Replacement Battery for Stealth Bomber

Hey everyone. I have a 2011 Stealth Bomber, serial number 197, with the original 5200W motor, and my battery finally packed up. I'd be grateful for advice where I can purchase a replacement. I'm in the US and the dealers here ask US$ 2,000 for the Stealth OEM battery. I've seen some of you build your own, but that's beyond my capabilities, I fear. I have no qualms rebuilding anything mechanical, but electrical work is a mystery to me. The original battery is a 72V 18AH LiFePo4, and it looks like I need a BMS at least capable of 80A. I've seen some options on AliExpress in the $700 range, but they're either the right dimensions with a 40A BMS, or those with an 80A BMS or above are too large to fit in my bike. Any recommendations where I might find something that fits (36cm/15cm/12cm) with at least 20AH for under $1,000?

Lastly, just as an aside - all the options I see including those from Stealth seem to be in the 12kg weight range. I've been replacing my motorcycle batteries with lithium ion batteries from Shorai, and those are featherweight by comparison. Is there a similar option available for eBikes? That I'd definitely be willing to pay more for

Hey everyone. I have a 2011 Stealth Bomber, serial number 197, with the original 5200W motor, and my battery finally packed up. I'd be grateful for advice where I can purchase a replacement. I'm in the US and the dealers here ask US$ 2,000 for the Stealth OEM battery. I've seen some of you build your own, but that's beyond my capabilities, I fear. I have no qualms rebuilding anything mechanical, but electrical work is a mystery to me. The original battery is a 72V 18AH LiFePo4, and it looks like I need a BMS at least capable of 80A. I've seen some options on AliExpress in the $700 range, but they're either the right dimensions with a 40A BMS, or those with an 80A BMS or above are too large to fit in my bike. Any recommendations where I might find something that fits (36cm/15cm/12cm) with at least 20AH for under $1,000?

Lastly, just as an aside - all the options I see including those from Stealth seem to be in the 12kg weight range. I've been replacing my motorcycle batteries with lithium ion batteries from Shorai, and those are featherweight by comparison. Is there a similar option available for eBikes? That I'd definitely be willing to pay more for

crb8783 said:

The original battery is a 72V 18AH LiFePo4, and it looks like I need a BMS at least capable of 80A.

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What is the continous and peak current rating of your controller? That's what your battery must be able to handle.

Next, what range do you need from the bike? Do you typically use the whole capacity of the pack? (or at least, did you, when it was newer?) Or do you need *more* range than it gave you? Or less?

If you don't need as much range, you can get a smaller pack, as long as it can handle the current demand of the controller.

If you need more range, then you need a bigger pack.

I've seen some options on AliExpress in the $700 range, but they're either the right dimensions with a 40A BMS, or those with an 80A BMS or above are too large to fit in my bike.

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That generally means they're using crappy cells that can't handle the higher C-rate (current), so they have to use more cells to make up for that. Something to consider is that cheaper prices typically mean cheaper, less capable, lower quality products, especially with batteries.

The battery is the heart of your bike, and if it can't handle the things you need it to do, then the bike won't perform like you need it to, and if it's pushed harder than it can handle, it also won't last as long as otherwise.



Lastly, just as an aside - all the options I see including those from Stealth seem to be in the 12kg weight range. I've been replacing my motorcycle batteries with lithium ion batteries from Shorai, and those are featherweight by comparison. Is there a similar option available for eBikes?
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You've already got one in the Stealth.

How many Wh is the MC starter battery? What chemistry is it? (most of them seem to be LiFePO4).

If it's the same chemistry, then to be much lighter it would have to be much less capacity. (it is already only 1/6th the voltage). If it's a different chemistry, some of the lithium types are much lighter than LiFePO4.

The battery you already have is 72v * 18Ah = 1296Wh.

FWIW, most likely the newer batteries from Stealth are lighter than what you have now, if they've changed chemistries from LiFePO4 to something else. Even if they haven't, they're probably still either lighter or have more capacity (or capability), as battery tech has improved a little since yours was made.

No junk batteries as the word Tesla like cells means nothing in sales propaganda But 2,000 usd my not be to much what are the specs ? As 1,000 is to cheap for a zero battery. The battery is the heart of the machine.

Can you post some pics of your bike and tell about some of your Adventures riding your bike

crb8783 said:

72V
at least 20AH for under $1,000?

Lastly, just as an aside - all the options I see including those from Stealth seem to be in the 12kg weight range. I've been replacing my motorcycle batteries with lithium ion batteries from Shorai, and those are featherweight by comparison. Is there a similar option available for eBikes? That I'd definitely be willing to pay more for

Click to expand...

Base on the motorcycle batteries I see, that are 13V 6Ah, you need five in series and 4 parallel groups to meet your requirement. Assuming 1.35lb each, and 20 batteries, that's 32.4lb, or 14.7kg. Seems like it's in the same ballpark.
https://www.amazon.com/Antigravity-Batteries-Lithium-Motorcycle-Battery/dp/B07NPZRM38/ref=asc_df_B07NPZRM38/?tag=hyprod-20&linkCode=df0&hvadid=319850198764&hvpos=&hvnetw=g&hvrand=17022197537066978219&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9032087&hvtargid=pla-698078613484&psc=1