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Discussion Starter · #21 · (Edited)
Time to try public charging with a Type 2 EV AC plug.


We have a few charging points at the leisure centre I visit most days so I'm going to try plugging in at one of those.

I basically bought a Type 2 plug with a Blue Commando 16A socket on the end.

Going to investigate putting the buddy pack under the fake floor in the boot now where the big piece of polystyrene normally lives.
I should be able to make a up a bracket that buddies onto the bolts that hold the OEM battery cover on.
Or I might even take that off to get a bit more depth and access to the four big bolts.

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Quite a bit of space here with poly removed.
 

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Free Type 2 charging at my local leisure centre! They have four bays and hardly ever used.
Not quite a PHEV yet but it's a useful boost.. :)

View attachment 68462
Man! I Love this!

A flip down hinge on the bottom of the Licence plate at it will almost look like it was made for it.

There is a lot of room back there, at least with the US model. Not sure about others with your fancy parking sensors (just a little jealous) 😁
 

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Discussion Starter · #24 · (Edited)
Time to work out the optimum battery pack for the easiest and safest buddy pack install.

Voltage...

If we are not going to convert power back and forth using a buck converter we have to carefully match the voltage of our pack to the range the OEM system will accept.

The OEM setup uses 40x 5ah LiPo cells in series with a theoretical voltage range of 3.2 - 4.2V per cell.
In practice Honda only uses a small window of the capacity and a very narrow working voltage range of about 3.4 - 3.9V

The balanced total pack voltage is directly correlated with the SOC the car displays and uses to determine IMA function.

155V and above gives 80%SOC and no regen.
152V gives 75% SOC and allows regen braking and on the overrun.

168V would be absolute maximum pack voltage and that would be 4.2V per cell.
So we really need a pack whose voltage maxes out at about ~4.1V per cell or 164V.

Ideally we would like to hold the voltage steady at 152V at all times but that's much more difficult without electronics to help out.

Capacity...

Probably 50ah or higher to make it worthwhile..
With a 164V x 50Ah pack that gives us about 8kwh of capacity.
Using a suitable charger and a 7.4kw EV point that gives me a ~1hr recharge time.

My ancient test pack is barely 3kwh.


Chemistry...

Probably Lifepo4 or Lto rather than LiPo!
LiPo is light and powerful but it fails dramatically when it does fail. The other two are a lot safer.

So if we go LifePo4 they have a nominal voltage of 3.2V per cell.
Charging them at 3.5V will get them to ~95% SOC

So 48 Lifepo4 cells gets us into the right ballpark. :)
It's a nice even number as well to make a rectangular pack.

48 x 3.45V charge = 165.6V (Within our OEM pack voltage tolerance range)
48 x 3.2V nominal = 153.6V (This is the voltage they will spend most of the time at.)

So bottom line for now I will build a 48 x 50Ah Lifepo4 Cell pack for a proper PHEV test.

Now there are millions of cheap batteries on Aliexpress and I shall probably give a set of them a go...


Weight...

48 x 50ah Lifepo4 is approx 50kg.
 

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Crazy thought, but could that connector be put where the fuel door is on the other side of the car? Doesn't the fuel come on different sides in different markets? Even if it does not, a good body shop or skilled person could graft a "Fuel" door to the other side. Just a crazy thought, but this is amazing work. Most of the stuff in the styrofoam holder we not need, as we have no spare anyway. I would rather have more range than the weight of the jack etc.

Man! I Love this!

A flip down hinge on the bottom of the License plate at it will almost look like it was made for it.

There is a lot of room back there, at least with the US model. Not sure about others with your fancy parking sensors (just a little jealous) 😁
 

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Discussion Starter · #26 ·
The rear hatch rubber seal has enough flexibility to simply put a cable through as you can see in the pictures.
It doesn't damage it. Adding the flip up door/licence plate etc might be cool but it's not really necessary.
 

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Discussion Starter · #27 · (Edited)
There will be a six week timeout on this project as I'm away on a Canadian road trip.
However I will try and order the Lithium cells before I go so they can be chugging across on the slow boat from China.

I can report however I am using the free plugin facility at the local gym each day.
My mpg is creeping up as the car does virtually no background charging on my local trips.. (y)

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Discussion Starter · #30 · (Edited)
@creambun A long time ago in a galaxy far far away......... Nearly twenty years ago now. An earlier EV project.

Realistically in the UK solar on a CR-Z roof might net you 100w or so in the summer.
It's not cost effective here.. I had at least double a CR-Z roof area on my old van.

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I have acquired 52 x 50ah Lifepo4 cells in the UK and am picking them up on Thursday. (y)

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So might be a little progress before I go on my trip on Monday.
 

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Discussion Starter · #31 ·
Someone did do some testing on one of these cells in the UK.


But they did not use the remote voltage sensing function on the electronic load which is odd.
So the voltages recorded are skewed by the voltage drop in the wires to the cells under the 25A load.

I'll test one with mine when they arrive.
 

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Discussion Starter · #32 · (Edited)
Hmm something else has occurred to me.. :devilish:

I get free 7.2kw charging at the gym/leisure centre.
I'll soon have a roughly 7.2kwh battery pack.

I have a simple charger/pack connection in the rear of the car.
So can I run my house from the pack by plugging in a suitable inverter/converter?

Go to gym, plug in car, workout then go home with 'free' charged pack.
Use pack to power house that day/night.
Rinse and repeat as often as I want LOL. ;)

'Starts Googling for a suitable inverter.'

Looks like I need one of these..


Of course this also opens up the possibility of running the house from the car with the engine and IMA actually running.
So like a portable Genset for when the power goes out in the UK this winter.

Just let the car tickover and command the IMA to regen to keep the pack charged.
 

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can we use another hybrid battery as a buddy pack like a jazz , CRV , or TOYOTA PRIUS from the scrappy might be a bit cheaper i wonder which has a similar voltage

Honda Insight is 270 volts is this too much ?
 

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So discharged the OEM Lithium pack on my drive around to 20% and the assist disable point. ~3.20V per cell
Plugged it in and charged back up at home using the mains no issues. (y)

20-80% SOC took a laughably short ten minutes :LOL: at 2kw grid draw and 12A charge rate.
Total electricity consumption was about 0.35kwh to charge from flat to full and charger cut off at ~4.00V per cell.

If we assume about 90% mains to battery charge efficiency then we get about 300wh into the pack between 20-80%.
A standard car would not be able to discharge to the levels I did with the manual control so the useable power would be quite a bit lower say 200wh.

The capacity of the OEM pack really is very feeble. It desperately needs a buddy!
That's this weekends project. ;)

3 x LTO 1.1kwh blocks to give ~3000wh or ten times my current capacity!!

View attachment 68263

100mpg here we come.. :p

Edit. Also charged up the scrapyard OEM Lithium pack with the mains charger after checking cells with OBDIIC&C.
It has 52% useable capacity. All nicely balanced and back in cool storage now.

So if anyone in the UK/EU needs either a Nimh or Lithium OEM pack I have a good one of each available.
price on the spare oem pack please
 

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Discussion Starter · #35 · (Edited)
can we use another hybrid battery as a buddy pack like a jazz , CRV , or TOYOTA PRIUS from the scrappy might be a bit cheaper i wonder which has a similar voltage

Honda Insight is 270 volts is this too much ?
@creambun I have sent you a conversation

You can do almost anything with the knowledge and equipment.
Most hybrid battery packs could be made to work in some form or other.
But each would require a different bespoke solution/implementation/hardware/electronics etc etc

Nimh packs contain little stored energy and are much heavier.
Lithium really is the way to go but it needs careful management.

New 48 x 50Ah Lifepo4 cells on test...


EDIT
The first two cells I've tested gave 54ah capacity when charged to 3.6V and discharged to 2.5V using a constant current 25A (0.5C) load.
Slightly better than the expected/rated 50ah.

Hmm. Can't find my Orion2 BMS. :unsure: Might have lent it out, but buggered if I can remember who too???
 

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Discussion Starter · #36 · (Edited)
5 x 50ah cells tested so far, all over 54ah. (y)

From my testing so far with the old pack and manual IMA control, 25 amp discharge (assist) gets you ~30mph on flat terrain with the engine pegged at ~100mpg.
So theoretically this new pack will provide approx ~60 miles at 100mpg over ~2hrs.

That's about 3.8kw (5hp) of constant assist. 154V x 25A = 3850 watts.

Of course if you have a shorter distance to travel you can use more assist and push the mpg numbers higher for a shorter period.
 
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