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Fold X battery diagram or info on which connections are positive or negative

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Hello, I have a dead battery that I'd like to jump a little to get it to charge. I have done this using a solar panel with direct 12v current to bring a dead battery up a little so the charger will recognize it. I am just wondering about which of the inserts where the fins go into are positive and negative. Thank you!

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Use a Digital VOM or Volt Ohmmeter , this will indicate which pins are POS/ negative contacts. The second issue is 12 volts won't be enough to even trickle a charge into it. It's likely a 48volt/ 14ah battery which charges from a 54 volt charger.

Also IF the battery has been Drained for a Long period of time, you May not be able to bring it back up again.

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@Jimbo James   There are two procedures you can check, before you replace the battery, especially since you say it went bad so quickly. Open the case and make sure it’s not the switch or a bad switch lead connection, especially since it only measures 4 V. Check the connections to the charging port and wires to the power supply lines and battery terminals, to the controller inside the battery case. We have had a switch with a poor connection discovered before on the forum. They can leak voltage. 
Lastly you can try bypassing the BMS inside the case with a non-Li Ion charger (if all other inspections fail) because the charger you have, also has a BMS with low voltage cut off that keeps it from charging. Out of curiosity have you checked your chargers output voltage?

I have two 36V Batteries from the 1st and 2nd Gen Sondors Fat’s, that have not been used in 5 years. Because of your post, I went out to my studio, where I keep them stored and they are both over 40V, which may have been the voltage when I replaced and stored them, upgrading to 52V batteries (recommendations are to store batteries long term @ 50% capacity). One of them I had removed the fuse to send to a member in Florida just after a Hurricane there because his was blown but I forgot that when I initially measured the voltage and that battery measures a minimal voltage (1.4 V) without the fuse. ¿ I’ve yet to figure that out. Maybe a low voltage signal leak.

The fact that your battery, only shows 4V, (on or off) means something is wrong with the batteries internals or electrical system (even if the battery switch was left on). I’m hoping you can measure appreciable voltage inside the case, if so with no obvious broken wires, I’d suspect the batteries BMS as a possible cause.  My bikes & Matt Robertson’s, show no voltage drop from batteries that are left connected to the controler, we have no switch. I do unplug the connectors and let the battery pack cool, if hot, before I connect the charger. LCD’s Time-Out.  
I wouldn’t give up yet. Go deeper. 




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Yay! Conclusion and result: I open up the battery and disconnected then reconnected the only wire that had a connector. I started measuring voltage on the board and was getting results in the 30-40v range. Tested at the output fins and read 50v. Put it all back together and it's now on the charger successfully charging! I'm thinking either 2 things: the small connector for the on/off switch became dislodged or there may have been a static buildup on the board that needed to be discharged. Going to take it for a spin after it fully charges to see if these might be some type of loose connection still, otherwise I  hope it's fixed! Thanks for your help Ian and Reddy! 

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