Battery pack, which 18650?


#1

i ordered a spot welder, i will try to make my battery pack (and board…) for 2019, started to buy staff each month to make easier…

i will stay in 8S, 15 to 20p…, running around 100A at top speed (will test that tomorrow), i guess it will be 5-7A / cell

i am looking at 30Q, 25R , HG2, sanyo GA and Panasonic PF

all the time the 30Q is better, what do you think?

https://lygte-info.dk/review/batteries2012/Common18650comparator.php


#2

I’m on the same boat. I’m just starting to buy supplies for an electric wakeboard. I plan on building my spot welder out of a transformer and some copper nails.
As for the 18650 batteries I got 168 of them for $307 on alibaba including shipping.

They are not name brand but have 2600mah at 3c discharge. Putting them in 12s 14p battery. Still haven’t decided on a motor (maybe sss 56104 500kv) or esc (maybe turnegy 200a).


#3

I just bought the 30q again, I use them in my eskate. You’ll find a lot about 18650s on the e-skate forum.


#4

I’m looking at having our packs built with these cells possibly, lots of juice, buy may be a little overkill, but the battery is the last major part of the build we started now as well. https://eu.nkon.nl/rechargeable/18650-size/sony-us18650vtc5a-flat-top.html

I’m looking at 26Ah, and 40Ah ion packs and they really range in price depending on load need fr om $350 USD built with BMS to $1250 with high end cells and BMS…


#5

I have had so many issues with BMS in the past. (With rc cars and solar setups). Now I just balance charge but the cheap ($30-50) only go up to 6s. I’ve resulted to just use two 6 s battery packs in series. Does anyone else do this?
Maybe I’m just cheap when it comes to the BMS.


#6

Yes, I do this now, most of us do I think. BMS are not that much money in the grand scheme of things though, they are only $100- 150USD to manage $1000 battery pack that should last a long time, but 6S is simple no doubt.


#7

https://www.aliexpress.com/item/10S-15A-BMS-for-36V-li-ion-battery/1195130789.html?spm=2114.search0104.3.1.7048339epADFzn&ws_ab_test=searchweb0_0,searchweb201602_3_10846_10152_10065_10151_10344_10068_10342_10343_10340_10059_10341_10696_100031_10084_10083_10103_524_10618_10307_10624_10623_10622_10621_10620_10134,searchweb201603_30,ppcSwitch_5&algo_expid=7b7789a2-0ce8-4d18-a757-95a134a401a1-0&algo_pvid=7b7789a2-0ce8-4d18-a757-95a134a401a1&priceBeautifyAB=0

This is the bms i use for my e-skate. I need it only for charging, since the vesc controls discharge current. For the e-foil however i use a bms for charge and discharge, since the flier esc does not have any battery protections.


#8

I have built a number of battery packs for ebikes. You need to be wary of batteries with no branding as the mah will be exaggerated. Even suppliers who are selling genuine brand names can be dubious make sure you are getting what you pay for. Using a BMS can be expensive for anything over 100 amps but by splitting packs into 2x 6s you can use a hobby charger and battery alarms to monitor batteries. Watch this videoBms vis
https://youtu.be/pljSZcEwc8Q