Someone is selling a used 60V 45 Ah factory Lithium battery for my moped. I am considering it but won't be able to test it on my moped. He sent me a video probing the output with a DVM and it read 67.2V (with no load). I have a 1400 watt heater coil from a drier or dishwasher with a resistance of 14 ohms. That works out to 4.7 A per ohms law across 67V. I'll have a clamp on ammeter and DVM to monitor amps drawn and voltage. For a good battery, what should I see for a voltage dip with a 4.7 amp load?
Considering buying a used 60V 45 Ah Lithium battery. How to test standalone?
- Thread starter Zambam
- Start date
Chalo
100 TW
That's only 0.1P. Probably a weak tired battery wouldn't have significantly more sag than a strong battery at such low current.
If it's actually rated for 45 Ah. 4.7A load would only be about 1/10C. And for me, a high-discharge moped battery really shouldn't be dipping much at all at 1/10C. Can you leave the load for 10-30 minutes to get at least an estimate of capacity?
That'd be about 0.8C. I'd want to it sag less than 5%.
What would be more helpful is cell info. Could you get that info, and then we could look up a discharge curve for the cell to see what is expected?
I would not be able to get cell info before trying the battery. I intend to take the metal cover off to make sure it has not been tampered with before buying and can get cell info then if visible. It's a factory battery made specifically for my moped and probably use Samsung or LG cells.
Well, it was a total waste of time. Yesterday, I got a video from the seller showing DVM reading of 67 V when connected to the battery = full charge for a 60V Lithium. Seller brought the battery today (we met at a local shopping center). First thing I did was measure the voltage and it was 60 V! Either it's a different battery or it self discharged 7 V overnight. Told him I'm not interested.
