How long are we expecting the Stark battery to last (long term)

[UKLee]

Our surron and freeride E have been in use for 3 and 2 years with no big drop off in how long each full charge lasts, What are people expecting from the stark and what is the manufactures warranty going to cover? At over £6000 a go I do not want to be buying many of those over the bikes lifetime or I might as well run 4 stroke MX bikes.

Did anyone run an Alta long enough to see a drop off in the battery?

Might it be possible to get the cells changed in the stark battery when the time does come?

 

[Beagle]

Very curious about this as well.
Experience will tell but from what we know here is a small "theoretical" calculation.

I think Stark 6.5kWh battery pack uses 400 x 21700 Molicel P45B batteries.



Say you need to get a new battery after 500 cycles when you may have lost about 20% range (that means 5-10 min less for MX, maybe 20 min less for enduro).

Taking an average MX range of 45 min, 500 cycles is 375 h run time.

Now $7000 spare battery is a lot, and not a cost spread over time. But to put things into perspective, battery cost divided by 375 h is $19/h. Add electricity cost and gear oil change every 40 h, you're looking at $20/h run time.

Now if you're more a woods, enduro or trail rider the range could be doubled (1h30) so it becomes more like 750 h for a battery replacement, so divide that hour cost by 2 ($10/h).

See how that compares with your typical ICE maintenance cost for 375 h. Excluding tires, chain, brakes, suspensions which would not be so different.

Don't know how many riders will keep the bike for so long though. And obviously curious to see how the battery holds in real life compared to the spec sheet.

How many hours did you log on your Surron and Freeride in 2-3 years?

 

[bayodome]

By the time the batteries need replacement, cells will be cheaper and more efficient. And if Stark continues on their path of innovation, they will likely have a solution for you, as will numerous aftermarket companies.

 

[happyinmotion]

Battery degradation depends very much on how hard the cells are pushed and specifically on the minimum Voltage under load and the maximum under charge.

My Sur-Ron with a stock battery has seen 250 cycles and 5,000 km over four years. It's lost at least 20% capacity. I've not been that hard on it but the minimum Voltage that the BMS allows seems pretty low, hence the battery gets damaged.

We know Stark have set very cautious limits on battery Voltage. Their range upgrade relaxes those limits. There's a trade to be made between usable capacity and battery life. Clearly Stark think they have enough data about how the bikes are being used to risk faster degradation to give more range.

 

[UKLee]

Very curious about this as well.
Experience will tell but from what we know here is a small "theoretical" calculation.

I think Stark 6.5kWh battery pack uses 400 x 21700 Molicel P45B batteries.

View attachment 10976

Say you need to get a new battery after 500 cycles when you may have lost about 20% range (that means 5-10 min less for MX, maybe 20 min less for enduro).

Taking an average MX range of 45 min, 500 cycles is 375 h run time.

Now $7000 spare battery is a lot, and not a cost spread over time. But to put things into perspective, battery cost divided by 375 h is $19/h. Add electricity cost and gear oil change every 40 h, you're looking at $20/h run time.

Now if you're more a woods, enduro or trail rider the range could be doubled (1h30) so it becomes more like 750 h for a battery replacement, so divide that hour cost by 2 ($10/h).

See how that compares with your typical ICE maintenance cost for 375 h. Excluding tires, chain, brakes, suspensions which would not be so different.

Don't know how many riders will keep the bike for so long though. And obviously curious to see how the battery holds in real life compared to the spec sheet.

How many hours did you log on your Surron and Freeride in 2-3 years?

Good work thanks for that, not sure what hours the surron and freeride have done and we have stored the batterys indoors over winter so not possible to check right now.

 

[UKLee]

By the time the batteries need replacement, cells will be cheaper and more efficient. And if Stark continues on their path of innovation, they will likely have a solution for you, as will numerous aftermarket companies.

Much as the stark marketing department tries to come across as enthusiasts doing us a massive favour building us these bikes I am sure that is not the case, It is a Business and there to make money, as much as possible.
They will make a lot more money on the sale of parts than they do on the bikes with most bikes it would cost about 5 times the cost of a new bike to build one from spare parts and the battery is the most expensive part so do not think for one minute they want it to last much past the warranty unless forced to by the aftermarket.

I also think there refusal to make the bike with a hot swap battery was to help shorted the battery life because what is worse for a battery than either using it hard on a mx track or putting it on fast charge, and at a mx race or practice you will be doing one or the other all day building up the heat in the battery as the day goes on.
It would be much better to have 2 or 3 slightly smaller batterys so less weight that are hot swap and will last the day then recharge them at home when they have cooled down and on a slow charge. Stark have proved this by running there bikes in the UK arenacross with less cells in them to reduce the weight but still enough power to last the short races then either recharging the battery or changing it for another reduced capacity one for the next heat/race later that day whilst retaining the standard look of the bike.

 

[UKLee]

Battery degradation depends very much on how hard the cells are pushed and specifically on the minimum Voltage under load and the maximum under charge.

My Sur-Ron with a stock battery has seen 250 cycles and 5,000 km over four years. It's lost at least 20% capacity. I've not been that hard on it but the minimum Voltage that the BMS allows seems pretty low, hence the battery gets damaged.

We know Stark have set very cautious limits on battery Voltage. Their range upgrade relaxes those limits. There's a trade to be made between usable capacity and battery life. Clearly Stark think they have enough data about how the bikes are being used to risk faster degradation to give more range.

We have always tried to do what we can to give the batterys on our surron and freeride an easy time like not running them flat and not putting the freeride on fast charge (no option with the surron) and even bringing the batterys indoors over winter which is not practical with the stark so it sits in the garage with a blanket wrapped around the battery area the best I can.

We have only had the stark out twice due to the very bad weather and I think it is an due an update or 2 by now but it makes me wonder do we want the update to increase the battery range? well yes we do want the extra range but at what cost in long term battery life, Have stark looked at the figures and seen the batterys are going to last longer than they would like so changed things to give the battery a harder time so they can sell more of those very expensive big profit batterys?

 

[Andreas]

My Stark is also in the basement right now, without 4G.

I don't want to update it either. Let's see if that's possible.

 

[Matt]

Much as the stark marketing department tries to come across as enthusiasts doing us a massive favour building us these bikes I am sure that is not the case, It is a Business and there to make money, as much as possible.
They will make a lot more money on the sale of parts than they do on the bikes with most bikes it would cost about 5 times the cost of a new bike to build one from spare parts and the battery is the most expensive part so do not think for one minute they want it to last much past the warranty unless forced to by the aftermarket.

I also think there refusal to make the bike with a hot swap battery was to help shorted the battery life because what is worse for a battery than either using it hard on a mx track or putting it on fast charge, and at a mx race or practice you will be doing one or the other all day building up the heat in the battery as the day goes on.
It would be much better to have 2 or 3 slightly smaller batterys so less weight that are hot swap and will last the day then recharge them at home when they have cooled down and on a slow charge. Stark have proved this by running there bikes in the UK arenacross with less cells in them to reduce the weight but still enough power to last the short races then either recharging the battery or changing it for another reduced capacity one for the next heat/race later that day whilst retaining the standard look of the bike.

I doubt that their choice of battery size was influenced by intentions of it wearing out sooner. From my perspective they are trying to be the Tesla of the MX world. To do that you need to demonstrate superior performance at the highest levels. Having a factory 450 rider run a full outdoor moto and do well proves that and in order to do that a decent capacity is needed.

For the every day rider running a full day of motos will require X battery capacity. X may be smaller if you have a lighter bike but my guess is not a ton. So even if you have a bike with a smaller battery and you bring extras to swap, at the end of the day you still need X capacity consumed at some rate. A hypothetical example may be for a full day of moto I would need 12-15 kWh of energy. Maybe a lighter battery/bike would get me through the day with 12 and a heavier would need 15 in either case I need to charge unless I bring that capacity in batteries which in either case would be very expensive.I think the real appeal of smaller batteries is having one charge, while you ride on another, minimizing down time.
Additionally the lighter weight from a performance perspective would be nice. I think this would probably be even harder on the batteries unless you had a lot of them which again would be very expensive.

Even at a 20% reduction in capacity due to degradation, for the average motocross rider doing 15 minute motos, this probably won't affect them much. I expect peoples bikes will last quite a long while if it's anything like the Altas.

From a start up perspective I imagine it's easier to commonize on a single design, so going after top tier performance to drive sales and keeping the design simple and unified would point to one larger battery that can serve the target market comfortably and stand out in a professional sense.

Just my opinion.

 

[F451]

I doubt that their choice of battery size was influenced by intentions of it wearing out sooner. From my perspective they are trying to be the Tesla of the MX world. To do that you need to demonstrate superior performance at the highest levels. Having a factory 450 rider run a full outdoor moto and do well proves that and in order to do that a decent capacity is needed.

For the every day rider running a full day of motos will require X battery capacity. X may be smaller if you have a lighter bike but my guess is not a ton. So even if you have a bike with a smaller battery and you bring extras to swap, at the end of the day you still need X capacity consumed at some rate. A hypothetical example may be for a full day of moto I would need 12-15 kWh of energy. Maybe a lighter battery/bike would get me through the day with 12 and a heavier would need 15 in either case I need to charge unless I bring that capacity in batteries which in either case would be very expensive.I think the real appeal of smaller batteries is having one charge, while you ride on another, minimizing down time
Additionally the lighter weight from a performance perspective would be nice. I think this would probably be even harder on the batteries unless you had a lot of them which again would be very expensive.

Even at a 20% reduction in capacity due to degradation, for the average motocross rider doing 15 minute motos, this probably won't affect them much. I expect peoples bikes will last quite a long while if it's anything like the Atlas.

From a start up perspective I imagine it's easier to commonize on a single design, so going after top tier performance to drive sales and keeping the design simple and unified would point to one larger battery that can serve the target market comfortably and stand out in a professional sense.

Just my opinion.

Agree completely.

If you look on this forum and use the Alta experience as a reference, I think the Varg owners will do just fine with their batteries long term and any battery degradation will take years and won't be a big negative for the majority of the owners. Battery degradation is a real thing, but I don't read a lot of complaining about it with the Altas, and don't expect to hear a lot about it from Varg owners. It was never an issue with my '18 MXR.

We will see, hopefully it works out fine.

 

[Theo]

I'm not sure either that a swapppable battery would be a wise choice for the Varg.
Let's say that the battery indeed has those 400 cells arranged in four series of 100 each a lot of people talk about: considering the datasheet in the post #2 and considering the rumors about the tactic implemented at the arenacross race they won in the UK, they could have used only 3 series of 100 each, saving 70 g • 100 = 7 kg and having 4.86 kwh instead of 6.48. They could have then made that lighter battery swappable.
Now even like that the rest of the cells would still weigh 21 kg + the rest of the battery: could the total be maybe 25 kg? It wouldn't be so easy to move. We woud also need a way to fasten it safely, quckly and reliably even in wet/muddy conditions and probably such a design would need a bigger mass than a fixed battery design, reducing the weight advantage.
Besides, the extra battery would probably cost a lot anyways, like Matt said.
So I'd say that the cons would out balance the pros and that therefore the choice of a fixed battery is presumably mainly motivated by the intention to satisfy the customer.

 

[Beagle]

Good point, for me swappable batteries make sense for lighter and less powerful bikes, so you don't have to lug around a hefty and very expensive spare.

Or maybe just for (pro) enduro riders, like when Taddy B completed his first 3 h race.

 

[Foss]

The only thing worth mentioning which from what I have observed so far is I have not seen any mention of a ‘failed’ battery here in the community, and/or out in the wild on the internet.

And if there is, it could have been quickly resolved by stark future and replaced no questions asked to maintain their image.

As far a battery lifecycles I would say we are bound by the materials used in most modernized batteries. So degeneration would be seen in time like any other battery.

 

[Dain_SSE]

My biggest concern is the small parallel group of cells, 4P. This means a single weak cell, 1 weld connection broken out of 800 in a 400 cell pack - capacity is dropped to 75% if the BMS even allows it to continue to run on a group of 3 that will be overworked 33%. I also haven't seen or heard of failed packs/reduced capacity packs meaning they have their proccesses dialed and robust quality checks in place - or are covering it up!

 

[Foss]

With a start up company like Stark Future I would not be too concerned with them resisting on any request of a faulty battery. I have experienced exceptional service (lacking communication) with stark going above and beyond replacing parts. FWIW

Seeing Stark is very innovative, I also believe Wass will explorer alternative inexpensive battery tech like carbon batteries.

 

[Beagle]

I could be wrong but I think that's the first official confirmation that Stark is using P45B cells.

https://www.molicel.com/announcement/electrifying-milestone-for-molicel-stark-future-makes-history-as-first-electric-vehicle-manufacturer-winning-over-combustion-in-motocross-track-racing-championship/

Now that P50B are around the corner, can't be that long before they test them. As the name suggests, they are 5 Ah cells with 11% more volumetric density. Switching the 400 cells pack to P50B, capacity would increase from 6.5 kWh to 7.2 kWh (with an extra 800 g) or just 7.0 kWh while keeping the exact same weight.

2022 prototype was using P42B for 6.0 kWh capacity,
2023 production bike used P45B to get to 6.5 kWh,
with P50B that could soon be increased to 7.2 kWh,

that would be some serious range increase in a couple of years.

 

[Swank171]

Hopefully our bikes are future proof and the battery will be a swap scenario….