There are several combinations of battery + controller that could be fitted to my Rockrider 8.1, but none of them is ideal. An ideal combination should have the following ingredients:
1. Provide enough space for cells and ideally the controller
2. Be safe against burglars
3. Be stealthy
4. Be in a good position for the center of mass and rigidity of the bike
5. Be beautiful
The new battery boxes, such as:
http://www.xofomotor.com/display.asp?id=796
and
http://www.b-t-n.cn/product/1689964693-210753991/electric_bicycle_battery_36v_10ah.html
are very beautiful, they fit many cells and they are in a very good position at the frame. But they cannot fit a controller inside, and they are not very safe. Despite the fact they have a lock, they do not have (apparently to my eyes) a handle, which could be used to secure the battery alongside the bike with say an Abus Bordo. A lock is very insecure. Also, bad people are reported in my city to put silicone on bike locks.
A frog battery is not rigid enough.
A battery such as:
http://www.ciclotekstore.com/b2c/producto/9822085/1/kit-platinium-con-bateria-lf-de-36-v-9-ah-
has a lock, but it cannot be mounted on the water bottle holes. And there is no space for a controller.
A bottle battery has the same problems as the two big boxes (no handle) despite the fact it accepts a specific controller, the S06P (which does not work very well with the motor probably I want to use, the Q100C).
What else?
I have been thinking about adding a seat tube rack:
http://www.pletscher.ch/wEnglisch/pages/Produkte/index.php?IdTreeGroup=13&IdProduct=10&navid=10
which is quite cool, since it has a small box. I have measured the box physically, and both a S06S or 24 18650 would fit in there (quite close in the case of the batteries, but I believe they would fit).
Here there are two options:
A. Put 24 18650 cells inside the box, and bolt the controller below the box. This method is relatively stealthy
B. Put the controller inside the box, and follow the "concept" of d8veh in building a rack, and put a bag on top of the rack, put 18650 cells in a geometry which is low (1 or 2 heights maximum) and put a base (such as those heavy carpets in the cars) above the cells, hiding them, and sew the carpet to the bag, in order to simulate the carpet is really the bottom of the bag. This method is even more stealthy, but it adds a bag, which may attract burglars' interest
Also, weight distribution is not ideal here. It could be the seat tube rack cracks when doing MTB.
And a final solution, which probably is my preferred one, is the following:
C. Buy a big controller case:
http://www.elifebike.com/peng/iview.asp?KeyID=dtpic-2013-7W-BAXN.27YMM
screw it to the water bottle holes of the seat tube, and try to put inside 20 18650 cells (10s2p) and a S06S controller. I am not 100% certain this is possible. For example, in one of the pictures in elifebike, it says the distance between the corners that leave empty space is 14.5cm times 8.3cm. If I stick to the 14.5cm, two 18650 fit in vertical (length of 6.5cm each, a total of 13cm). Since within the 14.5cm the width limit is not 8.3cm, but the total width, 10cm, I believe 5 18650 can be put together. This gives a total of 10 (2 times 5) cells in the first "floor". With 2 floors, I could have my 20 cells. The problem is I still need to fit the controller, which has a height of 3 cm, which added to the 3.6cm of the cells (plus something else for the BMS) is too close to the total height of 7cm. So possibly I would need to "distribute" some cells in the empty spaces to try and leave some space for the controller.
If this could be done, the solution would rank pretty high according to my ranking. It would be pretty safe, especially with "security" screws. There is no handle, but I believe an Abus Bordo could be put around it (and I always could glue a plastic handle on the top). The position in center of gravity is good. The only problem is this solution is not beautiful, and it is not too stealthy (but no solution is going to be stealthy, I believe).
What do you think?
1. Provide enough space for cells and ideally the controller
2. Be safe against burglars
3. Be stealthy
4. Be in a good position for the center of mass and rigidity of the bike
5. Be beautiful
The new battery boxes, such as:
http://www.xofomotor.com/display.asp?id=796
and
http://www.b-t-n.cn/product/1689964693-210753991/electric_bicycle_battery_36v_10ah.html
are very beautiful, they fit many cells and they are in a very good position at the frame. But they cannot fit a controller inside, and they are not very safe. Despite the fact they have a lock, they do not have (apparently to my eyes) a handle, which could be used to secure the battery alongside the bike with say an Abus Bordo. A lock is very insecure. Also, bad people are reported in my city to put silicone on bike locks.
A frog battery is not rigid enough.
A battery such as:
http://www.ciclotekstore.com/b2c/producto/9822085/1/kit-platinium-con-bateria-lf-de-36-v-9-ah-
has a lock, but it cannot be mounted on the water bottle holes. And there is no space for a controller.
A bottle battery has the same problems as the two big boxes (no handle) despite the fact it accepts a specific controller, the S06P (which does not work very well with the motor probably I want to use, the Q100C).
What else?
I have been thinking about adding a seat tube rack:
http://www.pletscher.ch/wEnglisch/pages/Produkte/index.php?IdTreeGroup=13&IdProduct=10&navid=10
which is quite cool, since it has a small box. I have measured the box physically, and both a S06S or 24 18650 would fit in there (quite close in the case of the batteries, but I believe they would fit).
Here there are two options:
A. Put 24 18650 cells inside the box, and bolt the controller below the box. This method is relatively stealthy
B. Put the controller inside the box, and follow the "concept" of d8veh in building a rack, and put a bag on top of the rack, put 18650 cells in a geometry which is low (1 or 2 heights maximum) and put a base (such as those heavy carpets in the cars) above the cells, hiding them, and sew the carpet to the bag, in order to simulate the carpet is really the bottom of the bag. This method is even more stealthy, but it adds a bag, which may attract burglars' interest
Also, weight distribution is not ideal here. It could be the seat tube rack cracks when doing MTB.
And a final solution, which probably is my preferred one, is the following:
C. Buy a big controller case:
http://www.elifebike.com/peng/iview.asp?KeyID=dtpic-2013-7W-BAXN.27YMM
screw it to the water bottle holes of the seat tube, and try to put inside 20 18650 cells (10s2p) and a S06S controller. I am not 100% certain this is possible. For example, in one of the pictures in elifebike, it says the distance between the corners that leave empty space is 14.5cm times 8.3cm. If I stick to the 14.5cm, two 18650 fit in vertical (length of 6.5cm each, a total of 13cm). Since within the 14.5cm the width limit is not 8.3cm, but the total width, 10cm, I believe 5 18650 can be put together. This gives a total of 10 (2 times 5) cells in the first "floor". With 2 floors, I could have my 20 cells. The problem is I still need to fit the controller, which has a height of 3 cm, which added to the 3.6cm of the cells (plus something else for the BMS) is too close to the total height of 7cm. So possibly I would need to "distribute" some cells in the empty spaces to try and leave some space for the controller.
If this could be done, the solution would rank pretty high according to my ranking. It would be pretty safe, especially with "security" screws. There is no handle, but I believe an Abus Bordo could be put around it (and I always could glue a plastic handle on the top). The position in center of gravity is good. The only problem is this solution is not beautiful, and it is not too stealthy (but no solution is going to be stealthy, I believe).
What do you think?
