Chinese 84V (72V/20S) Chargers from Ebay -- thoughts, experiences

jas67

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Oct 13, 2021
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As my EV-converted Vespa will have 70AH (72V/20S) of battery capacity, I'd like to get a higher-current charger (currently have a 4A and an 8A, which I've used in parallel for 12A).

I'm looking at this 15A model:
https://www.ebay.com/itm/234812216422

and this 25A model:
https://www.ebay.com/itm/125222975763

The 25A one requires 220/240V input, which isn't a huge problem for me, as I can easily add a 240V outlet in my garage for it.

The 25A is 2X the money. I can always just use the 15A in parallel with my other two charges to get 27A, even thought it would be a bit of a PITA to wire up all three. I could just mount them all to a board and put one longer charging lead on it.

Choices aside, has anyone here used any of these charges? Any concerns about the quality and safety of them. The chargers I'm already using are Chinese-made units from Amazon.
 
one rule: Never trust 100% at Chinese plastic chargers with fan cooling, just trust at 50%.. After some time use, fan stops working and charger go out of mind output :flame: go aluminium case charger :bolt: :bolt:

Vespa scooter is a EU precious value! at USA is a rare precious thing. If You ship a Vespa to USA they will pay a lot for it!! (USA are consumerism people that like new tech things and art!)
Are there any Vespas @ CN Hong Kong or Beijing? :pancake:

Good ideia to parallel chargers :idea:
The low cost fast charging solution is to add extra chargers (current sources) in parallel.
Easy to do with spliter cable connections
I've seen one person used x4 chargers 2A to charge citycoco scooter 12Ah battery, so charge rate is 8A for a 12Ah battery..a semi fast charge. :bolt:

A good rule is to keep charging rate for normal battery under 1/2C
If Your cells support high rate charging, soo U are allowed to do it. (A123 LiFe cell take +10A charge, this means 4C-5C charge for 8min full charge. Imagine only 8min charge time for your battery or only 3min to charge 50%!! maybe perfect system..)

yes U are can use in parallel 15A plus 8A plus 4A chargers in parallel. this means 27A charge current for a 70Ah battery
soo using math 70Ah/27A equals 2,6hours = 156min charge time ideal, but dived by x0,8 equals 195minuts, and add extra final top charge time at declive current source , maybe battery 0-100%charged in 220minuts means 3,6Hours or 3hours and 39minutes and only 1hour 30minutes to charge a 50% energy packet :bolt:

doin math on time calculations, are U confused at this moment? :warn:
 
carefull when using x3 paralell chargers 15A +8A +4A at AC :warn:
doin math 27A x 84V equals 2250W power draw form chargers combined. if charger DC-DC converter has 85% efficiency soo, form AC main socket you will draw 2250W/0,85 equals to 2670W from AC plug. soo U can't do this type of connection.. connect 15A charger to one AC socket and the other two 8A+4A chargers to other AC socket..
or just redesign your home power supply system and add parallel cables to specific AC supply socket in order to handle 2670W

keep up your AC home electricity :bolt:
 
batteryGOLD said:
carefull when using x3 paralell chargers 15A +8A +4A at AC :warn:
doin math 27A x 84V equals 2250W power draw form chargers combined. if charger DC-DC converter has 85% efficiency soo, form AC main socket you will draw 2250W/0,85 equals to 2670W from AC plug. soo U can't do this type of connection.. connect 15A charger to one AC socket and the other two 8A+4A chargers to other AC socket..
or just redesign your home power supply system and add parallel cables to specific AC supply socket in order to handle 2670W

keep up your AC home electricity :bolt:


I've already thought of this (I'm an electrical engineer), not a problem. The outlets in my garage are two duplex outlets per location with two different 20A circuits. I'll plug the 15A one into one of them, and the other two into the other.
 
I just ordered the 15A one. It alone will satisfy my needs most of the time. If I need a quicker charge, I'll hook up all three.

Even the 4A one is good enough for an overnight charge from 20% back to 80%.

Part of why I am adding battery capacity is to be able to aways keep my SOC between 20% and 80% for maximum battery life.
 
jas67 said:
Even the 4A one is good enough for an overnight charge from 20% back to 80%.

The phrase is "Who needs fast charging and why?"
Better to charge any battery as slow as possible :thumb:

U have a 70Ah battery, lets say U charge from 20% to 80% this means 80 less 20 equals a 60% charge packet
Soo 60% of 70Ah equals 42Ah
charging 42Ah @ rate 4A means (42Ah/4A = 10,5hours charge time, 630minutes or 10hours&30minutes)

lets say U need you Vespa battery ready at 9:00am morning. this means U need to start charging 10h&30min before.
This means,at final of the day, if your battery is at 20% SOC, U need to start charging it at 22:30 (EU clock, 1h30min before midnigth) for a overnight charge.
This is time calculation for 60% packet to go from 20%@22:30 and reach 80% next morning 9:00am @4A charge rate

more time math In order to top up 20% of battery is around 14Ah, and charging @ 4A rate means 14Ah/4 equals 3,5hours plus final current decline when doing top charging. so maybe goes up to 4hours to reach 100% SOC

this means if at 9:00am is at 80% SOC and U fall into asleep and wake up at 13:00h (midday+1hour) means U have a 100% charged battery!!

Engineers play with math just for fun!!
 
if you charge every day Your Vespa from 20% to 80% means Ur riding style spends 42Ah capacity
This means 42Ah x 72V = aprox 3KW energy packet

google source "An average electric car consumes approximately 0,20 kWh/km.
but a car is a lot more heavy than a scooter
more google
"A typical efficient electric scooter can achieve consumption of 0.018 kWh/km (5). Figure 5.22/03/2022"

soo doin some range math. if U have a 3000Wh power slot , and U ride a scooter using 18Wh per Km consumption, this means 3000/18 equals 167Km range, but this maybe extreme ideal case or just at 25Km/h flat(no variable accelarations, just constant speed,no wind(or maybe at vacuum.. this way consumption is ZERO Wh after reaching cruise speed))
If U ride escooter at 50Km/h(unknown miles per hour..) this means power consumption could go to 40 or +50Wh per Km (depends on driving style(and wind), the more U acellarate the more consumption, if U do slow grade progressive acceleration, range will be longer. similar to a car, if you go slow on accelerator, U save fuel! U dont need to go full throttle al time!)
This means 3000/50 equals 75-60Km range using battery from 80% to 20% slot (or maybe 50Km range iF U are sport driver)

How many Km's(miles to Km racio 1,61) U drive every day??

By the way, nice buy for tha 15A charger :bolt: :bolt:
the other option 25A will overload any AC socket :lowbatt:

Have a nice day :bigthumb:
 
jas67 said:
As my EV-converted Vespa will have 70AH (72V/20S) of battery capacity, I'd like to get a higher-current charger (currently have a 4A and an 8A, which I've used in parallel for 12A).
If you're willing to spend the money on them, Meanwell HLG LED PSUs have been used successfully in series and parallel as chargers. They are solid potted and fanless, so can also be mounted to a vehicle, and won't die when a fan fails or becomes dust-clogged.

For your system, two HLG-600H-54A in parallel, and then seriesing I think two HLG-480H-36A in parallel, should give you up to 20-24A at up to 84v, once adjusted for voltage and current. Since they are separate units you can either plug them into separate outlets/breaker-circuits on your panel to limit 115VAC wall current, or you can use them on 230VAC instead and wire them all to one AC plug.

Not small or light, but durable and reliable.

The only catch is they are not chargers, so they will not automaticlaly shut off at end of charge. For that your BMS would need to disconnect fully, or you would need to add a disconnect circuit (timer, current monitor, etc), of which several types have been posted over the years (sorry I don't have any links). For my setup on the SB Cruiser trike, I just remember to unplug it when I know it will be done.
 
batteryGOLD said:
How many Km's(miles to Km racio 1,61) U drive every day??

It varies a lot, but, if I ride to my job about 40 miles (64km). I often go out to lunch when in the office, so, that could add another 10 miles.

My range on the 38ah battery is about 35 miles given the speeds I typically ride (not an urban environment, but, one requiring 45-50 MPH). So, I'm looking to get about 55-60 miles total range with the second battery in place.

55-60 miles is about right for the 5 kwh I'll have. The Zero motorcycles typically get about 120 miles from their 14.4 kwh battery.


batteryGOLD said:
the other option 25A will overload any AC socket :lowbatt:

The 25A one has 240V input, so, doesn't plug into a regular US socket, but, at 240V one.
 
Regarding charging to 80%, I just program the BMSs to turn off charging at 82V instead of 84V.
 
I use three meanwells 24v turned up to 28v each for 84v @ 15amp. They must all be adjusted to the same voltage before use and will not shut completely off so . Maybe a timer ?
 
Here's my three meanwhile chargers I also put a split in there so I can charge at 56 volts with the middle ones as 4mm. Two chargers in one. Oh oh stupid me it's also 28 volt so three in one with jumpers. Jumpers are Hot when running.
Be careful.IMG_20230206_145304914.jpgIMG_20230206_145312038.jpg
 
Probably garbage. The only ones I’ve had good luck with are these ones which are modded Huawei r4875 power supplies. Do 72v 50a all day. Two of em in parallel will max out a single J1772.

US $209.00 5% Off | 50-120V 0-50A smart fast charger 30A 45A 50A adjustable charger for 12V 24V 48V 60V 72V Li ion Lifepo4 LTO lithium battery
https://a.aliexpress.com/_mM4mFdY
 
I bought this one from China on PayPal it wouldn't even light up I found out the burnout part try to replace as they asked me to try to replace it and it wouldn't work plus because of PayPal they had to give my money back.
84v10amp. backIMG_20230207_175606869.jpg
 
999zip999 said:
my three nice meanwhile POWER SUPPLIES to charge a 84V 20S battery.. *edited

Hi Sir, very nice power supplies! butt.. U're doing a very dangerous setup!! Did U just did that?? :warn:

There is a difference between a POWER SUPPLY and a CHARGER
power supply is constant voltage CV it supply a fixed voltage up to rated Amperes vs a charger is a constant current source CC up to rated current limit , but varies output volts to match battery charge curve.

U've done serial x3 power supplies equals to one great power supply locked@84V up 14A current draw.
everything fine, until you connect to a 20S battery.. The safety just depends on difference volts between power supply constant voltage and battery voltage! Is it just a time bomb?

Lets say a 84V 20S battery has internal IR 100mOhm, and power supply is a very low IR source, so maybe x3 series power supplies have an IR of 10mOhms

15A=(84V- Vbattery)/0,1 --> Vbattery equals 82,5V (this is minimum battery voltage to get max 15A) if battery is under 82,5V so the system will try to output more than 15A (this will overload all x3 power supplies). A danger range situation :warn:

soo if U connect a battery from 82,5V(90%SOC battery) to 84V(100% SOC) interval, Ure "charger setup" is fine up to 15A!
but lets say U connect a 50% SOC battery, this maybe @ around 72V
soo ohms law --> I=U/R --> (84V-72V)/0,1 equals 120Amps chargin draw :flame: at this time U're x3 serial meanwhile power supplies are trying to output 120A..(but power supply rated limit is 15A)

maybe U're lucky if power supply enables short circuit protection or overheat protection,
if not U're running a very dangerous "time bomb setup" --> just continue at YOUR own risk!

and the worst case, if you have x3 power supplies serial, then each have different voltage shutdown. soo if one of three power supplies enables cut, the other two continue to supply power. means only 2 of 3 supplies vs a 84V battery.. this means reverse current from battery to chargers.. it could be a very mess.. (unless power supplies have reverse protection, butt 99% power supplies does not have reverse current protection)

NEVER USE POWER SUPPLY to charge any battery! STOP :bolt: :bolt:
 
there is a thread somewhere in E.S. on how to setup and use these models and set them up in series. Just like I have and been using on 24s lifepo4 A123 20ah no BMS and my Samsung 40t 20s 6p with BT BMS the one with the elephant. I have been doing this for 5 years and no problems yet . Work great. Will recalibrate before use as they need to be set all the same voltage.
would now like to hear from others about my setup and your response to it. 5 years.
Thank you for your concern.
 
999zip999 said:
there is a thread somewhere in E.S. on how to setup and use these models and set them up in series. Just like I have and been using on 24s lifepo4 A123 20ah no BMS and my Samsung 40t 20s 6p with BT BMS the one with the elephant. I have been doing this for 5 years and no problems yet . Work great. Will recalibrate before use as they need to be set all the same voltage.
would now like to hear from others about my setup and your response to it. 5 years.
Thank you for your concern.

Sir, do U trust any posts on tha web? I assume U know basic electronics :bolt: :bolt:

U're very luck for a 5yr period, so maybe setup is safe.
But according to electronic rules, that is a crazy setup. or maybe me just crazy :D

or maybe your meanwhile power supplies has miracle protection of converting from CV to CC after 15A limit reach.. this is purely lucky!! otherwise is unknown whats happening behind tha scenes.. :pancake:
 
999zip999 said:
original thread is deleted.
safely on ES ????

Sir, just buy a 84V charger 10A or 15A from aliexpress or ebay to replace your system setup..
But If U want to save cash.. keep using your system.. Its up to you. I did explained why not!

It's just my advice.. but I'm just crazy :twisted:
 
I just don't get it I've read and was told I could put three mean Wells together of equal voltage. I think A.W and LFP if I can remember right. And guy in Washington State sold them 2or 3 at a time just for series charging and yes . They are isolated and they are C.V C.C . Medical grade. Or that's what I'm smoking.
I hope somebody else is reading this and can chime in so I go to bed at night.
What another crazy on the internet who would think.
As you saw I did buy an 84 bolt 10 amp charger from AliExpress it popped when I plugged it in what a waste of time a lucky I paid by PayPal and got my money back they did want me to try and repair it myself. No just send me my money back.
I would send you the 84 volt 10 amp charger from AliExpress but it cost too much to send to Portugal if that's where you're at at the moment[ATTACH type="full" alt="IMG_20230210_173728226.jpg[/attachment.
If you want to pay for shipping I will ship it to your address
Hey I just looked at it you're in luck it has a 10amp and 5 amp switch

[attachment=0]IMG_20230210_173940616.jpg"]0[/ATTACH]
 

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I received the 15A charger. It works, the high/low switch works (15A/7.5A), but, the LED display, and the green/red LED status LED do not work. I'm trying to decide if it worth dealing with the return, or if I'll just keep it.

EDIT: I'm returning it, just in case something else in it wants to fail later.
 
batteryGOLD said:
NEVER USE POWER SUPPLY to charge any battery! STOP :bolt: :bolt:

Nonsense. Power supplies like MeanWell work great to charge our batteries as long as you observe two principles:

Don't max out your permissible charging rate for the cells, and

Don't charge to the maximum per-cell voltage.

I charge my 12S packs with MeanWells exclusively, and I've done so for years. But I charge to 4.05V/cell, and I charge at less than 6A even though all my packs can take a much higher rate than that.

The only possible concern I see with using a PS to charge is if you go screaming right up to 4.2V per cell at a high constant charging current (relative to the cells' rating).
 
Thanks Chalo as I'm always scared of fire. A W. also said it's ok if setup correctly.
I guess batterygold is right he is crazy as he has said about himself. I guess if someone wants to scream out they're crazy you got to believe them.
 
The meanwell HRP have CC and CV.
So no need to worry about that.

The only thing to worry is when one supply dies, then the others see probably a higher voltage than they can handle.
At least you have to have a fuse in the charging wires to prevent the supply to catch fire. When something goes wrong the battery has a very high short circuit current which can burn Dioden and mosfets easily.
 
Donimik As in my picture where would you put a fuse ?
How many amp fuse and how many ?
Charging 20s 6p @ 15amp on a 120v household circuit.

[attachment=0]IMG_20230206_145312038.jpg[/attachment
Or can I put one on the neg side so] I could run 28v, 56v and 84v
 

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