Which are Better and Why ?
- Thread starter Hipster
- Start date
sunshine_eggo
Happy Breffast!
Neither. Consider that the grey market cells discussed on this site are NOT EV rated. They fail to meet EV requirements for one reason or another.
If you're doing EV, don't cheap out on the cells.
If you're doing EV, don't cheap out on the cells.
thanks but how would i know ? which are the better of the two - or not - i am not looking to cheap out on Cells - but which would you recommend then ? but also why not EVE or CATL cells - i noticed alot of them are being used with good results - at least for storage use -
robby
Photon Vampire
- Joined
- May 1, 2021
- Messages
- 4,235
Almost all of the cells that are in not in Tier 1 Battery packs are Grade B cells. That includes the EVE and CATL cells that you might see floating around for use in DIY Solar. These cells have defects that caused them to be downgraded. They will work when used under light loads like .2C or .5C but will most likely fail quickly is used with a Heavy Load like an EV which can pull 2C or even 4C from a battery.
What is your mobile EV application? Electric Drag-racing at the strip? Mall-scooter? Trolling motor? Wheelchair? Backyard toy?
Even though you say you won't exceed 1C, what happens when you hammer-down with inrush current?
All these variables need to be taken into account before you make a cell or bms decision. Ie, there's a lot more to engineer when you are using motive-power. Using the wrong cells at the outset may make this more expensive than you think.
Even though you say you won't exceed 1C, what happens when you hammer-down with inrush current?
All these variables need to be taken into account before you make a cell or bms decision. Ie, there's a lot more to engineer when you are using motive-power. Using the wrong cells at the outset may make this more expensive than you think.
sunshine_eggo
Happy Breffast!
Might as well just throw the cells in the trash when you get them.
why would you say that
Ok, I get it now. I'm hip to that. Doable.
By no BMS I'm assuming you'll be using an external charger that itself contains the balancing circuitry needed when you actually charge. Popular options in the past were the CellPro chargers and so forth.
Instead of rambling on here, let me direct you to those who actually have this experience of using no-bms in a wheelchair at wheelchairdriver. Op Burgerman (an actual engineer, not just a hobbiest) will set you straight.
WheelchairDriver • View topic - PINNED - Lithium battery conversion/info
everything powerchair
www.wheelchairdriver.com
These guys started out with cylindricals like Headways, (hence the 10 years old first message but still going) but have since move on to the smaller aluminum-cased types since they will fit more ah in a smaller given space.
Give them a lookup for the real scoop.
And in other topics there, instead of a full-on replacement of the existing battery, so-called "Add-on" smaller packs is popular that might hang off the back.
Be prepared to do it right - no shoddy unsafe "drop in" mentality there.
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thanks for that i will check them out - and yes i been using a Cellpro charger PL 8 - still do - does a great job - fast and simple
i also started with the headways - those are going on 8 years now - lost some cap. but still great - need to do a upgrade to new cells with over double the Cap.
good to hear from others here also who have experince with Cells - buying them - which sellers etc,
i also started with the headways - those are going on 8 years now - lost some cap. but still great - need to do a upgrade to new cells with over double the Cap.
good to hear from others here also who have experince with Cells - buying them - which sellers etc,
No problem. The discontinued PL8 is a *real* charger that goes well beyond the hobbiest level. Some have gold-plated theirs.
Note that Burgerman was quite involved in working to get their firmware right, as the original out-of-box capabilites were hobby-level, not only for LFP, but also for lead-acid, which when well understood, for some may make a better choice than LFP. But only when treated properly!
Inquire about his recommended settings when using the PL8 as he has a number of presets you may find valuable.
Note that Burgerman was quite involved in working to get their firmware right, as the original out-of-box capabilites were hobby-level, not only for LFP, but also for lead-acid, which when well understood, for some may make a better choice than LFP. But only when treated properly!
Inquire about his recommended settings when using the PL8 as he has a number of presets you may find valuable.
thank you - its a great charger fast simple balances on the nose - never over charges - what does LFP stand for ?No problem. The discontinued PL8 is a *real* charger that goes well beyond the hobbiest level. Some have gold-plated theirs.
Note that Burgerman was quite involved in working to get their firmware right, as the original out-of-box capabilites were hobby-level, not only for LFP, but also for lead-acid, which when well understood, for some may make a better choice than LFP. But only when treated properly!
Inquire about his recommended settings when using the PL8 as he has a number of presets you may find valuable.
sunshine_eggo
Happy Breffast!
ah... balance charger... M'kay. That works.
Well, it is a bms - only it's all contained in the charger, not the battery. And in this motive-power application, having the balance in the charger is the RIGHT place.
Lurkers - the PL8 is not a toy. You don't buy one and use a crap-tastic power supply with it.
Try this with a small amperage iMax hobby counterfeit, and your results may vary - widely.
Lurkers - the PL8 is not a toy. You don't buy one and use a crap-tastic power supply with it.
Try this with a small amperage iMax hobby counterfeit, and your results may vary - widely.
They are discussing that very thing recently. Unfortunately, the powers that be involved with the PL8 series may have moved on.
Of course, instead of relying on internal bleeders, one has the option of using a dump-load regenerative charge to another battery.
Heh, at first glance to some, it's just a "lipo charger", which it will do - along with about 12 other chemistries. You just have to know how to use it.
Of course, instead of relying on internal bleeders, one has the option of using a dump-load regenerative charge to another battery.
Heh, at first glance to some, it's just a "lipo charger", which it will do - along with about 12 other chemistries. You just have to know how to use it.
