use lithium batteries should not outgas so taking care of
outgasing is for the situation where something goes wrong.

On Fri, Mar 18, 2011 at 12:15 PM, Peter C. Thompson


> <[email protected]> wrote:
> >
> > Hi Folks,
> >
> ...


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## EVDL List (Jul 27, 2007)

That's why I didn't put vents on the bottom of the rear battery box on the 
Mustang - didn't want water/salt intrusion. I doubt that the batteries will 
get that hot, but...

Joseph H. Strubhar

Web: www.gremcoinc.com

E-mail: [email protected]



----- Original Message ----- 
From: "Andrew Wood" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Friday, March 18, 2011 9:50 AM
Subject: Re: [EVDL] Looking for advice on building battery box


> All good points thanks everyone.
>
> Just wondering though about water ingress if ventolation is at the 
> bottom - Im intending to put the battery boxes under the vehicle
>
> Sent from iPhone
>
>


> Mark Grasser <[email protected]> wrote:
> >
> >> A couple more points.
> >>
> ...


----------



## EVDL List (Jul 27, 2007)

What about fuses and circuit breakers inside the battery box?

Ive got a main fuse and separate circuit breaker but Im a bit concerned about what will happen when I wire the 40 cells in series and thus get 144v. Would I be better connecting the cells in series in say 3 blocks each with a circuit breaker between them to reduce shock risk when assembling?

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## EVDL List (Jul 27, 2007)

Hello Andrew,

It is recommended to install the overload protection devices that will 
produce a arc out of a Glass I, Division II atmosphere. To prevent this arc, 
you either install these devices in explosive proof enclosures or outside 
these areas.

Make sure that when you work on the batteries, is to disconnect the charger 
either by a plug and connector or by a battery charger contactor.

Also the battery pack should be disconnected from the main contactor and 
motor controller either by a plug and connector or by two safety contactors 
which I use that is control by the ON POSITION of the Ignition Switch.

This completely isolates the battery pack from the battery charger and motor 
controller unit and the frame and/or body of the EV which may conduct some 
battery current through the motor and through the brush dust to the motor 
shaft.

It is recommended to not ground the most negative of the battery pack to the 
ground of the EV. If you are using a type of battery that may have leakage, 
the current may flow from the surface of the battery to a conductive 
surface. I also seen the batteries arcing to the vehicle frame in the dark 
or by a infrared sensor equipment that we use to detect leakage in 
equipment.

I could actually see the commutator arcing to the shaft with the lights off 
while I am charging. Also had a full battery voltage from the most positive 
to the vehicle frame. Installing the safety contactors completely isolated 
the batteries from any electrical devices while the ignition switch and 
battery charger was off.

If your batteries are place short rows that are next to each other, the 
maximum voltage between any two rolls will be the total voltage of that 
roll. Lets say you have a 144 volt pack and have four rolls of battery, 
that will be 36 volts of battery between any two rolls.

I am using a 180 volt battery pack with 5 rolls of 36 volts per roll. For me 
this is 72 volts maximum between the end loops of these batteries rolls. For 
me this is low voltage, I am use to working on voltages up to 12,470 volts.

When I work on the batteries, I use several sheets of neoprene rubber to 
cover the batteries that are adjacent to the ones I'm working on. Also 
drape rubber sheets over the any metal surfaces of the vehicle.

I have a set of Kline electrical tools that have insulated handles that is 
rated for the voltage you are working on. You could also install heavy duty 
heat shrink over standard tools. This type of heat shrink gets up to 1/8 
inch thick when apply.

To test the insulation of these tools, you should be able to drop it across 
the batteries where the expose metal parts of the tool will not bridge any 
two battery terminals. The only tool that I do not have this heat shrink 
on, is my inch pound torque wrench. After I adjust this wrench, I slip on a 
rubber hose over the handle.

The ground surface should be also insulated where you stand on. Those rubber 
interlocking floor pads work good. Wear good foot wear with a insulated 
sole and clothes where no bare skin touches the vehicle.

In very high voltage systems, are electrical workers must stand on a glass 
surface that has four insulator legs that hold this platform about 4 inches 
off the ground. It is a requirement for electrical workers that work LIVE, 
must work in two man teams.

Roland


----- Original Message ----- 
From: "Andrew Wood" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Sunday, March 20, 2011 10:24 AM
Subject: Re: [EVDL] Looking for advice on building battery box


> What about fuses and circuit breakers inside the battery box?
>
> Ive got a main fuse and separate circuit breaker but Im a bit concerned 
> about what will happen when I wire the 40 cells in series and thus get 
> 144v. Would I be better connecting the cells in series in say 3 blocks 
> each with a circuit breaker between them to reduce shock risk when 
> assembling?
>
> _______________________________________________
> | REPLYING: address your message to [email protected] only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> | OTHER HELP: http://evdl.org/help/
> | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
> 

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## EVDL List (Jul 27, 2007)

> Andrew Wood wrote:
> > What about fuses and circuit breakers inside the battery box?
> 
> Here is my approach, honed by 30+years with EVs.
> ...


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## EVDL List (Jul 27, 2007)

Another thought is vents on the bottom allow you to wash off your batteries with 
water and let it drain out.



________________________________
From: joe <[email protected]>
To: Electric Vehicle Discussion List <[email protected]>
Sent: Fri, March 18, 2011 11:27:48 AM
Subject: Re: [EVDL] Looking for advice on building battery box

That's why I didn't put vents on the bottom of the rear battery box on the 
Mustang - didn't want water/salt intrusion. I doubt that the batteries will 
get that hot, but...

Joseph H. Strubhar

Web: www.gremcoinc.com

E-mail: [email protected]



----- Original Message ----- 
From: "Andrew Wood" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Friday, March 18, 2011 9:50 AM
Subject: Re: [EVDL] Looking for advice on building battery box


> All good points thanks everyone.
>
> Just wondering though about water ingress if ventolation is at the 
> bottom - Im intending to put the battery boxes under the vehicle
>
> Sent from iPhone
>
>


> Mark Grasser <[email protected]> wrote:
> >
> >> A couple more points.
> >>
> ...


----------



## EVDL List (Jul 27, 2007)

And your lithium batteries would be dirty because?

Sincerely,
Mark Grasser


-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf
Of David Dymaxion
Sent: Tuesday, March 22, 2011 4:30 PM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Looking for advice on building battery box

Another thought is vents on the bottom allow you to wash off your batteries
with 
water and let it drain out.



________________________________
From: joe <[email protected]>
To: Electric Vehicle Discussion List <[email protected]>
Sent: Fri, March 18, 2011 11:27:48 AM
Subject: Re: [EVDL] Looking for advice on building battery box

That's why I didn't put vents on the bottom of the rear battery box on the 
Mustang - didn't want water/salt intrusion. I doubt that the batteries will 
get that hot, but...

Joseph H. Strubhar

Web: www.gremcoinc.com

E-mail: [email protected]



----- Original Message ----- 
From: "Andrew Wood" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Friday, March 18, 2011 9:50 AM
Subject: Re: [EVDL] Looking for advice on building battery box


> All good points thanks everyone.
>
> Just wondering though about water ingress if ventolation is at the 
> bottom - Im intending to put the battery boxes under the vehicle
>
> Sent from iPhone
>
>


> Mark Grasser <[email protected]> wrote:
> >
> >> A couple more points.
> >>
> ...


----------



## EVDL List (Jul 27, 2007)

Smoke from a fire, fire fighting foam from putting out the fire... On a less 
dramatic note, dust (especially if you have been actively ventilating the box 
with fresh air), you spit some electrolyte out of some cells (as I have done in 
tests, if the leak is small a cell can continue to work just fine). If you 
ventilate you might get condensation in the boxes, too.

That does bring up a good question. The electrolyte in a lithium battery must be 
conductive for it to work -- I presume spitting some electrolyte would make a 
conductive path? I'll have to check for that next time I overheat one.




________________________________
From: Mark Grasser <[email protected]>
To: Electric Vehicle Discussion List <[email protected]>
Sent: Tue, March 22, 2011 2:52:24 PM
Subject: Re: [EVDL] Looking for advice on building battery box

And your lithium batteries would be dirty because?

Sincerely,
Mark Grasser


-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf
Of David Dymaxion
Sent: Tuesday, March 22, 2011 4:30 PM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Looking for advice on building battery box

Another thought is vents on the bottom allow you to wash off your batteries
with 
water and let it drain out.



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## EVDL List (Jul 27, 2007)

Can anyone point me in the direction of this 'paint on' insulating 
material please.

Or at least give me a name of what its called. Ive never seen anything 
like that before.

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## EVDL List (Jul 27, 2007)

http://www.edesignaudio.com/index.php?cPath=1_24

Not sure if that's what 
-- 
Sent from my DroidX with K-9 Mail. Please excuse my brevity.



> Andrew Wood <[email protected]> wrote:
> 
> Can anyone point me in the direction of this 'paint on' insulating material please. Or at least give me a name of what its called. Ive never seen anything like that before._____________________________________________
> | REPLYING: address your message to [email protected] only. | Multiple-address or CCed messages may be rejected. | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub | OTHER HELP: http://evdl.org/help/ | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
> ...


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## EVDL List (Jul 27, 2007)

http://www.edesignaudio.com/index.php?cPath=1_24

Not sure if that's what you are after or not but it worked great on my ice mustang as sound deadner.

Stub
-- 
Sent from my DroidX with K-9 Mail. Please excuse my brevity.



> Andrew Wood <[email protected]> wrote:
> 
> Can anyone point me in the direction of this 'paint on' insulating material please. Or at least give me a name of what its called. Ive never seen anything like that before._____________________________________________
> | REPLYING: address your message to [email protected] only. | Multiple-address or CCed messages may be rejected. | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub | OTHER HELP: http://evdl.org/help/ | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
> ...


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## EVDL List (Jul 27, 2007)

Thanks Chris. Not fully decided whether to paint something like that on the inside of the box or use phenol sheet. I might use that stuff anyway to 'glue' the phenol to the alu box.

What thickness of aluminum do you think. I was thinking 3mm when I was thinking of steel but if I use aluminum it might need to be thicker. Total weight of whats going inside will be about 40kg.

Impact resistance isnt so critical as its going inside a rigid area of the spaceframe which should offer good protection.

Also with the thickness of phenol sheet used as an insulating layer inside. do you think 3mm is adequate or perhaps a couple of mm thicker?

Thanks
Andrew

Sent from iPhone



> Chris Stephens <[email protected]> wrote:
> 
> > http://www.edesignaudio.com/index.php?cPath=1_24
> >
> ...


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## EVDL List (Jul 27, 2007)

Im no expert by far but have done a little welding and such. No idiot I guess I could say. 
Anyway, by my guestimation, 3 mm aluminum is around 10 or 11 gauge and seems about right If you use say 1/2 inch bead roller every foot or so and don't. Try to span more than 3 feet.


-- 
Sent from my DroidX with K-9 Mail. Please excuse my brevity.

Andrew Wood <[email protected]> wrote:

Thanks Chris. Not fully decided whether to paint something like that on the inside of the box or use phenol sheet. I might use that stuff anyway to 'glue' the phenol to the alu box. What thickness of aluminum do you think. I was thinking 3mm when I was thinking of steel but if I use aluminum it might need to be thicker. Total weight of whats going inside will be about 40kg. Impact resistance isnt so critical as its going inside a rigid area of the spaceframe which should offer good protection. Also with the thickness of phenol sheet used as an insulating layer inside. do you think 3mm is adequate or perhaps a couple of mm thicker? Thanks Andrew Sent from iPhone


> Chris Stephens <[email protected]> wrote: > http://www.edesignaudio.com/index.php?cPath=1_24 > > Not sure if that's what you are after or not but it worked great on my ice mustang as sound deadner. > > Stub > -- > Sent from my DroidX with K-9 Mail. Please excuse my brevity. > > Andrew Wood
> <[email protected]> wrote: > > Can anyone point me in the direction of this 'paint on' insulating material please. Or at least give me a name of what its called. Ive never seen anything like that before._____________________________________________
> > | REPLYING: address your message to [email protected] only. | Multiple-address or CCed messages may be rejected. | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub | OTHER HELP: http://evdl.org/help/ | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: http://lists.sjsu.edu/mailman/private/ev/attachments/20110330/9ff19502/attachment.html >_____________________________________________
> > | REPLYING: address your message to [email protected] only. > | Multiple-address or CCed messages may be rejected. > | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > | OTHER HELP: http://evdl.org/help/ > | OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev_____________________________________________
> ...


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## EVDL List (Jul 27, 2007)

Need some way of fixing phenolic sheet to inside of box

Sent from iPhone



> Lee Hart <[email protected]> wrote:
> 
> > On 4/3/2011 8:18 AM, Andrew Wood wrote:
> >> Its not for electrical insulation. I just want a glue which can
> ...


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## EVDL List (Jul 27, 2007)

Assuming you are joining aluminum and phenolic, I would suggest a 
methacrylate epoxy. Not just any epoxy. Specifically a methacrylate 
epoxy.




> Andrew Wood wrote:
> 
> > Need some way of fixing phenolic sheet to inside of box
> >
> ...


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## EVDL List (Jul 27, 2007)

Electronic type RTV (non-corroding)
Dow Corning 162 Noncorrosive

You can tell if it is the right stuff if it doesn't stink like vinegar.

Bill D.

At 11:17 AM 4/7/2011, you wrote:
>Need some way of fixing phenolic sheet to inside of box
>
>Sent from iPhone
>
>


> Lee Hart <[email protected]> wrote:
> >
> > > On 4/3/2011 8:18 AM, Andrew Wood wrote:
> > >> Its not for electrical insulation. I just want a glue which can
> ...


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