A few minutes with Philippe Bouchard of EOS Energy Storage

Well, today I had a great conversation with Mr. Philippe Bouchard of EOS Energy Storage.  They make a new Zinc-Air battery.  And it is a technology that I have been very excited about.  But my excitement has been tempered a bit.

Today I got to confirm a few things.  First off is their make up.  The US has one of the largest amounts of Zinc of anywhere in the world.  So economic advantage and national security, check.  There are no heavy metals, and the electrolyte is almost a saline solution.  So, your 2-yr old won’t die if some how they managed to take your car apart and started gnawing on it.  They also won’t catch on fire if over-charged, over-discharged, crashed, or punctured.  So they are safe, check.  Next, they are designed to last 10,000 cycles.  Long lasting check.  They cost $160/kWh, which is about 1/3 of what an A123 will cost you.  They are affordable, check.  They are capable of 620Wh/L vesrus Lithiums 230Wh/L.  So over 2.5 times the energy density, check.  The BMS is way simpler than Lithium batteries require to keep from bursting into flames.  Simpler and cheaper BMS, check.

So they have 2.5 times the power density, cost 1/3 as much, will not burst into flames, will not harm the environment or yourself in anyway, and strengthens the US economy!  Is this a miracle battery!?  Unfortunately no.  Unlike the Lithium batteries you see in any of the bikes in the race series which have C rates of 15C, this battery has a discharge rate of 1/6C, and is only available in grid applications.  Yeah I know, my bubble bursted too.  Although, they are in contact with auto manufacturers trying to find a partner to help them develop the auto battery.  Trust me I gave him a pretty good de-breifing about elmoto racing.  Not as bad, but not that helpful is that the charge rate is 1/6C as well.  This means that the battery takes 6 hours to completely charge or discharge at full throttle.  Although, Mr. Bouchard did say that they are working on some surge protectors that might allow up to 1/3C.  That’s basically like giving a turtle Red Bull.  Clearly this has little to no racing application.  To try to put in terms of motor power, start with the amount of power you want your motor to have.  Lets use Brammo’s new Empulse, and it’s 40kW motor, for example.  A 40kW motor at full power could drain a 40kWh pack in 1 hour.  That is 1C. So the Empulse’s 40kWh motor could potentially suck it’s 9.31kWh pack in a touch under 14 minutes (do NOT try this at home), or 4.3C.  So if you had a 9.31kWh EOS pack in the bike the biggest motor you could run is a 1.6kW (or 2hp).  Yep, that’s pretty weak.  But, what if we replaced the Empulse’s pack with a physically identically sized pack?  Well, we end up with a 25kWh pack, that weighs a bit more than the 9.31kWh lithium pack.  That takes the ranges from 121/77/56 miles to 325/206/150 miles!  But to keep the stock motor we would need a 1.6C rate, which is 9 times the discharge rate that the technology has now.  Basically, the biggest motor you could run is 4.1kW (or 5.6hp).  So depressing.  However, they are also looking at pairing their Zinc-Air batteries with their Lead-Acid concept or someone else’s capacitors basically allowing the Zinc batteries to constantly charging the L/A batts or capacitors while they release the bursts of power that an EV needs.  But even then.  The TT Zero bikes are emptying their packs in 20 minutes.  That’s 3C constant.  Not to mention that even though it gets us a Lightning with 37.7kWh, albeit a bit heavier, but it’s still not the 55-60kWh I think elmotos need to compete with MotoGP bikes, at the same weight (170lbs lighter than it is now).

It’s such a great product, but just not for us elmoto guys.  When I build a street bike in my head I always think of my VFR first.  Basically a 500lbs bike with a 75kWh (or 100hp) motor.  So, a 30kWh pack would need a 2.5C rate.  But then I think a 150kW (or 200hp) “liter” bike might need a a smaller pack for less weight, so a 25kWh would need a 6C rate.  These types of bikes will stay in the realm of lithium batteries.  There might be some hope for touring bikes.  Can you imagine an electric Goldwing, costing way less than a GSX-R?  We’ll just have to wait for lithium-air. [sigh]

6 thoughts on “A few minutes with Philippe Bouchard of EOS Energy Storage

  1. “They are capable of 620Wh/L vesrus Lithiums 230Wh/L.”

    Do you mean Wh/kg? EIG C020 used by Zero is 362Wh/L.

    Heterogenous batteries are a good idea .. hard to make work well together, and they’re always a tradeoff WRT how much high power vs high energy battery you use. Here’s a (somewhat dated) EV conversion that uses lithium for bulk energy storage and capacitors for discharge / KE recovery.

    http://www.metricmind.com/ac_honda/main.htm

    ***

    Best way to address the energy vs power tradeoff is add positions for tank / tail / saddlebag attachment, allow consumer to buy / rent batteries for longer trips. Too much of a niche market now, in the future? Well, we need EV sales : )

    Assume battery module is 10kg. If 620 Wh/kg, that’s 6.2 kWh, 1kW charge/discharge.

    A long low-speed trip on my Zero is 83 miles @ 40-45 mph, 2 hours, 4 kW discharge.

    Add 1 module and you reduce draw from main pack by 25%, extend range by 33% (main pack fully discharged, ZA @ 60%).
    Add 2 modules and you reduce draw from main pack by 50%, extend range by 100% (main pack fully discharged, ZA @ 33%).
    Add 3 modules and you reduce draw from the main pack by 75%, extend range by 230% (both packs fully discharged).

    A single module could keep me topped up at work where I cannot charge.

    Always tradeoffs. These batteries would be perfect for home solar storage, too. 4 kW PV @ $8-10k, 12 kWh ZA battery storage @ $2k, inverters, racks, misc control bits @ $2k. So much cheaper than deep-discharge LA over time.

    1. Nope, they didn’t have Wh/kg numbers for me. They are working on grid solutions at the moment, so their numbers are volumetric. I’ll have to see if I can get a Wh/kg rating. I think it will be around 600W/kg though.

      1. Ah.. well, Wh/kg should be pretty good. Wh/L is certainly important for motorcycles as well, but much less of a criteria in a well-designed EV car. (Look at Tesla Model S, even the 85 kWh battery sheet is about six inches thick w/ packaging).

        1/6C is very unfortunate. 1/3C or 1/2C with good density and pricing would be phenomenal when paired with high-power lithium booster. I’m sure they’re working that side.

      2. They are working on 1/3C (both charge and discharge) with a surge limiter. They may have to modify the chemistry. I thin they are trying to avoid lithium. Their boosters will be a slick lead acid they are working on, or capacitors. But, they may end up at Lithium.

  2. And they’re almost useless for highway applications.

    The three module setup would increase range by 60% @ 60 mph, by 23% @ 70 mph.

    Current 7.9 kWh bike has roughly 80 mile range @ 40 mph, 60 mile @ 60 mph, 43 mile @ 70 mph.

    Add 3 modules, and now you have 260 mile range @ 40 mph, 96 mile @ 60 mph, 53 mile @ 70 mph.

    Consider instead a fairing which adds 20 lbs, reduces drag by 40% (optimistic).

    Faired bike would have roughly 100 mile range @ 40 mph, 80 mile @ 60 mph, 65 mile @ 70 mph.

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