5thGenRams Forums

Register a free account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!

2025 brochure

Jamesalan98

Active Member
Joined
Dec 15, 2019
Messages
44
Reaction score
40
Even Tradesman? Sounds like what Toyota has done on the new Tacoma. Safety package is standard across the board. Of course, we have to remember that "standard" doesn't mean you save money. They just lump it into the MSRP. But still, if the base models can now GET the adaptive cruise, that's awesome.
it really shouldn’t be surprising to see safety features on base models of trucks since this is what they do in most crossovers. Even the base models on many crossovers come with many standard features and now the trucks are getting them. It makes sense to do it because if differentiates the new trucks to the old ones, which justifies buying a new one. This does add to the price but not that much. The price increases on these Rams already happened when they didn’t add anything to them and then they wonder why people are not buying them.
 

jimothy

5thGenRams Supporter
Site Supporter
Joined
Dec 18, 2020
Messages
1,253
Reaction score
2,527
Location
Atlanta, GA metro
Is there a real downside to having 660 hp? If you put a 400 hp motor on it, you're just collecting whatever savings it takes to build the more powerful motor, the battery probably wouldn't change but instead give you more theoretical range. It's not like a gas engine where when you run 600 hp you trash the savings from a smaller engine. With electrical motors, if you're not using 600 hp it's not costing you anything (well, I'm sure there are very very minor efficiencies by running a motor capped at 400 ish hp, but it wouldn't be worth the tradeoff IMHO). And we absolutely need this range for towing, even then I suspect it will have less range vs my current truck but I can live with that (just carry a gerry can or two).

I like the specs on the Ram charger. It should be great towing machine which is how I look at all trucks. It's more of a 2500 at this point, 8 lug wheels, lots of power, lots of range.

I'd buy this much faster than the SO SST (depending on cost).
Good question. I'll go through some math to explain the downsides. Rather, I'll demonstrate how less EV range can translate to less electric power (in kW or HP).

But first, let me clear up that I'm not saying there shouldn't be a 660 HP RamCharger. I'm saying, I hope there will also be a less expensive model with lower power, achieved by a smaller battery and possibly smaller electric motors. It could be that by making it lighter, its total range (EV + gas) is changed little. Perhaps with less weight and less powerful motors, total range might even go up. I don't tow, but my guess is total range matters to you more than electric range.

If you want to skip the math, here's a summary: Reducing the battery size by X% will also reduce the maximum electric power by the same percentage. Because the gas generator power remains the same, the total reduction in power will be less than X%.

Electric power is volts * current. Maximum current of a battery is related to the size of the battery. With most lithium batteries, the maximum recommended, continuous current is 1C, meaning one times the capacity of the battery in amp-hours (Ah). A 100 Ah battery typically has a 100 A max discharge rate, 200 Ah battery has a 200 A max discharge rate, etc. Discharging (and charging) lower than 1C will extend the life of the battery, often significantly. Likewise, higher discharge and charge current can shorten the life of the battery.

Ram specs the RamCharge as having a 92kWh battery. Assuming 400V, that means 230 Ah, thus 230 A is the maximum continuous current assuming 1C.

Regardless of voltage, at 1C, the power in kW is equal to the capacity in kWh (just multiply max current, 230 A, by 400V, and you're at 92kW). Thats equal to about 123 HP, well below 660 HP.

The difference can be made up in part via the gas generator, which is rated at 130kW or 174 HP. That brings us to 297 HP, so we're still 363 HP short. (Let's just assume, for simplicity, that the power from the batteries and generator add perfectly with no losses; I'm also neglecting other losses to keep calculations simple).

That deficit will have to come from discharging the battery at greater than 1C, which can be done for short bursts. Since we're not going to be full throttle for an entire drive, this is acceptable, though it does have some impact on battery life (i.e., if you constantly floor it, your batteries won't last as long as with a lighter foot).

So we're going to need 486 HP, or 362 kW, from the batteries for the full 660 HP. That's about 900 A at 400V, or 3.9C for a 230Ah battery.

Let's say that, because of weigh savings, a 30% reduction in range allows for a 40% smaller battery. This means, instead of a 92kWh/230 Ah battery, this lower-spec RamCharger comes with a 55 kWh/138 Ah battery.

Assuming the same 3.9C discharge rate, the lower range battery would be able to provide only 217 kW (3.93 * 138A * 400V / 1000), or 291 HP (40% less than the actual RamCharger). With the same 130 kW generator, that's a total of 347 kW or 465 HP, a bit over my target 400 HP, but I'll take it! The total decrease in HP is around 30%, not 40%, because the power from the generator remains unchanged.

Maybe my 30% reduction in range, 40% reduction in battery size is unrealistic; maybe a 33% smaller battery is more realistic. But the general point would still stand: A reduction in battery capacity implies a proportional reduction in electric power, unless you increase the battery discharge rate which negatively impacts battery life.

If the reduced EV range RamCharger could also use smaller and less expensive electric motors, then the cost and weight would be further reduced. But Rams sales and marketing departments may have zero interest in my idea.

P.S. To produce the same power as the 92kWh battery, the 55 kWh battery would need to discharge at 6.5 C, or 67% higher. If that's even possible, it would surely be bad for battery life.
 
Last edited:

silver billet

Spends too much time on here
Joined
Apr 18, 2019
Messages
2,450
Reaction score
2,372
Good question. I'll go through some math to explain the downsides. Rather, I'll demonstrate how less EV range can translate to less electric power (in kW or HP).

But first, let me clear up that I'm not saying there shouldn't be a 660 HP RamCharger. I'm saying, I hope there will also be a less expensive model with lower power, achieved by a smaller battery and possibly smaller electric motors. It could be that by making it lighter, its total range (EV + gas) is changed little. Perhaps with less weight and less powerful motors, total range might even go up. I don't tow, but my guess is total range matters to you more than electric range.

If you want to skip the math, here's a summary: Reducing the battery size by X% will also reduce the maximum electric power by the same percentage. Because the gas generator power remains the same, the total reduction in power will be less than X%.

Electric power is volts * current. Maximum current of a battery is related to the size of the battery. With most lithium batteries, the maximum recommended, continuous current is 1C, meaning one times the capacity of the battery in amp-hours (Ah). A 100 Ah battery typically has a 100 A max discharge rate, 200 Ah battery has a 200 A max discharge rate, etc. Discharging (and charging) lower than 1C will extend the life of the battery, often significantly. Likewise, higher discharge and charge current can shorten the life of the battery.

Ram specs the RamCharge as having a 92kWh battery. Assuming 400V, that means 230 Ah, thus 230 A is the maximum continuous current assuming 1C.

Regardless of voltage, at 1C, the power in kW is equal to the capacity in kWh (just multiply max current, 230 A, by 400V, and you're at 92kW). Thats equal to about 123 HP, well below 660 HP.

The difference can be made up in part via the gas generator, which is rated at 130kW or 174 HP. That brings us to 297 HP, so we're still 363 HP short. (Let's just assume, for simplicity, that the power from the batteries and generator add perfectly with no losses; I'm also neglecting other losses to keep calculations simple).

That deficit will have to come from discharging the battery at greater than 1C, which can be done for short bursts. Since we're not going to be full throttle for an entire drive, this is acceptable, though it does have some impact on battery life (i.e., if you constantly floor it, your batteries won't last as long as with a lighter foot).

So we're going to need 486 HP, or 362 kW, from the batteries for the full 660 HP. That's about 900 A at 400V, or 3.9C for a 230Ah battery.

Let's say that, because of weigh savings, a 30% reduction in range allows for a 40% smaller battery. This means, instead of a 92kWh/230 Ah battery, this lower-spec RamCharger comes with a 55 kWh/138 Ah battery.

Assuming the same 3.9C discharge rate, the lower range battery would be able to provide only 217 kW (3.93 * 138A * 400V / 1000), or 291 HP (40% less than the actual RamCharger). With the same 130 kW generator, that's a total of 347 kW or 465 HP, a bit over my target 400 HP, but I'll take it! The total decrease in HP is around 30%, not 40%, because the power from the generator remains unchanged.

Maybe my 30% reduction in range, 40% reduction battery size is unrealistic; maybe a 33% smaller battery is more realistic. But the general point would still stand: A reduction in battery capacity implies a proportional reduction in electric power, unless you increase the battery discharge rate which negatively impacts battery life.

If the reduced EV range RamCharger could also use smaller and less expensive electric motors, then the cost and weight would be further reduced. But Rams sales and marketing departments may have zero interest in my idea.

P.S. To produce the same power as the 92kWh battery, the 55 kWh battery would need to discharge at 6.5 C, or 67% higher. If that's even possible, it would surely be bad for battery life.)

I'll give you an E for Effort! :) And I'm not an electrician so I'll have to take your word for it.
 

Users who are viewing this thread

Site Vendors

https://www.jasonlewisautomotive.com/
Top