Wanted to share my battery build and get the forum’s advise on the general electronics setup.
I’ll start with the battery and ask the questions in different posts within this thread.
First, I didn’t build the battery, a friend of mine did. It’s his day job, anything involving li-ion packs, from e-bicycle to esk8, RC, etc.
The specs:
12S10P SAMSUNG 18650 25R.
The cells each contain 2.5AH, and are rated 8C (!). This means that I can discharge at 2.5 * 10 * 8 = 200A which should be more than enough for our task.
Dimensions: 20.5 x 24.5 x 7 cm.
Weight: 5850 grams.
I’m using a BMS only for charging, and I asked for a special BMS that allows charging at 15A
I’m going to use this 15A charger, assuming it will go through customs. This should allow me to charge in less than 1.5 hours, which should be nice.
I followed the instructions from @pacificmeister and others in the forum, and bought a lot of equipment for installing between the battery and the motor:
ESC (Hobbywing Seaking 130A, da…)
Self priming water pump
Amp meter
Temperature sensor
Circuit breaker
RC receiver
5V BEC that works on 12S
12V BEC (for pump) that works on 12S (I’m actually still looking for one )
I also got a small waterproof box with transparent top.
My biggest dilemmas are:
Should I mount everything in the same box (with the battery), or should I have a different box just for the ESC (and the two BECs, RC receiver, water pump, temperature sensor)?
Should I transform the battery box so it has a window on top? I think I can do that by cutting a square hole on the top, and gluing a plexiglass sheet on top, keeping it tight to the box with screws.
How do I mount the circuit break? It cuts the circuit when pressing on this button, but how can I make this button accessible quickly and safely? Can I mount it outside the box? I know it is waterproof, but still,… salty water??
Last time I checked, HobbyKing had a 6S 10Ah pack for 69$, which means you can get 20Ah 12S for 276$, this is 80% of the capacity, but at 1/3 of the cost.
Yeah i had my eye on those graphene 15C beauties for half the price for some time now… 2 bad it’s either out of stock or doesnt want to be added to shopping cart
You got to swap numbers, to calculate Ah x $!
840/25=33.6Ah per $!!
Vs. 13.something of Lipos.
Lipo are cheaper but safety etc are to be considered also
Lipo are not cheaper than 18650 , just need to buy at first more cell 18650 for a correct discharge rate but at the end you get a higher capacity pack and it is cheaper ( spot welder less)
Lipo is the easy way good for testing but at the end not so cheap if you built 2-3 pack yourseft of 30q or 25r …
2 people i know nearby me got 4€ deal for Sony VTC 3Ah i think. If ure in europe i can ask for a shop name, idk how marketing goes on this forum. I think shop was in Netherlands.
)
