Thanks Shawn! Built my first battery, thanks to your very thorough instructions. I viewed this video several times until i could understand the concept. Wish you great abundance for your selfless service to the community.
Jose- I have filled your order but the shipping algorythmn charged you $7 too much for shipping. Can I have your PayPal account so I can refund?. Send to shawnwiththewind@gmail.com
Really helpful! with out your videos it would of been allot harder to build my 20s/20p 72v/55ah pack, no bms just a weekly balance check up with the hobby charger, thank Shawn.
Very straight forward! My BMS came for 4S came with 1 black and 4 red sensor wires. Assuming that should work exactly the same way, but perhaps more physically correct since black goes to black and 4 reds go to 4 pos cells.
@@shawname2 Hi Shawn, yes on the book. Like it! Jehu's group buy 2 didn't go so well, so I had to buy new batteries, ebay. Just put the pack together per your instructions. Voltage tests confirm I have built spot on. Thanks so much for your help! Next is wiring the BMS and the power leads.
ingenious! the blocks + magnets + plates do add weight over soldering. I may try this but I need to know lots of things, what to buy, which controller, etc. to make an ebike. Are these details in your book? Also I'm concerned nut/bolts may come lose because of bike vibration? How to prevent that? Of course you should inspect all nuts on a bike frequently, so I assume now you must also inspect the battery nuts frequently. Which is ok as long as you remember to do it.
The bolts are nylon and the nuts don't work loose. My $3 ebook is about how to build a battery and how to do the math - but not about how to build an ebike. But building an ebike is wasy- just get a kit from Amazon or ebay. I built one yesterday morning. The kits have everything including instructions. For a first ebike they are great!
I wish there was another word used other than "sensor" wire. The wires monitor and provide a way to balance the individual cells. A sensor has leads connected to a device that displays, stores, monitor, or some dose some function with the signal created by sensor. The batteries are not in that case a sensor. I would call the battery pack's small wires equalization wires. That is their purpose ultimately.
Good point Snowy, I agree, there are no sensors involved. The only way that it can justified being called a sensor wire is because it is sensing the batteries voltage.
Shawn McCarty We all use different language sometimes. My culture practically makes it an art form.lol. That sensor is called a volt meter and measures potential differences with wires called leads and in units of volts. Some newbies are confused when we say balancing the batteries or balance charging. Really it is equalization of the cells to the same potentials and that can occur on charging or discharging cycle by the wire leads. Ergo calling them a name related to their purpose helps the novice. Great build by the way.
Thank you Snowy. As I think about it I did coin the term "sensor wires" some time ago and have always called them that without thought. I appreciate accuracy in language and agree that calling them "equalization wires" would be more accurate. I'll change terms!
Thanks! It's been a long process of refinement. To answer your question, it depends. For a normal sub 20 amp hour draw ebike battery 12 gauge will work. For say a 30 amp hour draw battery, I would use 10 gauge. I use multi stranded flexible silicone wire when the wire has to bend tightly, and automotive wire when it doesn't. When in doubt I use this calculator: www.calculator.net/voltage-drop-calculator.html It's good to shoot for a voltage drop of under 3% when under the heaviest load the battery will face. Good luck!
I like the icharger series best for quality. Cheaper ones can be found at Hobby King. A 10S hobby charger will manage a 10S battery. Have you seen my video on "How to build a safe and better lithium battery without a bms"?
+Shawn McCarty Ok great. I have seen that video, very interesting. It definitely seems like a more reliable way to manage a battery. Your videos have been a big help thus far!
If I'm creating a 36V (10S) battery, how would you recommend monitoring the cell voltages? As far as I can tell, all the cell checkers/loggers only go up to 8S. Would I have to break the battery into two smaller packs, or does someone actually make a 10S voltage checker? Thanks!
Hi Shawn Do you have any advice for me to reduce the size of the battery? If I use these cells I will end with a huge battery, I wish you would advise me what cells use and how and in what order to arrange them ...... and again thank you very much
Tamir, If your goal is to build the smallest battery pack possible you need to use cells with a very high energy density. The Panasonic 3400mah cell is a good example. Also you would want to spot weld the battery together, as it takes up to 20% less space than using rebuildable batterblocs. In order for me to advise you on how to configure the cells, you need to tell me what your final voltage and amp hours are and your maximum current draw.
if you balace the 12 battery pack with a 6cell balancer, i presume you connecting each wire to two batteries in serie. will the two batteries not be unbalanced ?
No that is not how it is done- you will melt the sensor wires. You charge the pack in two halves. My $3 ebook explains in detail. www.batteryblocs.com/groceries/the-hobbyists-guide/
They need to be magnetic. And Cheap. The plates are so massive and the distances so short that being made of the most conductive metals is not necessary. So they are made of zinc plated 1010 steel.
The amps are measured by multiplying the amp rating of the batteries you are using by the number of batteries in each parallel group. So if you are using 10 amp batteries and have a 8P cell parallel group you have an 80 amp battery.
What cells are you using Tamir? Are they 2600mah, 3000mah? The amperage in the cells determines how many you need to reach the 15 amp hour that you are seeking.
So if you start with the 2600 mah cells, they are 2.6 amp hours each. You want 15 amp hours. 15/2.6 is 5.7, make it 6 cells wired in parallel. Now you need to know how many bunches of 6P cells you need to make. The nominal voltage of the cells is 3.6 volts, so 48/3.6 is 13.3. So you would wire either 13 or 14 groups of 6 cells to each other in series. Shawn
