[nordsieck]

Probably not.

1. Electric vehicles are a terrible fit for military operations

2. The actual HMMWV is a steaming pile of garbage. Not sure why the US Gov would want to buy an expensive version of the same thing

3. The HMMWV was recently replaced by the JLTV - it'll probably be at least 20 years before the next refresh cycle

[Gibbon1]

I have wondered about an electric tank. Some advantages. Doesn't require air. No thermal signature. Quiet potentially. Instant power. No diesel fuel to catch fire. No hydraulic system. Potentially redundant drive and actuators.

[playeren]

Electric motors still have a thermal signature, although obviously way smaller than a combustion engine + exhaust. Also, diesel doesn't really catch fire that easily (some tanks even proudly 'wear' extra fuel cans on their sides). Diesel is still very, very energy dense compared to batteries (for the time being), so for any campaigns away from established infrastructure, you'd rather be hauling diesel than batteries.

https://en.wikipedia.org/wiki/Stridsvagn_103#/media/File:Str...

https://en.wikipedia.org/wiki/Energy_density#/media/File:Ene...

[nullc]

> No thermal signature.

That's isn't how thermodynamics works.

It could have a reduced thermal signature but infrared cameras are so absurdly sensitive so it isn't obvious to me that a reduction would be a big advantage.

> Potentially redundant drive

Diesel-electric would have the same redundancy advantages: https://oshkoshdefense.com/engineering-solutions/propulse/

> No diesel fuel to catch fire.

Diesel is relatively hard to get to burn as liquid fuels go... lithium chemistry batteries aren't particularly known for being fire free.

[nordsieck]

Sure. That's all good stuff.

But fundamentally, EVs really only work well when vehicles can recharge on a grid. The Military wants to be able to operate away from the grid.

[TeMPOraL]

With all this talk US military has been doing about the changing theater of war in XXI century, about how it needs to refocus on effective operations in urban areas, I wonder: do they always assume that the power grid will be off? If not, then there may be some utility in a light and fast electric vehicle that parasites off enemy's power grid (and has solars or diesel aggregate as backup).

Also, did the military consider hybrid vehicles for similar role? They have the capacity to operate off-grid, and also switch to completely silent when tactically useful.

[nordsieck]

> do they always assume that the power grid will be off? ... Also, did the military consider hybrid vehicles for similar role?

I want to be up front - I'm far from privy to the military's decision making, which is byzantine and absurdist on a good day.

However, I think I can pretty safely say that the issue is not whether the military assumes that the grid will be off, but rather they don't assume that the grid will be on.

I think the closest they might get is a plug-in hybrid. However, that adds quite a bit of weight and complexity to a vehicle. I honestly don't know one way or the other how well that would work for armored vehicles, which are typically quite a bit heavier than you're probably used to thinking.

For example: homemade armor is typically 1/4" hardened steel plate welded to the outside of vehicles (thin skinned trucks, etc.) - about 2x the thickness of the Cybertruck's body. I'd assume that most purpose built armor kits are even heavier than that.

[villgax]

On 1, how couldn't silent operation be anything but a boon. Airdropping battery packs would appear to be safer than gas right?

[nordsieck]

> Airdropping battery packs would appear to be safer than gas right?

This is the most absurd statement I've read on HN in the past week. Just take 20 seconds and think about the logistics of a 60+ ton tank in the middle of nowhere doing a battery swap.

[salty_biscuits]

If (and it is a big if) electric power had an advantage, surely they would just have a support vehicle with a big generator that they could recharge from.

[nordsieck]

> If (and it is a big if) electric power had an advantage, surely they would just have a support vehicle with a big generator that they could recharge from.

On the actual power generation side, electric might have an advantage. But the range and recharging story is just too awkward to make sense. I'm not saying never: if battery power density jumped up 10x, they might be able to make it work. Just not right now.

1. Armored vehicles can have enormous gas tanks. The Abrams has a 500 gallon gas tank. If needed, it's pretty easy to double the size of the tank by strapping 10 5-gallon gas cans to the size of the vehicle. I just don't see how current battery technology could hope to compete with that.

2. The vehicle that refuels front line troops is the HEMTT. It carries 2500 gallons of petroleum and can fuel 2 vehicles at a time, maybe 5-10 times faster than a gas station.

That means that these vehicles can drive up to the front lines, fuel up vehicles and leave quickly so that they're less of a target and the front line vehicles can get back to doing what they need to do quickly.

In your generator scenario, you still need the fuel trucks, but there's an additional truck that has to sit there, charging vehicles for a long time.

I just don't see it working.

[goatinaboat]

Airdropping battery packs would appear to be safer than gas right?

Absolutely not! A lithium battery is fragile and highly flammable. Diesel is much safer to transport.