18650 Cell Questions

bobbill

bobbill

100 W
Joined
Apr 9, 2018
Messages
256
Location
SE MN (Winona) USA
I bought 30 cells to make two no-weld packs. The cells vary now in voltage from 2.3 to 4.3 volts and are separated into approx groups by measured voltage.

Two, packs were 30S 3P...

I tried Vruzend route and they failed, me, and the firm was silent.

So I bought a made pack and it works fine...and have these cells sitting.

Can I still use? They are now two years old and, as noted, have various voltages.

Or; should I sell or make a number of laptop battery packs for computers I have?

Am so clueless!, but like the quiet and no stink bike rides.
 
Group the low voltages together.
Charge them up to storage voltage. Let them sit and measure voltage drop over time or test them to find out their health.

I would group the low voltages together into a string, but another theory is to sprinkle the low voltages into one low voltage per healthy string. Install a cell log to keep tabs on the voltages.

The high voltages, 4.3V would do the same. Decrease the voltages to 3.6V or 3.7V and let them sit measuring voltage drop over time or test them to find out their health.

I would decrease the 4.2V and anything over 3.7V down to 3.6V. Put them together
I would increase the 3.2V and higher to 3.6 or 3.7 V. Put them together.
 
Mark, Thanks.

Really, if they lose why decrease?

And, how do you decrease volts? No gots anything uses cells, save bike and laptop and both have packs///
 
If you build a pack that is not balanced ..even a laptop pack...you run the risk of a major fire ...( houses have been burned down),
So do some more research before you undertake something beyond your expertise.
There are plenty of searchable threads on here explaining the essentials..
.... But as a starting point for reducing the voltage of a cell....
....put it in a flashlight !!....... ( and there are even simpler ways !)
 
You connect the battery to something like a light that will draw power out of the battery to reduce the charge. It does not need to be a flashlight. These type of cells are damaged is you let them set fully charged or let one get to low. It is common knowledge to store these in a mid range and you need to check them to make sure non of them are discharging to low. Do not store and ignore.
 
Zero thanks. So any light will do...but how does charge level compare to L-ions used for cameras, where charge varies?

Some say nada re storage...and the bat pack I bought says nada re storage either..., much less load in each cell...I know I sound anal, and am, but all is so confusing...

So, I just attach cells to DC bulb to get down to say 3.4 volts...?

If the cells diminish in time, why not let sit?
 
Cells are fundamentally damaged by time spent at full charge. Shortens their overall lifetime.
 
Bob...so when the snow hits the fan, I take the battery pack down to 30 and store in cool place...still working on some way to lower change in some cells...PIA. and thanks.
 
Mark, am gent who needs simple...never did much with electricity after pith balls in HS physics...you refer to resister diode thingies, I assume.
All I ever did what hand tap to another battery for few seconds - and hope for best.

Am just a dodger who tried making packs and failed...and now want to use those cells, which were spendy.

Thanks...

And, it just occurred to me, all applies to any Lithium Ion based battery, regardless of use...camera, models, cars and bikes.
 
Many away to skin a cat dodger man.

Get the high voltages down, get the low voltages up.

More reading, like the fella who used heaters to reduce voltages, or another fella used light bulbs, or a fella who used a pin + rc charger to increase a cell in a lipo pack (rather then take forever to balance charge), or another who used a cell phone charger because it was cheap from thrift store but stated 5V so had to keep an eye on things closely, many a story dodger man.

I would suggest buying an RC charger and setting up the voltages appropriately for charging and discharging. Cheap enough, https://hobbyking.com/en_us/batteries-chargers/chargers/ac-dc.html?___store=en_us
 
Dig and thanks. Thing is, if I buy one of those RC chargers, and have the goods hereabouts, I will not learn much, if that makes sense...
 
This is what I found... https://hobbyking.com/en_us/imax-b6-dc-charger-5a-50w-copy.html?queryID=385f1323fe812d770911cc17a84606d1&objectID=53604&indexName=hbk_live_magento_en_us_products

but need to learn...
 
bobbill said:
I bought 30 cells to make two no-weld packs. The cells vary now in voltage from 2.3 to 4.3 volts and are separated into approx groups by measured voltage.

Two, packs were 30S 3P...

I tried Vruzend route and they failed, me, and the firm was silent.

So I bought a made pack and it works fine...and have these cells sitting.

Can I still use? They are now two years old and, as noted, have various voltages.

Or; should I sell or make a number of laptop battery packs for computers I have?

Am so clueless!, but like the quiet and no stink bike rides.
Click to expand...

30S? 30 cells in series? And 3 parallell?
 
you never spotwelded the vruzend cells, click on , Battery Magnets, in my signature. its simple and basic to build a battery with them
 
I did two Vruzend kits, the early and the latest...both failed..

The latter one was so out of whack I had to disassemble to measure each cell. Never again.

Fool me once...shame on you fool me twice shame on me...I learned.

The first kit had two hot cells in the center and had to tear the pack apart to get to them. The heat ruined the frame work, and was able to redo...no thanks to Vruzend, which did not supply components for repair and told me to "get a brain."

Also used copper not the SS/nickel garbage Vruzend sent...

The second pack ran for about a mile and quit. Both BMS stopped the power; and once that happens the BMSs need to be reset...still working to find out how to do that.

So, now I have two sets of cells from two 10S3P 36v packs to even out and store...right now all cells sitting, separated by volts in metal ammo box. Some 12 different groups.

While the assembled small 36v Chinese pack runs fine...there is more but most is not good for Vruzend. Dingers.

Did not know about Ness packs or would have use them instead...and here we are.

The controller, motor, and readout thing are all Grin...they at least help and know their products and back them.

Please do not offer Vruzend kudos up here. Losers to me and am beyond that crew.
 
It's hard from here to sort what happened to the center cells, but it was likely builder error. Not the product.
Who replied with "get a brain"? I'm well aquainted with the princicples at Vruzend. That does NOT read like something they would have responded with. I can't imagine them making good on your problem battey kits. I can imagine getting frustrated with a builder that calls a CA3/CA2 a "readout thing".
 
It very well could have been my error as builder, but I will say this...I built carefully and even replace the steel with copper strips for both S and P connections, even making sure each cell contact registered on my little voltmeter...continuity etc.

Then tried the Chinese pack and it it worked fine...

One would think Vruzend would provide at least some replacement parts...

I have kept the emails, but not worth my time now. Screw them.

Appreciate the response...I will likely muddle through...and as Murphy's Law goes, likely fix as the snow arrives, here in lovely MN, after a summer of not riding bike...

BTW, the one pack ran until the BMS shut it down, likely due to cell imbalance, which I noted in another thread and got onto the Chinese Pack...which I should have bought, or the Ness items.

You know anyone wants to play with the Vruz junk, I have and will peddle, save the BMSs, which I think I can recalibrate to zero...for 36v packs...I think...like I said, fool me once etc. Am learning.
 
Here's my cell level battery charging...

https://electricbikereview.com/forums/attachments/img_0310-jpeg.46586/
 
Too spendy for what I need, but love it.

So 80% will hold pack till March?

Nagging ? if these things gradually lose volts, why is full charge so bad/

Seems Spinning Magnets explained but did not save that link...and on spare computer and no access now...computer troubles...chirping no screen...
 
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