Dolphin 17.25 ah, 50A, 70 cells build

[eAdrian]

This build is an attempt of modification the standard dolphin case to fit 70 cells.
The case normally holds max 54 cells having 48-52V configuration.

The goal is to get 14s5p (52V) configuration with large 50A BMS fit into the case giving 17.25 ah capacity.
This battery will feed MXUS 3000 V3 4T motor fitting into regular MTB - White XC 275 medium size frame.

I have done this because:

• I like the look of this case compared to other down tube cases, home made cases , triangle bags
• Really solid case protecting the battery & BMS.
• Easy to mount on the frame using the bottle mounting screws
• I believe it will take less time to modify the case than building new one from scratch
• I want to be able to remove the battery for charging

Components:

• Empty dolphin case
• 70 pcs Samsung 35E 10A discharge capable 18650 cells
• HCX-D131 BMS 50A discharge (120x80x25mm)
• Maxi fuse holder
• Maxi 70A fuse
• Awg 10 wires
• XT60 connectors

 

[eAdrian]

This is prototype putting 70 cells inside.

 

[cal3thousand]

I like that you are being adventurous and making something yourself.

Just wanted to know if you are aware that there is a newer version of the Dolphin battery (some referring to it as a whale) that holds more cells in the exact same design, albeit larger.

 

[eAdrian]

This is the 14S5P battery with 50A BMS.
The charging wires are also awg 10 because I did not have anything else at the moment,
The charger will charge battery at 6A.

 

[eAdrian]

I like that you are being adventurous and making something yourself.

Just wanted to know if you are aware that there is a newer version of the Dolphin battery (some referring to it as a whale) that holds more cells in the exact same design, albeit larger.

Yes, I have seen them quite recently. But they were not on sale when I ordered my cases.
Here is the whale fitting 65 cells.
http://www.aliexpress.com/store/product/48V-or-36V-electric-bicylce-battery-storage-box-and-e-bike-down-tube-battery-case-with/1816683_32694174743.html

 

[eAdrian]

Final mounting:

Bike performs very well with this battery.
2000W on the LCD3 display. (~35A with kunteng controller, rated max to 60A).
Torque provoking wheelies.
Max speed: 58 km / h.
Battery range is >30km mixed driving.

 

[eAdrian]

Initially I did not manage to close the case due to the bastardly thick awg 10 wires.
So the wires for charge and discharge goes outside the case. They are duct taped on the top of the case.

Since the case is lacking bottom screws for keeping the halves together, there is also duct tape in the bottom of the battery.

The case is closed together with screws, duct tape and the bottle holder.
I will potentially add a metallic clamp if I start to see issues. So far heavy riding in forest did not drop the battery or make it move.

 

[hedsik]

Good grief this is awesome.
So much juice in so little packaging!