Is Adding a 2nd Battery Pack feasable?

[Ianmark]

I have a 2014 C-Mac Energi I just got a couple of days ago. It has 192km on the clock and it only needs some paint work around the wheel arches. I had another Energi in the summer for a week as I bought it for resale and I loved it. I knew about the 23k  range ans I am fine with it, but as with everything, I try to improve what I have.

 

Is it possible to get a 2nd battery pack and run 2 to increase electric only range? I got the car for $5200 (CDN) and it has Active Parking Assist, full leather, power liftgate, GPS, so if I were to get a good second hand battery, I'm still ahead of the game.

 

I don't care about trunk space, so adding another one should fit. The thing I don't know about are the controllers and voltage regulators and the like. Will the car accept the 2nd battery pack?

 

I am just investigating this, so I really do not know anything about it, so I am looking for a little info.

 

Thanks for the help,

Ian

Edited February 24, 2022 by Ianmark

[Nicky]

That's a great question. I don't see why not. If you put the batteries in parallel you're only increasing your capacity not the voltage. But even with Ford I believe they have 300 volt Max rated system. So even if you increase the voltage you're still okay up to that amount. I want to do the same thing in my hybrid. All I want to do is increase my battery storage capacity so I can keep it on electric mode for longer during errands around town. It also be awesome if I can increase the voltage so the electric motor is the main drive and the engine is the range extender. I've looked all over online and have found many people doing many different unique things. I do plan on getting an extra pack and figure out a way to make it work in my c-max and seeing what happens.

Edited August 20, 2022 by Nicky
Spelling and clarification

[cr08]

On 8/20/2022 at 12:34 PM, Nicky said:

That's a great question. I don't see why not. If you put the batteries in parallel you're only increasing your capacity not the voltage. But even with Ford I believe they have 300 volt Max rated system. So even if you increase the voltage you're still okay up to that amount. I want to do the same thing in my hybrid. All I want to do is increase my battery storage capacity so I can keep it on electric mode for longer during errands around town. It also be awesome if I can increase the voltage so the electric motor is the main drive and the engine is the range extender. I've looked all over online and have found many people doing many different unique things. I do plan on getting an extra pack and figure out a way to make it work in my c-max and seeing what happens.

 

I doubt this will work out as you want it to. There's a LOT of electronics and programming involved that expect a given battery capacity and voltage. Also charging is an issue with cell balancing involved. The vehicle would need to be made aware of the second pack that it needs to manage. Even moreso, expecting to push more 'voltage' into the drive motor is out as that is all on the inverters and vehicle programming. Short of being able to reverse engineer and reprogram that (and likely replacing some electrical components in the inverter), you aren't getting anywhere on this one.

 

Not to say I'm dissuading you from trying, but these systems are a LOT more complex than you're implying.

[homestead]

I think if you connect them in parallel there will be current flowing between the two packs.

How about running one pack down to empty and then just switching the hot line to a 2nd pack that is fully charged.

You would also have to switch between packs when charging.

 

[SnowStorm]

The answer to this thread's title is NO.  I wouldn't think of trying this even though (sorry to say all this) I'm a professionally licensed engineer with a Masters Degree in EE and decades of engineering work experience including years with VFDs operating at twice the voltage and many times the power.  These hybrid car systems are nothing like working with a couple of 12V lead-acid batteries in series or parallel.  Theoretically, most anything is "possible" but this one isn't feasible - too many unknowns, too much complexity and too great a danger to both you and the car.  Much simpler, safer, and likely cheaper to get a used Leaf or Volt.

[fbov]

On 8/20/2022 at 12:34 PM, Nicky said:

I don't see why not. If you put the batteries in parallel you're only increasing your capacity not the voltage.

It's not a flashlight. You can hurt yourself at these voltages. 

On 8/20/2022 at 5:54 PM, homestead said:

and then just switching the hot line to a 2nd pack

Do you still think, after all these years, that you can "just switch the hot line?"

 

First, you'd have to get dressed for it. 

 

Then you'd need  a second voltage matching circuit. Switching 200+VDC with mechanical contacts causes an arc every time you open and close the switch. The arc destroys the contacts, so the switch fails. You'd need to add a second voltage matching circuit to your added pack, to bring the contacts up to voltage before closing them. 

 

Now, where are you going to put it?

 

[homestead]

fbov, You are describing all the steps to go through in designing a switch circuit and the need for a place to put the switch, So yes it is possible but not for the the lay-man.

Too much work to make it worth it.   If you haven't worked with high voltage before not recommended.

You could hire an engineer to design/fabricate a switch for you but the costs would be prohibitive.

But, people do crazy stuff like this all time and some of them actually get their diy projects working.

More power to them.

 

[SnowStorm]

On 8/20/2022 at 5:54 PM, homestead said:

just switching the hot line

BTW, there isn't a "hot line" (singular).  Both sides of the HV battery are un-grounded "hot" lines.  Both lines are monitored for resistance to ground - IIRC, you can read the values in Forscan.  Again, nothing like a 12V car battery!

 

On 8/22/2022 at 3:39 PM, fbov said:

First, you'd have to get dressed for it.

Great video.  This guy can give you quite an education on hybrid stuff.

[fbov]

On 8/23/2022 at 9:11 AM, SnowStorm said:

This guy can give you quite an education on hybrid stuff.

Indeed. I am very happy to see he's making video's again... I'd be ecstatic if I had a Mach E.