Leafhacking Battery Mod Gives Extra Range, But At What Cost?

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Enginer Supplemental Leaf Battery Pack

Enginer Supplemental Leaf Battery Pack

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Like early-adopters of any new technology, the first owners of electric cars like the 2012 Nissan Leaf and 2012 Chevrolet Volt have already proven that they like to hack their plug-in cars to improve features, charging times and even performance. 

The latest leafhack, from plug-in hybrid battery specialists Enginer, aims to increase the range of the 2011 and 2012 Nissan Leafs by installing a supplemental lithium-ion battery in the bottom of the trunk. 

But with the 2013 Nissan Leaf rumored to have better range and winter performance, what’s the real cost of hacking your Leaf in this way, how easy is it, and would you be better to get a 2013 model instead? 

How it works

2011 Nissan Leaf SL

2011 Nissan Leaf SL

Enlarge Photo

According to Enginer’s own website, the leafhack involves adding its own 4 kilowatt-hour, 8 kWh, or 12 kWh, 48-volt lithium-phosphate battery pack, charger and high-voltage DC-to-DC converter into the trunk of a stock leaf. 

Originally designed by the company to convert regular Toyota Prius hybrids into plug-in hybrids, the system’s DC-to-DC converter then takes 48-volts from the supplemental battery pack and steps the voltage up to 390-volts. 

The resulting 390-volts is then used to provide a continuous, low current trickle charge to the Leaf’s stock 24-kilowatt-hour battery pack while the car is switched on, essentially extending the car’s range. 

Enginer says its system also utilizes the Leaf’s stock level 2, 240-volt charging port, drawing an additional 5 amps of current from a compatible Level 2 charging station to simultaneously charge its own battery pack while the main Leaf pack charges. 

Complicated, involved install

Unless you’re a competent hobbyist who is happy working with high-voltage electronics -- and we’re assuming that the majority of Leaf owners aren’t -- the process of installing the Enginer battery system is lengthy and complicated. 

Not only does the installation require the removal of the rear seat, and direct access to high-voltage wiring, but it also requires splicing the Enginer wiring harness directly into the Leaf’s wiring harness, essentially making the modification permanent. 

Loss in load capacity

Enginer Supplemental Leaf Battery Pack

Enginer Supplemental Leaf Battery Pack

Enlarge Photo

As well as diminishing the physical space of the load bay, adding an additional battery pack has a negative effect on the load-carrying capabilities of the Leaf. 

In its stock form, the Leaf has a gross vehicle weight rating of 4,322 pounds, with a curb weight of 3,375 pounds. 

That leaves a total load capacity of 860 pounds, including passengers and cargo. 

By adding the smallest 4 kWh Enginer battery pack, the Leaf’s load capacity is reduced by 160 pounds. 

Add the largest, 12 kWh battery pack, and you diminish the Leaf’s load capacity by 360 pounds, or two full-size adults. 


While the Enginer system may sound like a great way to extend the range of a Nissan Leaf by between 20 and 40 claimed miles, the cost of the system doesn’t necessarily make sense. 

Although the 4 kWh system might seem a bargain at $3,495, you’ll have to pay extra for installation. For the high-end 12 kWh supplemental pack, you’ll find yourself handing over nearly $7,500.

2013 Leaf could give more

Although unconfirmed at this stage, several rumors about the 2013 Nissan Leaf hint that range could be improved to around 90 miles per charge instead of the 73 EPA-rated miles of the current model. 

For those wanting extra miles from their Leaf, waiting a few more months before committing to such an expensive modification to a relatively new car is a prudent move. 

Even if the 2013 Nissan Leaf doesn’t improve on the current range of the 2012 Leaf, it may be cheaper, easier, and less-risky for those wanting extra range to trade their Leaf in for a longer-range electric car, or a plug-in hybrid like the 2012 Prius Plug-in hybrid or 2012 Chevrolet Volt. 

Would you want to modify your Leaf in this way? 

Let us know your thoughts in the Comments below.


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Comments (20)
  1. Excellent report Nikki. It does seem like too high a cost for too little gain.

  2. Interesting option. I would want to know the heavy battery is secure and won't move around in case of an accident.

    Another reason to consider waiting for a 2013 Leaf (besides the rumored larger battery) is a 6.6 kW charger vs. the current 3.3 kW version.

  3. It seems like a silly thing to do now but...at some point the Leaf's battery will have degraded to the point it doesn't have the range you need any more and adding some extra capacity could be an efficient way to restore range again without having to throw out the main battery that still has a lot of life left in it. Good to see that the space for such an add on is there (sort of..). What's still needed is higher energy density batteries to avoid adding too much weight and volume. Maybe Tesla could branch out offering neat little 1KWH modules for this purpose. Should have twice the energy density of LiFePo. Shouldn't need the DC-DC converter either with so many cells on tap for series wiring.

  4. I have been waiting for someone to do this! now that it is out there more people will tackle the idea.. Hint to Nissan give me up to 140 miles and the Leaf will sell like hot cakes...

  5. Agreed, Nissan et al. need to be chasing that 150 mile mark aggressively if they want these cars to be successful.

  6. Ditto!

  7. It seems to be very expensive and took up too much cargo spaces. Also, the additional weight will degrade performance as well. The car is already heavy. With additional 360lbs, the acceleration will be even worse. Also, additional weight will reduce some of that range efficiency as well.

    I don't see any cooling/heating devices built in, how does it handle the harsh cold and hot climate?

  8. Won't this void any factory warranty? If your air conditioning or power steering goes out, can Nissan deny remedy? To own a non-warrantied 2012 Leaf for more money than an increased range 2013 model is a bit crazy. If I developed a retrofit kit for the Prius and was suddenly upstaged by the Toyota factory, I too would try and "pawn it off" on Leaf Owners. Maybe the Enginer battery pack will show up next on a bicycle to extend range.

  9. the best way to increase rang of a leaf would be to reduce the 3400 lbs if it was 2500 you would increase the range buy 1/3.

  10. the reason they won't make a 200 miles per charge car is it could become a free energy machine.

  11. And just how would you pull off such a miraculous weight reduction? Exotic carbon fiber would get you part way there but at what cost? Electric cars have re-gen capability, so weight is not as much of an issue as ICEs, so your range increase would be very little, no where near your claimed 1/3.

  12. Sounds like a good option for a narrow slice of the Leaf owner market. Those with commutes at or just longer then the current Leaf range would love/need it.

    For me, and sounds like most below, no thanks...still waiting for the longer range Leaf next year or another budget EV w/ range closer to 200 miles.

    10 comments below and no one picked up on one small mistake Nikki had in the article:
    "Add the largest, 12 kWh battery pack, and you diminish the Leaf’s load capacity by 360 pounds, or two full-size adults."
    Uh no Nikki...maybe 30 years ago. This decade, 360lbs is the avg weight of one out of every four American adults. Fat bastards many of us are...unfortunately it will probably get worse.

  13. hahah. Just couple days ago, I read a 12 yr old middle school kid was 290 lbs and was banned from playing PV Football and the mother had complained about it...

    When I was 12 yr old, I think I was around 110 lbs...

  14. OK, Nikki math (or maths as the Brits say) looks OK.

    "the average weight for men aged 20-74 years rose dramatically from 166.3 pounds in 1960 to 191 pounds in 2002, while the average weight for women the same age increased from 140.2 pounds in 1960 to 164.3 pounds in 2002."

    Of course that data is 10 years old... so...

  15. It seems that the car manufacturers never give people what they want which in this case is range. The car makers need to wake up and listen to the market. It is great that companies like Enginer etc are listening to the market and addressing what buyers want.

  16. My Leaf has too much range for my needs. I have charged to 80% on all but a few occassions. The few times I went to 100% was just to see how long of a round trip I could do if I had to which turns out is about 35 miles, mostly on the highway at 65mph. Would I pay less for less range? Probably not since I would eventually resell the car and a car with less range is hard to sell to the uninitiated.

    I cannot understand why anyone with a Leaf doing the average of 30 miles would charge during the daytime though. I simply don't get it.

  17. And by 35 miles I mean each way for a total of 70 highway miles on a full charge, more or less.

  18. I'm with you Jim. I have 10,600 miles on my Leaf and have yet to charge away from home. Knew the range when I bought it and wouldn't have if it wasn't sufficient for 90% of my needs. I have an old van so I can take the trash to the dump etc. Most households have an ICE car as a second vehicle.

  19. if you can charge for free, why not? but paying a lot for a charge is a different matter entirely.

  20. I'm excited to see this as a possible option - I have about 11,000 miles on my leaf - I use it for most everything - and often have to charge it for an hour or two during the day in order to get the 100 mile range out of it. I'm not sure I'm so big on adding something to the trunk - I wonder if there are additional battery modules that can be added directly to the main battery bank. I know Tesla puts something like 85 kilowatt hours into their cars - I wonder if the entire batter bank were switched out for a solid state battery instead if it would be possible to achieve this in the Leaf? I'll keep reading and searching -

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