Your thoughts and suggestions for this

[Nvreloader]

I want a backup battery to go with the 2 OEM battery's for my Wart Hog MD 750 bike,
as the next series of rides are going to be at the extreme edge of the OEM battery range,
70 miles one way, my OEM batteries are 48v-30A controller, 21700 battery has 39 cells/13 in series,
3 in parallel, 15ah/720wh x 2.

I am looking at this 52v 21700 battery, last one at the bottom of the page, see info here,

52V 48V 36V 8Ah 10Ah 12Ah 15Ah 20Ah Ebike Battery Electric Bike Lithium Battery | eBay

��36V 8AH ebike Battery Electric Bike Scooter Lithium Battery with Waterproof Case. 【Light and fun battery】The battery is light, especially suitable for disguising the ebike into a bike, making friends feel that the angel is riding without the help of electricity.

www.ebay.com

My concern is the BMS: 40A/52C and my bike is 30A/48V, I don't understand all these spec's.
This is the smallest triangle case I can find to fit my bike with 21700 cells, that I have found so far.

Your thoughts...........
Tia,
Don

 

[tomjasz]

Run don’t walk. Unless you’re cash strapped.

“Hailong” is a case maker not a battery. No idea what the cells are and likely cheap generic. Those sellers greatly exaggerate specifications. You ride in rough conditions. Likely to be a glued cell pack with generic no name cells. Use caution.

Ebike Triangle Battery | EM3ev

em3ev.com

 

[PedalUma]

Don, @tomjasz knows. Cell quality makes all the difference. "You can't make good wine with bad grapes." I am in the wine country and now is harvest.

 

[6zfshdb]

I don't know specifically about the controller on the Wart Hog but I get an overvolt error on several 48V controllers I've tried to use with a 52V battery. Charging to 80% or so might solve the problem or you can stick with a 48V battery.

I agree with @tomjasz above. The cells in the battery you're looking at are questionable. Spending a few $$ more on a quality battery would be a safer bet.

 

[Nvreloader]

Thanks Guys,
Question for you all,
Are there different types of 21700 cells?
This is part of the info posted on these 21700 cells > I thought that Panasonic was a good brand of cells? I am confused............

Description
Normal Voltage: 52V
Rated Capacity:20AH
Battery cell: Panasonic 21700 Class A battery
BMS: 40A
Charge voltage:2-5A
Discharge cut off voltage:58.8V
Configuration: 14S4P （4P*5000mAh=20000mAh=20Ah）
Max Constant Discharge Current: 40A( BMS)
Apply for: 100-1600W Motor
Charger : 58.8V 4A
Battery Cell: 3.7V 5000mAH Cell

 

[6zfshdb]

Thanks Guys,
Question for you all,
Are there different types of 21700 cells?
This is part of the info posted on these 21700 cells > I thought that Panasonic was a good brand of cells? I am confused............

Description
Normal Voltage: 52V
Rated Capacity:20AH
Battery cell: Panasonic 21700 Class A battery
BMS: 40A
Charge voltage:2-5A
Discharge cut off voltage:58.8V
Configuration: 14S4P （4P*5000mAh=20000mAh=20Ah）
Max Constant Discharge Current: 40A( BMS)
Apply for: 100-1600W Motor
Charger : 58.8V 4A
Battery Cell: 3.7V 5000mAH Cell

The cells used in a battery are important but they don't give you a complete picture. The case and construction methods as well as the quality of the BMS are also factors.

 

[tomjasz]

I thought that Panasonic was a good brand of cells? I am confused............

One problem anyone around batteries for a decade has seen is counterfeit cells. Often the price of a pack is the first tell. Free shipping deducts at least $75 from the purchase price. Now they're actually selling the pack for $304!

Next, it's WHICH Panasonic cell? How many buyers will actually open the pack to confirm claimed cells are used? What are the cell connections? Is there any cell protection fusing?

It appears this pack is shipped from China, so it can not be returned and you have zero warranty protection. Unless you use PayPal and I'd be certain to confirm PP will warrant your purchase.

There are several users here who are happy with their budget packs and consider the risks an OK gamble. As a former Mirage director, I came to realize billion dollar businesses aren't built on the winners. I don't bet.

 

[EMGX]

It's unlikely that you will find anyone on this forum that has experience with the specific battery that you listed so you will mostly get generic replies.
Regarding if a 52v battery will work with your bike, I don't know but I can say that I have a 48v LiFePO4 battery that charges to 58.4v and came with a 58.8v charger. It works without any error message or other problems on both KT 36v/48v controllers as well as Tongsheng TSDZ2 48v mid drive, YMMV.

I've had good luck with very inexpensive batteries, the oldest is 3 years old and still charges fully and provides excellent performance not distinguishable by me from the two $1000 MSRP Yamaha batteries that I have for my gravel bike. BTW neither of my Yamaha batteries have any UL listing/marking, I see it is often stated on this site that quality batteries are UL listed and those without this certification are dangerous to use, so that obviously isn't the case. I try to be extra careful charging my cheap batteries, charging them on the driveway whereas I usually charge the Yamaha batteries on the kitchen counter. There are a lot of inexpensive ebikes that have great consumer reviews that cost as little as $1000, sometimes less. I'm sure that the batteries in those bikes aren't Yamaha quality $1000 batteries (the charger alone cost well over $200) but apparently they still perform well for the owners over years of use, otherwise we'd hear about it constantly on this site. Again YMMV.

 

[EMGX]

One problem anyone around batteries for a decade has seen is counterfeit cells. Often the price of a pack is the first tell. Free shipping deducts at least $75 from the purchase price. Now they're actually selling the pack for $304!

Next, it's WHICH Panasonic cell? How many buyers will actually open the pack to confirm claimed cells are used? What are the cell connections? Is there any cell protection fusing?

It appears this pack is shipped from China, so it can not be returned and you have zero warranty protection. Unless you use PayPal and I'd be certain to confirm PP will warrant your purchase.

There are several users here who are happy with their budget packs and consider the risks an OK gamble. As a former Mirage director, I came to realize billion dollar businesses aren't built on the winners. I don't bet.

per the ebay listing it ships from California
FWIW the seller has hundreds of positive reviews over the past year and only 4 negative reviews - and a couple of those seem of questionable veracity.

 

[tomjasz]

This is the smallest triangle case I can find to fit my bike with 21700 cells, that I have found so far.

All 21700 52V should be nearly the same size. That should also set off an alarm. The only way to reduce size is by gluing cells with no separation.

I've had good luck with very inexpensive batteries, the oldest is 3 years old and still charges fully and provides excellent performance not distinguishable by me from the two $1000 MSRP Yamaha batteries that I have for my gravel bike.

We've been here before.
We're not discussing performance but rather, safety, longevity, and warranty. These days I tend to stay out of any back and forth on budget packs but in this case, @Nvreloader rides in the N NV desert. A pretty rugged environment that I spent 2 decades camping, traveling, dirtboating, and shooting in. I'd want a pack with cell fusing and separation. I't safety not money that matters to me.

 

[tomjasz]

per the ebay listing it ships from California
FWIW the seller has hundreds of positive reviews over the past year and only 4 negative reviews - and a couple of those seem of questionable veracity.

Again, the wholesale pricing of Panasonic 21000 cells, quality BMS, and proper cell connections make $304 a price one should be alarmed about. Sellers don't offer packs at near-build cost.

How many generic batteries have you owned?

How many actually open the pack and confirm cells?

per the ebay listing it ships from California

Thanks. I lost track of the dates. October is flying by too fast!

 

[EMGX]

I think my cheap batteries have had a pretty rough life, often charged to 100% and left for weeks in that state. Shamefully when testing my 3 year old battery on a bike with a front basket the battery flew out of the basket into a culvert filled with rocks - I probably should have taken it to recycling but I didn't and it still works fine to this day. I don't see how the risk is any greater than buying a $1000 bike which obviously comes with a cheap battery.
Maybe the OP should contact the seller and ask for images showing construction before considering purchase.

I'm not in the market but I'd ride this $1000 ebike any day without undue concerns


EDIT:
above bike also has rim brakes. It must be an unreliable death trap with both a cheap battery and no disc brakes.

 

[tomjasz]

controller on the Wart Hog

Bafang G510 ought to be good to go, but you make an excellent point!

 

[tomjasz]

I think my cheap batteries have had a pretty rough life, often charged to 100% and left for weeks in that state. Shamefully when testing my 3 year old battery on a bike with a front basket the battery flew out of the basket into a culvert filled with rocks - I probably should have taken it to recycling but I didn't and it still works fine to this day. I don't see how the risk is any greater than buying a $1000 bike which obviously comes with a cheap battery.
Maybe the OP should contact the seller and ask for images showing construction before considering purchase.

I'm not in the market but I'd ride this $1000 ebike any day without undue concerns
View attachment 137369

Well, we will just need to agree to disagree. I totally respect your choices. I think the NV desert is harsher but regardless this is an area where we'll never agree. 7 years of taking support and sales calls have made me think otherwise about budget packs. We sold them for a spell. I'm embarrassed to say...

But my opinion and experience certainly doesn't negate your experience. You're a good builder and rider!!

 

[m@Robertson]

Thanks Guys,
Question for you all,
Are there different types of 21700 cells?
This is part of the info posted on these 21700 cells > I thought that Panasonic was a good brand of cells? I am confused............

Description
Normal Voltage: 52V
Rated Capacity:20AH
Battery cell: Panasonic 21700 Class A battery
BMS: 40A
Charge voltage:2-5A
Discharge cut off voltage:58.8V
Configuration: 14S4P （4P*5000mAh=20000mAh=20Ah）
Max Constant Discharge Current: 40A( BMS)
Apply for: 100-1600W Motor
Charger : 58.8V 4A
Battery Cell: 3.7V 5000mAH Cell

Yes there are many different types. I have a custom pack made with Samsung 40T cells and a 70a 'continuous' BMS. That 70A BMS has a 100A 'peak' value (peak is a momentary value usually understood to be only for a few seconds before the BMS pops like a circuit breaker. It will only reset once plugged into a charger at home, so you ride back unpowered). So which rating is the one on sale? They don't say, which I am sure is not an accident. I recently ordered a pack made up of Samsung 50S cells - More power-dense than the 40T. That pack will have a 100 amp continuous BMS (I don't need that much. The manufacturer is out of the 70a units so I decided to trade up rather than down to 60a).

The Samsung 40T is a 4000mah cell with a continuous rated discharge of 35a. The Samsung 50S is a 5000mah cell with a rated discharge of 25a. So the 50S has a higher storage rate and a lower - but still respectable - discharge rate. The 50S pack will be 14S7P which is *huge* for a 21700 pack. 35ah. It will easily be able to handle the 55a continuous draw I will give it without sagging, but the point behind me bringing this up is to provide some detail on how cells can be different.

There is no such thing as a 'Panasonic Class A' battery. Thats marketingspeak meant to soothe the technically-uninitiated. Consider this: You generally don't see Panasonic 21700 cells on the open market. Why? Because Panasonic sells pretty much all of its 21700 output to Tesla. Panasonic shares Gigafactory Nevada with Tesla, in fact, where they make 21700 cells exclusively. So... are you getting used cells culled from a Tesla battery pack (salvaged from one that crashed, for instance)? How do you know if they are really Panasonics in the first place? Its more likely that the 'Panasonic' part is malarkey. This is the problem with buying from Ebay sellers who have zero accountability and purchasers who are not aware of the technical details of batteries.

EDIT: I agree with @tomjasz this has all the hallmarks of a pack with counterfeit cells. All you have to do is slip a thin plastic sheath over any cell and poof its indistinguishable visually from the real thing unless you know how to test them. Buy from a seller with a *real* reputation not an Ebay or AliExpress rating.

 

[tomjasz]

EDIT:
above bike also has rim brakes. It must be an unreliable death trap with both a cheap battery and no disc brakes.

No one said either was a death trap! Just perhaps ill-advised on some builds. BTW I limit my rim-brake build bikes to speeds under 15MPH. Appropriate braking speed for the rim brake bike's design parameters. Having tested all on an MSF course I know what my panic braking distance is. Anything over 20MPH on my bikes with Koolstop eBike pads makes for a situation and braking distance I'm not prepared to accept.

 

[tomjasz]

A point of clarification.
If the seller was offering GENERIC cells and was upfront then perhaps @EMGX may have a point. However, that pack is represented as a brand-name quality cell pack. Other cells are called H Hailong 18650. Clearly, a bogus name and description, using the name of a known case maker NOT a cell manufacturer! Playing on name recognition with no chance of legal ramifications for using a trade name. Again the insulating wall for China sellers.

LITHIUM BATTERY CASE MAKER

Cali eBike and California eBike sold Chinese-made generic cell battery packs. My experience was that 95% of purchasers were happy, but the 5-7% premature failure rate lead California eBikes' original owner (the shop sold and is now under new management) to stop selling them. FAR too high of a failure rate and NO hold on the maker. A $50,000 insurance claim and several other fires to us proved they weren't a good option. The generic cells MAY have been OK with an industry-standard build, but that's never been done.

 

[EMGX]

I get, and respect, what you are saying. Everyone has to decide for themselves that they are comfortable buying and riding. I've just had great experiences doing what I've been doing which includes my Yamaha powered gravel bike and my other cheap DIY bikes. BTW virtually every ride I take from home reaches speeds at least to mid 30s mph downhill coasting and I have absolutely no problems with rim brakes using pads purchased on Amazon for <$10 for 3 sets. I also done a few thousand mile Alaska trip on a 200cc dual sport motorcycle, done couple thousand mile trips on a 170cc scooter and had a lot of fun on rides that others might insist require a giant expensive BMW bike, I'm not interested in that kind of thing.
OP needs to decide for himself what he is comfortable with, it might be different than choices that you or I would make.

 

[Nvreloader]

Guys
Thank you for the information presented,
Here is what I am up against,
I need extra battery's that equal the OEM types I have now,
I have very limited experience with these types of batteries.

1.OEM batteries are 48v-30A controller,
21700 battery has 39 cells/13 in series,
3 in parallel, 15ah/720wh x 2, = Costs of $1400 = shipping.
(IMHO these batteries are over priced, I may be wrong,)


2. A triangle battery/case that is NO larger than 17" x 18" x 7" by 3-1/2" thick,
with 21700 cells, that is equal to or better than the OEM type batteries spec's =
Costs UNK = shipping etc., but cost less than 2 OEM batteries, if possible.

Per information received from Bikonit,
they use LG Chem 21700 Cells,
Advanced BMS System Safer & More Reliable,
Intelligent Dual Battery Balancing Module

I want the same 21700 cells,
so I don't have to buy more/different charging equipment etc.

Tia,
Don

 

[tomjasz]

I want the same 21700 cells,
so I don't have to buy more/different charging equipment etc.

Tia,
Don

Looks to me as you’ve gotten enough good advice and potential downfall information to make a good decision.


All the best!

Tom