Advice needed - 116.8v chargers

[Millhouse_5]

I'm looking to power an electric motorcycle project with a 32 cell system (102v nominal) and I can only find ali express units that are capable of charging that kind of pack.

I current have a luna charger with the option of 80/90/100% total charge selection and 1/2/3/4/5 amp charge rate selection.
Are there any other chargers out there that anyone is aware of that can support my voltage selection with a comparable set of features or will I be stuck with highly customizable high end gear. I'd really like to avoid spending 500 dollars on a charger if possible

 

[john61ct]

As soon as you go over 60V nominal stuff gets pricier, import regs, safety certifications due to the higher dangers.

Then the next big hurdle comes after 21S, in effect approaching 90V

because the components rated for 100V and lower are reasonably priced

those that withstand higher get a lot pricier.

See the specs for very well respected, high power gear, and 21S is commonly their limit.

$500 is darn cheap for a decent charger in the EV world. . .

 

[Pajda]

I'm looking to power an electric motorcycle project with a 32 cell system (102v nominal) and I can only find ali express units that are capable of charging that kind of pack.

I current have a luna charger with the option of 80/90/100% total charge selection and 1/2/3/4/5 amp charge rate selection.
Are there any other chargers out there that anyone is aware of that can support my voltage selection with a comparable set of features or will I be stuck with highly customizable high end gear. I'd really like to avoid spending 500 dollars on a charger if possible

Cheap chargers with 116.8V output can have potentiometer for current settings https://www.aliexpress.com/item/4001234215524.html?spm=a2g0o.productlist.0.0.13ba54b7x8pCnM&algo_pvid=3d629b0f-5b32-4164-a1a5-efc0c591d2fa&algo_exp_id=3d629b0f-5b32-4164-a1a5-efc0c591d2fa-19, if you need changing the voltage you have to choose more expensive CAN controlled charger or you can use internal trim.

 

[markz]

Not sure if it was mentioned but you can hook up a couple or a few Meanwell chargers in series to obtain your voltage.

 

[dominik h]

Two to three Meanwell ELG or HLG in series will do the Job.
I use two with 42V as a waterproof and fanless adjustable charger to charge my 21s pack.

Two with 54V nominal and 58V maximum or three with 42V (36-46V) will do the job.

 

[999zip999]

Meanwells are more trouble free if you don't buy counterfeits as they are many. Twice tried to buy chargers Viva AliExpress twice they had it been returned. Has anyone had success ?

 

[markz]

Of course genuine meanwells are top of the line
Why would you want a knock-off counterfeit?

 

[Millhouse_5]

Cheap chargers with 116.8V output can have potentiometer for current settings https://www.aliexpress.com/item/4001234215524.html?spm=a2g0o.productlist.0.0.13ba54b7x8pCnM&algo_pvid=3d629b0f-5b32-4164-a1a5-efc0c591d2fa&algo_exp_id=3d629b0f-5b32-4164-a1a5-efc0c591d2fa-19, if you need changing the voltage you have to choose more expensive CAN controlled charger or you can use internal trim.

Thanks, I love ali express' inventory, but its sometimes hard to find something you're looking for. That charger is so far the best one (at a surprisingly low price range) i've seen. Thanks for the link.
Not sure what a CAN controlled charger is though, I suppose I may have to do some reading to see if that's a feature I really want to pay for and what kind of price range that would put me in. Any suggestions on where to start/general price range?


As for connecting chargers in series, I'd really rather not. I just don't like the idea of increasing the risk by adding an unnecessary failure point, especially in a charging system.

 

[john61ct]

Some high-end BMS can supervise the charge process

so per-cell voltages are monitored and maybe balanced each cycle

Arduino can also be programmed for custom profiles

different packs get different V/A, CV hold time etc.

CAN is just a simple protocol for comms between the various devices.

 

[Pajda]

One more thing, you say 32s battery, which I suppose means LFP cells? So 116.8V gives 3.65V per cell. I was recently doing cycle life test with some LFP cell samples form CATL and even if they marked with 3.65V as operational voltage limit it does not mean that it should be recomended. I suggest to go down to 3.45-3.5V CV range. With LFP you will not lose to much capacity (up to 5%) in comparison with NMC/NCA chemistries but the impact on the cycle life will be significant. On the other hand, modern NCA/NMC cells already tolerate the full 4.2V charging voltage very well in cyclical and calendar life, and by reducing it lower than 4.15V , you are basically just running out of significant portion of usable capacity.

The second thing is that all modern cells are capable of 0.3C charging rate and again it costs you only your time to go lower. Therefore, it makes sense today to reduce the charging current only if you want to use charge currents > 0.5C from time to time.

This aliexpress store gives you a lot of chargers to choose from.

As an exapmle of "professional" charger you can take this https://www.aliexpress.com/item/1005001954107923.html?spm=a2g0o.store_pc_groupList.8148356.8.5948777casce2l this charger can have variable voltage and current range via CAN bus. But you need a "professional" BMS like OrionBMS which can control it directly, or make your own control system, for example arduino based. They are producing them in more power classes, but chargers with lower charging power are produced only up to cca 100VDC output.

 

[john61ct]

Pajda

have you got a link to a source for new grade-A CATL cells?

 

[Millhouse_5]

Thanks again everyone,

Pajda,
Yes I am using LFP cells and my numbers were 3.65 per cell which i am aware is the absolute max. Thats why I wanted something that could change its voltage on the fly. I love being able to charge to only 80% to save on cycles if I just need to go to work and back and then 100% if I am going for a longer ride.

I also have no desire to charge anywhere near 0.5c as I don't want to rig up a 240v outlet to charge my bike. I'm not in that much of a hurry and I also move a lot being in the military so I don't want to have to install it in every house I live in. so 0.3 or below is fine for me.

Thanks for the link for the charger too. That's more than I was looking at spending, but if i can simply set it to 112v (3.5x32) and just install it on the bike then it might be worth saving a few extra dollars for.

 

[john61ct]

If it works well that is dirt cheap.

 

[Pajda]

Pajda

have you got a link to a source for new grade-A CATL cells?

Actually not I was able to get only few samples for test purposes and most of them was NMC. After comparison between CATL, CALB, Guoxuan and Ecopower I focused more on modern CALB production (not the old plastic case LFP cells) these today offer a good combination of availability and parameters.

 

[john61ct]

In big prismatic LFP, my top choices would be Winston, CALB, GBS and Sinopoly

but since Tesla partnered with CATL hoping they become sourceable.

For the tiny cylindricals, A123 so far seems nothing comes close.

I value build quality consistency and decades' longevity over other factors.