Having a problem with cheap lithium battery pack in my portable solar setup

[Loneeagler]

Hi, I could use some help if possible. I am having some problems with a battery I just got and finding it hard to find an answer anywhere as to if it's working right or not. (SUVIJIA 24V 58000mah Lithium Battery Pack) used in e-bikes, scooters etc.
These batteries are sold as 24V but say 29.4V on the battery. It's supplied charger (25.2V 2A) is charging the battery up to 29.6v is what the multimeter reads on the battery after it's charged. I think this might be too high for this battery I'm not sure. What it's doing is discharging very fast from 29.6V down to 23V within 15 to 25 minutes only charging a Bluetti EB3A Power Station battery a (12AH battery) directly plugged into it only getting about 50% of it full. I know these type batteries are over rated as to the actual AH but this is the only one that I'm having trouble like this with. I've discharged and recharge it 4x now with no change in it.
I'm still waiting on the sellers response . It being from China I doubt that It will be replaced. I would just like to tell them experts have told me that it's bad. Maybe it might help.
What I'm wanting to use this battery for is mainly to charge other batteries in a portable solar charging setup I have for when I go camping.The solar panel is 52V for the 52V e-bike so I can't use it with anything but a 52V battery. So I plug the 52V solar panel to a 52v battery then into a solar charger controller into a 12v or 24v battery to charge my Bluetti EB3A power station (DC IN 12-28VDC 8.5A Max) a 24v battery will charge it faster than 12v is what I'm wanting out of it.
I hope you can give some insight to my problem thanks.

SUVIJIA 24V 58000m4h Lithium Battery

25.2V 2A Battery Pack 18650 (14)6S3P)<(Not sure this is right) 58000mAh 24V Rechargeable Li-ion + 25.2V2A Charger

Product parameters
Capacity: 58000mah built-in BMS

1: Requires a lithium-ion battery charger; constant current, constant voltage;
2: Charging voltage: 25.2V
3: Charging current: below 2A
Battery discharge requirements:
1: Rated discharge current: below 10A
2: Maximum instantaneous current: 60A
3: Maximum working current: 45A
1 plug XT60 DC built-in BMS*1

 

[TacomaJoe]

I think there may be a charger issue. If you have the set shown in your attachment, that is a 25.2V charger and a 29.4V battery. The cells are 4.2V, six in series is 25.2V, seven in series is 29.4V. You may be able to verify the series total by counting the cells in the battery. Does it have 14 (7S2P) or 18 (6S3P). A 25.2V charger is not going to fully charge a 29.4V battery.

 

[TacomaJoe]

I count 14 cells, so to me it looks like a 7S2P battery needing a 29.4V charger.

 

[Tomthumb62]

I know these type batteries are over rated as to the actual AH

This is very likely your problem. Fake and grossly over rated batteries are super common in especially the 18650 and similar size cell world. I would never buy such battery from eBay, Amazon, Aliexpress or other similar online marketplaces.

You can often tell it’s fake by the price. If a genuine retailer sells it for $75 and you paid $20 to an anonymous online marketplace, then you took the bait. Buy only from vetted and respected websites that specialize in these kinds of batteries and charge a reasonable price. If it’s ultra cheap, look no further.

 

[MisterSandals]

25.2V2A Charger

Have you measured the voltage with a meter?

 

[Loneeagler]

Hi, The charger on reads 30.4V on the output connector with multimeter. it's charging the battery up to 29.6v. I know these are crappy batteries and chargers but I'm on disability and very limited income to buy the better option. Just trying to get by on the skinny. The battery itself is really just to get the 24V I need to charge the Power Station faster. I have a 12V 50AH lifepo4 battery also to charge it with but only @ 99W. If the 24v battery allows me to charge safely I can get by with it for now. I'm thinking it's the Nominal voltage of 29.2V with this battery that's the problem, It needs to be less V for that charger and my power Station under 28V. I'm just wondering if it is a bad BMS or just junk because of the fast voltage drop it does and low capacity. maybe I can get a refund or exchange for it.
Any recommendations on an inexpensive 24V 50AH battery?

Seems like everything I buy today is from the biggest environmental and junk products polluter of the world
Here is a Amazon SOKERDY 24V LiFePO4 Battery, 25.6V 46Ah battery I was looking at I doubt if they are any better.

Amazon.com

Thanks for you help. Greatly appreciated. Happy Holidays

 

[MisterSandals]

I reread from the top and found something:

The solar panel is 52V for the 52V e-bike so I can't use it with anything but a 52V battery.

This is not true. MPPT SCCs are designed to take high voltage and charge lower voltage batteries. A 250V array can charge a 12V battery just fine with the right SCC.

I don't see any mention of a charge controller in this thread. Are you interested in charging with solar using your 52V panel? If so, quite a few SCCs can be setup with a custom battery profile to charge your 7S2P battery (is this really just a mid-voltage storage device so you can eventually charge your Bluetti?

This has gone off into the weeds of unnecessary complexity, possibly because of your misunderstanding of MPPT SCCs. There might be a solution to go fro 52V panel with an SCC (or other device?) right to the Bluetti.

 

[Loneeagler]

At one time I tried to connect the QuietKat Portable 52V solar panel directly to the Victron Smart Solar MPPT 100V/15A controller with and without a12v battery to Bluetti and it would not connect., The panel only worked when connected to a 52V BMS battery. So I just assumed these things look for a battery with a BMS before they will connect and start charging. The setup I'm using works with a 12v battery into the Bluetti. and I am charging 2 batteries and Bluetti at once. (See Chart) So when there is no sun I still have the 52V 48AH and the 12V 30AH batteries to charge the Bluetti with the setup. When primitive camping for a week every other day 4+ hrs. charging ebike and batteries wastes a lot of my time when I can be doing other activities. So I was just wanting to speed things up with the Bluetti using a 24v battery cheaply. I tried a 12V to 24V booster converter it worked and flaked out the Bluetti after a min. and went back to slower 12v charging. I'm open to suggestions. I'm new to batteries and solar and still learning. Thank You.

 

[TacomaJoe]

Your 29.4V battery exceeds the Bluetti input voltage range (28V). The SOKERDY at 25.6V would be fine.

Is the bottom line, keeping the Bluetti charged? When the sun drops you will continue charging the Bluetti by stealing power from the bike battery.

 

[Supervstech]

You do understand that the battery you have is a 4 or 5 Ah 25.9V battery...

The specs math out as 4.2Ah per cell... i do NOT believe that... more likely around 2 to 3 Ah per cell, x 14 is your actual rated mAh spec, likely around 42,000 mAh
So a max of 6Ah at 25.6V rated voltage. Max charging of 29.6V



So... it haa a total Wh capacity of 153Wh...
You arent going to charge much with it is what im saying.

 

[Supervstech]

I would get a 24V lifepo4 25Ah or so, and have MUCH more Wh available.

 

[Supervstech]

The big issue with your little battery pack is it can VERY easily explode...