SZZS specific CEF50-main thread (initial builds and troubleshooting related only)

TCFlowClyde

Active member
Feb 26, 2022
1,350
876
Mesa, AZ
I mean it will surely be a mess to get the right fitment and it expands quiet a lot if u aim to spray it directly into frame.
A styrofoam block only needs to be cut to length if you stand the batteries like Lanton said, will sit firmly.
Could be. But the original mount holes will give easier access to the target areas for spray. And the toptube cover will give a little better spraying access at the top of the battery. Plus, they're tubular, closed-cell foam to purchase. 3-4" diameter could be key. Or use both. Shoot the spray just to hold the closed-cell foam inserts into place? 👍 I like it!🫡
PXL_20230613_180752756.jpg
 

TCFlowClyde

Active member
Feb 26, 2022
1,350
876
Mesa, AZ
I mean it will surely be a mess to get the right fitment and it expands quiet a lot if u aim to spray it directly into frame.
A styrofoam block only needs to be cut to length if you stand the batteries like Lanton said, will sit firmly.
Or maybe you are right...no foam spray...just the closed cell foam inserts. 🤙

There is about about a 4-5" space between the motor mount area where it's locked in. It'll have resistive counter pressure with aerated CC foam inserts. Then at the top, use 6-10" insert in the head tube area. Plus, CC will mold a little better to inner tube contours and cable feeds. Maybe be a tighter fit with some extra water resistance 👍

Good job team!🤛 Future project for sure!🛸

Just outta 💸💸💸 for my budget now in order to buy a proper battery welder that I can trust and learn the skill. But huge weight savings.👑
 

Bengy22

Member
Aug 25, 2022
125
83
USA
Nice alternative! 2.2 kgs/4.85 lbs. 28Ax3px10s =840 Wh!

Vs. SZZS 720 Wh 4.0 kgs/8.18 lbs.

4.0 kg - 2.2 kg = 1.8 kg/3.97 lbs. Savings? 🫣

Holy sh$$t! I can shave off this much weight?💪

Is the casing really that much extra weight?🤔
1 x 21700 cell = 60 g.
60 g x 30 cells (3p/10s) = 1800 g + 400 BMS/wrap = 2200 g.

It fits solidly in the frame with no fasteners? Wouldn't you still need a bracket at both ends to plug and isolate movement up and down the tube?

The next big question. How to save that much weight, there must be a light-weight retaining solution to firmly hold the battery in place?

Someone really smart and creative, what are some possible solutions?🍻
The math isn't adding up with what they claim, with 30 cells total each 21700 would need 28wh. The very best cells on the market only offer 20.88wh right now with your way more common 5ah cells hitting 18.5wh. Originally they claimed it was a 10s6p or 60 cells, that's roughly 4.66ah per cell so way more likely, I assume the 3p claim was a mistake.

Your assumed weight would be roughly 550wh with a common 5ah cell. Get your hands on a lg m58t or vapcell F58 rewrap (5.8ah) and that could be 625wh. Samsung 50e's are around 69g each though, 5.8ah cells are closer to 74g each. So slightly heavier than your assumption.

If you went to a 10s4p pack though that's 740wh for the 5ah cells, at 2760g plus the other materials. Go with the 5.8ah option and you can get another 100wh or 835wh but slightly more weight at 2960g for just the cells.
 

TCFlowClyde

Active member
Feb 26, 2022
1,350
876
Mesa, AZ
The math isn't adding up with what they claim, with 30 cells total each 21700 would need 28wh. The very best cells on the market only offer 20.88wh right now with your way more common 5ah cells hitting 18.5wh. Originally they claimed it was a 10s6p or 60 cells, that's roughly 4.66ah per cell so way more likely, I assume the 3p claim was a mistake.

Your assumed weight would be roughly 550wh with a common 5ah cell. Get your hands on a lg m58t or vapcell F58 rewrap (5.8ah) and that could be 625wh. Samsung 50e's are around 69g each though, 5.8ah cells are closer to 74g each. So slightly heavier than your assumption.

If you went to a 10s4p pack though that's 740wh for the 5ah cells, at 2760g plus the other materials. Go with the 5.8ah option and you can get another 100wh or 835wh but slightly more weight at 2960g for just the cells.
Ah thanks, I knew my math was too good to be true!😁

I still like the updated calculations also! Samsung 10s4p softpack:

👉 2.8 kg 740 Wh - 4.0 kg Wh
= 1.2 kg/2.65 lbs. 🤛

Wow! That's still a small chunk of weight!💪🍻
 
Last edited:

Bengy22

Member
Aug 25, 2022
125
83
USA
Ah thanks, I knew my math was too good to be true!😁

I like it the updated calculations too! Samsung 10s4p softpack:

👉 2.8 kg 740 Wh - 4.0 kg Wh
= 1.2 kg/2.65 lbs. 🤛

Wow! That's still a small chunk of weight!💪🍻
For sure, although probably close to 2 lbs less once you get the bms and cells all welded together but good amount of weight savings you just need to make sure its well secured in the frame. I know a lot of people talked about not wanting the larger 720wh pack but delays made them choose it. The 10s3p with lg m58t's I think would interest a lot of people, roughly probably 2.5kg once all welded up and still 625wh for a good middle ground in capacity. 1.5kg in weight savings could maybe get some under the 40 lbs mark!
 

TCFlowClyde

Active member
Feb 26, 2022
1,350
876
Mesa, AZ
For sure, although probably close to 2 lbs less once you get the bms and cells all welded together but good amount of weight savings you just need to make sure its well secured in the frame. I know a lot of people talked about not wanting the larger 720wh pack but delays made them choose it. The 10s3p with lg m58t's I think would interest a lot of people, roughly probably 2.5kg once all welded up and still 625wh for a good middle ground in capacity. 1.5kg in weight savings could maybe get some under the 40 lbs mark!
Yeah I think @Lee. did that with his 625Wh batteries. I queried him to get a response on how his soft pack fitment went. The range seems to be quite good with M820 in general. And that would put my Enduro build at a nifty 43.5 lbs dry weight. Worth it! IMHO🦄
 

TCFlowClyde

Active member
Feb 26, 2022
1,350
876
Mesa, AZ
For sure, although probably close to 2 lbs less once you get the bms and cells all welded together but good amount of weight savings you just need to make sure its well secured in the frame. I know a lot of people talked about not wanting the larger 720wh pack but delays made them choose it. The 10s3p with lg m58t's I think would interest a lot of people, roughly probably 2.5kg once all welded up and still 625wh for a good middle ground in capacity. 1.5kg in weight savings could maybe get some under the 40 lbs mark!
So this 21700? Curious cost per cell in USD? Are they readily available?

Screenshot_20230613-124024.png
 

Bengy22

Member
Aug 25, 2022
125
83
USA
So this 21700? Curious cost per cell in USD? Are they readily available?

View attachment 117684
Yes that cell, I couldn't find it available in the USA but the Vapcell F58 is a re-wrap of it. They have an official ali-express webpage for them though linked on their sites page. Not cheap at roughly $10/p but goes down with the more you buy at once like other cells. They must have just very recently started selling them though as I've been on the lookout for them for a while now and just noticed it a few days ago and the listing only has 6 sales. I got in contact with Mooch a very well known battery tester, and informed him of this as he wasn't aware the US market had access to them yet. He ordered a few and said he should have testing out on them in a month. https://www.vapcelltech.com/h-pd-174.html

There's also the Vapcell F56 that 18650batterystore has, no idea what cell that could be though or maybe its the lower quality rejects at 5.6ah. But you can also buy those today
 

TCFlowClyde

Active member
Feb 26, 2022
1,350
876
Mesa, AZ
Yes that cell, I couldn't find it available in the USA but the Vapcell F58 is a re-wrap of it. They have an official ali-express webpage for them though linked on their sites page. Not cheap at roughly $10/p but goes down with the more you buy at once like other cells. They must have just very recently started selling them though as I've been on the lookout for them for a while now and just noticed it a few days ago and the listing only has 6 sales. I got in contact with Mooch a very well known battery tester, and informed him of this as he wasn't aware the US market had access to them yet. He ordered a few and said he should have testing out on them in a month. https://www.vapcelltech.com/h-pd-174.html

There's also the Vapcell F56 that 18650batterystore has, no idea what cell that could be though or maybe its the lower quality rejects at 5.6ah. But you can also buy those today
So, 740Wh 10s4p = 40 21700-M58T cells x $10/ea. = $400. Not bad!😎
 

LAnton

Active member
May 12, 2022
553
462
Russia
Apologies. I see the following are confirmed:😇

👍36V x 28 A = 1,008 Wh
👍Total battery weight = 2.2 kg
👍And the BMS works with the M820 motor.

The link is AliExpress for the battery. I couldn't get the link to work.

🤔What is the retailer name on AliExpress?
I did not correctly write 2.2kg x 2 = 4.4 kg :). I showed an example. That you can install 28A.
 

spokémon

Member
Apr 4, 2023
191
99
Australia
I did not correctly write 2.2kg x 2 = 4.4 kg :). I showed an example. That you can install 28A.
Thank you @LAnton
If I'm understanding correctly, you have 2 battery packs.
Each pack is 10s3p 36v 14Ah 504Wh 21700 cells 230x75x60mm 2.2kg

For those of us on a diet, this is fantastic! Bafang F014 410Wh battery pack is 470x63x52mm 2.55kg

Apart from the obvious Wh/kg ratio, I'm as much interested in the weight distribution of LAnton 's package :)
The length 230mm vs 470mm is half the length! This means with LAntons pack, ALL the weight can be mounted much closer to the bottom bracket. This should improve bike handling, jumping, berms etc...
 

LAnton

Active member
May 12, 2022
553
462
Russia
Thank you @LAnton
If I'm understanding correctly, you have 2 battery packs.
Each pack is 10s3p 36v 14Ah 504Wh 21700 cells 230x75x60mm 2.2kg

For those of us on a diet, this is fantastic! Bafang F014 410Wh battery pack is 470x63x52mm 2.55kg

Apart from the obvious Wh/kg ratio, I'm as much interested in the weight distribution of LAnton 's package :)
The length 230mm vs 470mm is half the length! This means with LAntons pack, ALL the weight can be mounted much closer to the bottom bracket. This should improve bike handling, jumping, berms etc...
You understand that the manufacturer makes safe batteries. Only we ourselves can make the battery lighter and safer.

WhatsApp Image 2023-06-14 at 14.47.03.jpeg WhatsApp Image 2023-06-14 at 14.47.04 (1).jpeg WhatsApp Image 2023-06-14 at 14.47.04 (2).jpeg WhatsApp Image 2023-06-14 at 14.47.04.jpeg
 

LAnton

Active member
May 12, 2022
553
462
Russia
These packs not looks safe unfortunately. To prevent wibrarions under mtb ride.. one guy made similar with dengfu frame and catch fire 😅
It's not funny :-( The battery should be made by a professional, not a guy on dengfu. A modern battery can catch fire if it is damaged. Modern cells have protection in the form of a valve. If the battery overheats, the valve is damaged. The battery is also protected by BMS
 

giczalec

Member
Jan 26, 2023
11
24
EU
It's not funny :-( The battery should be made by a professional, not a guy on dengfu. A modern battery can catch fire if it is damaged. Modern cells have protection in the form of a valve. If the battery overheats, the valve is damaged. The battery is also protected by BMS
Yea it was made by customer. Better to let do it by professional than stayed dangerous
 

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