Dual Battery modification?

[lolder]

I have read that our FFH is only good for up two miles in EV mode, so a second battery charged over night would make that 2 mile stretch seem short?

You are talking about a plug in hybrid. Making a plug in out of a non-plug-in makes no economic sense particularly when the manufacturer makes one. The HVB is an expensive, fragile, dangerous device that would be very difficult to add to. The software is different and the onboard HVB charging from AC is a whole additional system. This is not remotely like paralleling two 12 vdc batteries.

 

There are two conflicting operations involved here. Contrary to popular belief, it is NOT desirable to maximize EV use in a hybrid because the EV cycle of generating-charging-discharging-motoring has more loss in many cases than driving the car through the gears to the wheels, particularly at higher speeds. All the hybrids have about a 1.5 Kwh HVB which is sized to provide a significant recovery of braking energy and provide cyclic use of EV at lower speeds all within a very narrow range of HVB charge which provides long battery life. Larger HVBs are not an advantage as it adds only cost, weight and reduced luggage capacity.

 

Plug in hybrids are an engineers nightmare. They try to find the middle ground between pure plug-in electrics range anxiety and hybrids. They don't do that very well and their price premium has been more unrecoverable than hybrids.

 

If you drove 20 miles a day with a plug in hybrid, you would only save $0.75 a day over the hybrid. For a year of commuting that would be less than $200. That's with electricity at $0.12/kwh and gas at $3.00/gal and doesn't include amortizing a home charging station. If you got your electricity free it would only save $400.

[Waldo]

It still sounds to me like what you're trying to do is convert your hybrid into an Energi. Given that the Energi gets around a $6000 tax advantage, you are trying to build an Energi for $6000 less than Ford is already doing it. i really don't see how you will be successful.

[OneSpeed]

Thanks for the input.

Like I said, I am a hot rod guy and new the the hybrid so I want to learn.

[corncobs]

Thanks for the input.

Like I said, I am a hot rod guy and new the the hybrid so I want to learn.

Whatever you end up doing be careful the 300+V DC of the HVB hurt a lot more than your average 110V outlet. ;)

 

Oh and keep us up to date if you don't mind.

[lolder]

You mentioned that you had a budget for the car so you have a concern for money like most of us. I suspect any changes to the drive train would void the warranty. This would not be a car that would take kindly to things like aftermarket performance chips.

[Raymond J Ramirez]

Thanks for the input.

Like I said, I am a hot rod guy and new the the hybrid so I want to learn.

I am a 2014 Ford Fusion Hybrid owner and an Electrical Engineer. If you want to learn more about the Hybrid system and the battery, go and buy the Ford Service manual on DVD for the Fusion Hybrid/ Energi models (both are on the same DVD). You can get it at eBay for about $50. Then read and see the difference between them. If you really wish to learn more, watch the Weber Auto YouTube videos about the Fusion Hybrid battery disassembly: https://www.youtube.com/user/WeberAuto

 

I have done my part of investigation, and the only possible "upgrade" which I can see that can be done on the Hybrid is to add another Hybrid battery pack in parallel to double the current and power rating (to 3 kWh). This involves removing the Hybrid battery, modifying the connections, replacing the original Hybrid battery, and mounting the new battery in the free space of the trunk. The new battery will lose its monitoring. anyway

 

But adding an on-board charger is almost impossible. You can try an external DC charger and wire up a connector in the trunk for it. Even if you do get an Energi battery system, you cannot just do a "swap" and expect it to work. The system change affects the general driver interface programming more than any layperson can do.

 

As many here have recommended, it is easier and perhaps cheaper to trade in the Hybrid for a Energi. You do lose trunk space and the pass through that the Hybrid has because the Energi pack is taller, adds more electronics (the AC-DC charger), and uses a larger 25 Ah cell versus the 5 Ah cell in the Hybrid. Try leasing the Energi for a year, test it, and then decide what to do.