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-   -   >5 year old Lipos (https://www.rctech.net/forum/radio-electronics/1069046-5-year-old-lipos.html)

Wyumez 07-11-2020 04:56 PM

>5 year old Lipos
 
I opened a box of my old RC stuff that was stored in a shed in Florida for a few years. That includes five 2s lipos, and rtr trucks.


Two trucks have both HOBBYWING EZRUN 3656 4000KV RC Brushless Motor & WP SC8 120A ESC Combo ME178


Anyway, I am only able to run a full charge battery (8.4v) for about five minutes until it starts slowing down and ultimately stops running. I looked at the ESC and it's blinking red. The ESC doesn't feel hot, and the motor doesn't feel too hot. I then turn the truck off/on and I'm able to run the trucks for a few more seconds until it stops again.


I think the lipos went bad because they weren't in the "storage" setting before I boxed them up, but do not want to purchase more batteries if this is the case. The three of my five lipos are swollen, so I won't be using those anymore, but the two unswollen lipos both have the same issue on both trucks.


Per the ESC manual, if the car is running then slows down and stops, it's the LVC protection, but when I put the battery on the Venom Pro Charger, it shows >7v remaining. Any help would be greatly appreciated. Thank you!

Ominex 07-11-2020 05:26 PM

Just cause a LiPo isn't swollen doesn't mean its good. Even put in storage mode they start to degrade. They lose their ability to hold a charge as you are seeing now. If your charger shows IR then see what they are at. A good battery should be between 1-5ohms. Anything above 20 should be retired. At 30 or higher you run the risk of fire. If it is a standard 2s 5000(ish)mah with about 5 min of runtime I would imagine the IR is quite high. Run at your own risk. Personally a 20-30 cheap battery is worth it if I dont end up burning down a house or the car its in.

Also a lipo is low (should not be run lower then) at 3.2 a cell so for a 2s battery its 6.4. Your ESC could have the cutoff set at 3.5V per cell or 7V. Another contributing factor is that since they are so degraded that the voltage drop during use hits the LVC but when there is no load it jumps back up a bit. This effect would be worse with a older battery.

billdelong 07-12-2020 09:37 AM

+1
All batteries age and generally should be replaced within 1-2 years regardless of how much use they had.

There are many factors which effect the life of a battery with heat being the biggest factor, so if they were stored outside in a hot shed in summer, then they were probably gone after that summer.

If your charger doesn't have an IR meter, then I would make that your next investment where IR will give you the overall health of your cells:

Alexv2024 07-13-2020 12:36 PM

A shed in florida? So they got hot often and weren't at storage voltage the whole time? They are all junk most likely.

What was the voltage when you first charged them? Also if you stored them at 4.1 to 4.2v a cell that even for a few days degrades the cell capacity, just as going below 3v will.

My friend only runs about once a week, and he stores his lipos in a fridge. His 1 and 2 year old lipos have great internal resistance. A shed in florida is literally the polar opposite and for far longer. Thats the worst case scenario for batteries.


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