Additional Battery Project - Possible Extra 40 kwh

[jimbo69ny]

The seller only has one for sale. So I found the part number and searched for that. FBA-12G12H1BX

Found a few more that were significantly cheaper!
https://www.ebay.com/sch/i.html?_from=R40&_sacat=0&_nkw=FBA-12G12H1BX&_sop=15

Update:
I purchased 2 of these fans. Thanks!
https://www.ebay.com/itm/NMB120mm-F...396a6f96c:g:s~sAAOSwjyhaTFZI&autorefresh=true
Seller accepted my offer of $20 for 2.

 

[smkettner]

Ive heard that it is better to have them suck air out than push it in. You think that is true? I wanted to have them blow in so I could put a heater in front of them at some point.

More important to have good baffling to get the air to move across all cells. May need some foam dividers etc to to build a path. Air across the top leaves most cooling to convection. With so much unknown consider a temperature sensor that you can move around.

 

[jimbo69ny]

Ive heard that it is better to have them suck air out than push it in. You think that is true? I wanted to have them blow in so I could put a heater in front of them at some point.

More important to have good baffling to get the air to move across all cells. May need some foam dividers etc to to build a path. Air across the top leaves most cooling to convection. With so much unknown consider a temperature sensor that you can move around.

The original plan for the box included baffles but I had to remove them in order to fit the 9th module. There wasn’t enough space.
I do have a temperature sensor/switch on its way. A link is in the first post under purchased items. I also plan to get an infrared temperature sensor at some point so I can watch for hot cells.

 

[Philly RAV4 EV]

It is better to pull air thru the box than pushing air in

 

[Philly RAV4 EV]

You can also install an adjustable snap disc thermostat for inside the box so the fans come on and off automatically

 

[jimbo69ny]

It is better to pull air thru the box than pushing air in

Thank you for confirming. Ill install these fans so they pull air out.

You can also install an adjustable snap disc thermostat for inside the box so the fans come on and off automatically

I'd have to google what a snap disk thermostat is but in my previous post I mentioned that I have a temperature switch on its way. So I do plan on using a thermostat and switch.

 

[smkettner]

The battery stacks can be the baffles. Build the nine stacks with empty slots alternating on each side or top to bottom etc. Then us foam to seal around the edges.

 

[jimbo69ny]

We had an unseasonably warm day here in NY so I took the opportunity to run the power wires.

I picked up XLE EXRAD 2 gauge shielded wire rated at 255 amps. That should be enough because neither pack will see full amperage. The packs will be in parallel. I am connecting them to my Jdemo box contactors. I may have to upgrade Tony's 2 gauge wires that run from the Jdemo to the battery pack. I dont know what his cables are rated to but the EXRAD wires are the highest rated wires I have seen. Ill have to see what kind of amperages are there once its all done. I also ran a 8 gauge wire for 12v power.
http://evwest.com/support/Shielded_Battery-Irradiated_XLE.pdf

 

[betatest3]

Hmm, this looks interesting...

Will this battery work seamlessly with the RAV4 EV systems? By that I mean, will it charge up normally from J1772 or JdeMO?
If you get this working well, it could be something that can be sold as a kit or something. Maybe Tony Williams would be interested in carrying something like this at QuickChargePower, in addition to JdeMO, you could get a range extending battery.

 

[jimbo69ny]

Hmm, this looks interesting...

Will this battery work seamlessly with the RAV4 EV systems? By that I mean, will it charge up normally from J1772 or JdeMO?
If you get this working well, it could be something that can be sold as a kit or something. Maybe Tony Williams would be interested in carrying something like this at QuickChargePower, in addition to JdeMO, you could get a range extending battery.

Yes, it should. My pack is going to run in parallel with the main pack so charging with j1772 will definitely charge both packs. I am not positive if Tony has any kwh limitations in his Jdemo programming but it should charge with jdemo too. If he does have some kind of limits in place I am assuming unplugging and restarting the process would continue charging.

Tony is also working on his own range extending pack. I think he wants to use Tesla Smart Fortwo packs but he hasn't told me anything about his plans.

I dont plan on offering this as a kit. I am posting my process on here so anyone can follow it and do it if they want to. I'm not looking to make a business of this or make any money on it.

 

[jimbo69ny]

I decided to redesign my whole pack. The lower cargo area isn't quite large enough for the pack I want to put in so I've decided to cut the floor of the cargo area out and weld in a new box. Its going to be a bit of work but it will give me more room for my battery pack. The battery box is going to feature some safety features that make the extra work worth it.

Here is my new module design. There will be 9 of them total. Total pack will be a 92s32p configuration

The new box will have a square bottom instead of the previous box design which had an angled bottom to follow the OEM floor.
This is the box before the dividers.

Here is the box with dividers. They will direct airflow up and down through the pack but also give the box strength. Another reason I wanted them is because 18650 cells can be volatile. If one goes into a thermal run away it will trigger the ones around it. Having each module isolated from other packs will help slow the explosion.

Another photo of the pack.

It will be air cooled. I purchased 3 104 cfm 12 volt fans that move a surprising amount of air. They will suck air out of the pack. Air will enter on the opposite side of the box through an opening of equal size to the fans.

The plan next is to take this box and my car to my welder to see what this is all going to cost me. I want to have it all done in aluminum to save weight. Hopefully the price doesnt bust the project....

 

[miimura]

I decided to redesign my whole pack. The lower cargo area isn't quite large enough for the pack I want to put in so I've decided to cut the floor of the cargo area out and weld in a new box. Its going to be a bit of work but it will give me more room for my battery pack. The battery box is going to feature some safety features that make the extra work worth it.
...
The plan next is to take this box and my car to my welder to see what this is all going to cost me. I want to have it all done in aluminum to save weight. Hopefully the price doesnt bust the project....

Can you explain this a little more? It sounds like you're going to cut out the steel sheetmetal that forms the under-floor compartment. If you build the new box out of aluminum how are you going to structurally support the weight and make a water-tight seal between the aluminum and steel?

 

[jimbo69ny]

I decided to redesign my whole pack. The lower cargo area isn't quite large enough for the pack I want to put in so I've decided to cut the floor of the cargo area out and weld in a new box. Its going to be a bit of work but it will give me more room for my battery pack. The battery box is going to feature some safety features that make the extra work worth it.
...
The plan next is to take this box and my car to my welder to see what this is all going to cost me. I want to have it all done in aluminum to save weight. Hopefully the price doesnt bust the project....

Can you explain this a little more? It sounds like you're going to cut out the steel sheetmetal that forms the under-floor compartment. If you build the new box out of aluminum how are you going to structurally support the weight and make a water-tight seal between the aluminum and steel?

Yes the plan is to cut the think sheetmetal floor out. Its pretty wide open all around it under the car. I might even lower the pan an inch.
I will leave the details up to my welder. The whole area is a crumple zone but I want to make it as strong as we can.

 

[jimbo69ny]

Conctactor and master switch boxes are almost done.

Also, I found a lead on LG MJ1 3500 mah cells for $3.80 each today. Best deal I have found so far.

 

[ph2]

Looks very tidy... I don't see an isolator for the 12v on side of things. Make sure you put one on the shunt, at minimum, to filter any high voltage/faults out, lest you want EV System Error messages and charge failures. They are fairly easy to find on the free two-day shipping site online; there is one rated at 1A that would likely suffice.

 

[jimbo69ny]

Looks very tidy... I don't see an isolator for the 12v on side of things. Make sure you put one on the shunt, at minimum, to filter any high voltage/faults out, lest you want EV System Error messages and charge failures. They are fairly easy to find on the free two-day shipping site online; there is one rated at 1A that would likely suffice.

And isolator for the 12 V side? I don’t get it

 

[ph2]

Yes, the ammeter may cause a fault on the car's electrical isolation/interconnect system if not isolated on its power supply; especially during charging.

Use something like this... but make sure that it provides adequate current for your ammeter (should be listed in your ammeter specs).

1212CS DC-DC 12V (2Watt) Isolated Power Module. Ideal for 12V system
https://www.amazon.com/dp/B0043BHFS2/ref=cm_sw_r_cp_apa_O6-OAb8F2PNYV
There are larger available if you look around.

Also, for the high voltage sense lead, you might consider putting a fuse in-line on in the event it ever develops a short and make sure it has 600v rated insulation or higher.

 

[jimbo69ny]

Yes, the ammeter may cause a fault on the car's electrical isolation/interconnect system if not isolated on its power supply; especially during charging.

Use something like this... but make sure that it provides adequate current for your ammeter (should be listed in your ammeter specs).

1212CS DC-DC 12V (2Watt) Isolated Power Module. Ideal for 12V system
https://www.amazon.com/dp/B0043BHFS2/ref=cm_sw_r_cp_apa_O6-OAb8F2PNYV
There are larger available if you look around.

Also, for the high voltage sense lead, you might consider putting a fuse in-line on in the event it ever develops a short and make sure it has 600v rated insulation or higher.

So you think that the 12 volt power going to the board of the shunt is going to somehow cause issues with the 12v system in the car? Ive seen other people using this monitor and havent heard that before.

I do have fuses. I have one under the hood where I get power from the Jdemo and a second one at the additional battery maintenance switch. Ill post photos when I get it done. Its snowing like crazy and I have a newborn at home but Ill try to get outside to do it today. I usually end up working late at night when mom and the kid go to bed around 8.

 

[jimbo69ny]

Just got them installed. I am now ready for a battery.

I left one of the leads long by mistake. Eventually it will be covered by the false floor. So far thats my only boo boo. Which is good because I am still alive.

 

[jimbo69ny]

Instead of updating the first post I decided to post an update here. This has been an amazing project so far and I am learning a lot. I dont have a lot of money into it so far but I do have a fair bit of time invested. I am nervous to take the big step of purchasing the 18650 cells. As you will see in my following post its going to cost me around $11,300 for the cells. That's a lot of money to lose if I **** up......

Goal:
I'd like the largest battery possible but I only want to sacrifice the lower storage space in the rear cargo area.

Time frame:
I want to get it done by NDEW in September 2018

Battery Plans:
I plan on using brand new lithium ion LG MJ1 18650 battery cells. Each cell is rated at 3500 mah and 10 amps constant. Here they are, https://liionwholesale.com/products...at-top-wholesale-discount?variant=11564550916
I can fit 9 modules in a vertical formation in the lower cargo area if I cut out the floor pan. I plan on matching the OEM pack to keep voltage the same. The OEM pack is 92s48p, I am planning on building a 92s32p pack. I can fit 320 cells in each module, 2,944 total cells in this configuration. The floor of the cargo area will be raised about 2 inches.

Battery Box:
I'll hire a welder to build me an aluminum battery box. I plan on mimicking the details Tesla incorporated into its pack. Each of the 9 modules will be as isolated from the other packs as much as possible. ¼” Aluminum will be used on the outer walls. Inside I will have baffles to direct airflow in order to cool the cells. I will use mica sheets to insulate the interior baffles. The baffles will also give it some structural rigidity in case I am rear ended. I have also looked into a fire extinguisher system using Firebane which super cools cells that are going thermal. Lastly, I want to try to incorporate Tesla’s vent plugs if I can get my hands on any.

Heating/Cooling:
I am not planning on installing a heater. I am going to see how it goes. If I need to add one later I will go with a PTC heater.
To circulate air through the baffles I have 3 fans on the right sid of the box sucking air out of the box. I was told by my engineer brother that 3 or even 6 fans might not be enough. Time will tell.

Capacity:
(Assuming 92s32p)
If each cell is 2600 mah, that would be 83,200 mah or 83.2 AH (2600 x 32)
386 volts x 83.2 AH = 32,115.2 WH aka 32.1 kwh battery capacity

If each cell is 3400 mah, that would be 108,800 mah or 108.8 AH (3400 x 32)
386 volts x 108.8 AH = 41,996.8 WH aka 41.9 kwh battery capacity

Minus 10% as unusable =
28,903.68 WH aka 28.9 kwh battery capacity
37,797.12 WH aka 37.7 kwh battery capacity

Range:
Weight of car / 10 = watt hours per mile
Rav = 4500lbs
4500lbs / 10 = 450 wh per mile
28,903.68 kwh / 450 wh per mile = 64.2 miles with 2600 mah cells
37,797.12 kwh / 450 wh per mile = 83.99 miles with 3400 mah cells

OEM rating would be:
41,900 / 450 wh per mile = 93.111 miles with OEM 2600 mah cells
41,900 / 350 wh per mile = 119.714 miles with OEM 2600 mah cells *more realistic*

Theoretical realistic range with additional pack:
28,903.68 / 350 wh per mile = 82.58 miles with 2600 mah cells
37,797.12 / 350 wh per mile = 107.99 miles with 3400 mah cells

Plus existing range from 41 kwh OEM pack!
119.714 miles + 82.58 miles = 202.29 Miles with 2600 mah cells
119.714 miles + 107.99 miles = 227.7 Miles with 3400 mah cells


Weight:
Batteries:
92s32p = 2,944 cells
2,944 x 49 grams = 144,256 grams aka 318 lbs
Box = 100 lbs ish?
Body work = 60 lbs ish?
Other = 100 lbs ish?
578 lbs total?

BMS/System monitoring:
I haven't explored this yet so I dont know what options are out there. I would like a unit with a display that shows voltage, temp, amp hours, etc of the batteries.

Cost:
92s32p = 2,944 cells
2600 mah $2.80 x 2,944= $8,243.20
3400 mah $3.80 x 2,944= $11,187.20
Plus $100 for shipping

Price per kwh:
Only for the cells. No box or system parts.
2600 mah - $8,343.20 / 28.9 kwh = $288.69 per kwh
3400 mah - $11,287.20 / 37.7 kwh = $299.40 per kwh!

Parts To Date:

Contactors $61
https://www.ebay.com/itm/Tyco-TE-Relay-EVC-500-AAANAM-12-24-V-500A-High-Voltage-Automotive-Main-Contactor/142386677471?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649
Inertia Switch off ebay $13
20 Dead 18650 cells off ebay $13
2 - 400v 250 amp fuse off ebay $15 each
(3) Panaflow high speed fan NMB120mm FBA12G12H $20
https://www.ebay.com/itm/NMB120mm-FBA12G12H-1BX-103-8CFM-High-Speed-PC-Computer-Case-Fan/152851380588?hash=item2396a6f96c:g:s~sAAOSwjyhaTFZI&autorefresh=true

3 - Temperature fan control modules $2
https://www.ebay.com/itm/W1209-12V-50-110-C-Digital-Thermostat-Temperature-Control-Switch-Sensor-Module/112704697471?ssPageName=STRK%3AMEBIDX%3AIT&var=413176014560&_trksid=p2057872.m2749.l2649
Gigavac Hbd41AA $49
http://www.gigavac.com/shop?title_op=%3D&title=hbd41aa1
3 - M22x 1.5 cable glands 5 pack for $8.85
https://www.amazon.com/gp/product/B071VT8NLM/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

Digital energy monitor $27.90
https://www.ebay.com/itm/400V-300A-DC-Digital-Voltage-Meter-Ammeter-Voltmeter-Capacity-Coulomb-Counter/352245023429?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649


2 Gauge shielded EXRAD wire from iewc. (EXRAD02-XLEOBS-5) 35 feet $6.25/foot. Purchased 35 Ft = $218.75 + shipping
http://evwest.com/support/Shielded_Battery-Irradiated_XLE.pdf

Electrical box $13.49
https://www.amazon.com/gp/product/B071FKFK6W/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1

Crimp ring terminals $20.02
https://www.amazon.com/gp/product/B073FB2Y4S/ref=oh_aui_detailpage_o08_s00?ie=UTF8&psc=1

Automotive 12v relays $11.99
https://www.amazon.com/gp/product/B00RWV470O/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

8 Gauge wire $9.99
https://www.amazon.com/gp/product/B01LY5N276/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

Fuse panel $9
https://www.amazon.com/gp/product/B00QMTAZ1W/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

Ground distribution block $4
https://www.ebay.com/itm/1x-4-Way-Car-Audio-Solar-Amp-Power-Ground-Cables-Splitter-Distribution-Block-4ga/292463871751?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

Lots and lots of 18650 cell holders $100-$200ish
https://www.amazon.com/gp/product/B01HQB085C/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1

Aux battery switch $20
https://www.ebay.com/itm/CH4x4-Toyota-Small-Push-Switch-Aux-Battery-Symbol-White-LED/202244345319?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

Misc wire $12
https://www.ebay.com/itm/16-AWG-Gauge-Primary-Wire-Car-Copper-Made-in-the-USA/192255561445?ssPageName=STRK%3AMEBIDX%3AIT&var=492184468583&_trksid=p2057872.m2749.l2649

12 volt fuse holder $2
https://www.ebay.com/itm/4-6-8-Gauge-Agu-in-line-Fuse-Holder-Gold-Plated-with-Clear-Housing-for-Car-Amp/112819785637?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

¾” and 11/2” shrink wrap with adhesive around $20