Fromeco Battery Charging Requirements

Fromecos' Relion Lithium Ion battery Charger Requirements


  1. *LITHIUM POLYMER Setting*  DO NOT use the Lithium Ion setting if the charger has it.   If you use the Lithium Ion setting on a charger for our batteries the batteries will not be fully charged.   Yes the batteries are Lithium Ion, but the Lithium Ion setting inside of chargers is designed for 7.2VDC battery packs, ours are 7.4VDC just like a Lithium Polymer.
  2. 7.4VDC nominal (Lithium Polymer charge setting)  8.4VDC will be observed when fully charged.
  3. 2Cell for both the 2600mAh and the 5200mAh.   The 5200mAh pack does physically have 4 cells, however it is still charged as a 2 Cell.
  4. Charge Rate-  2.6Amps for 2600mAh battery pack,  5.2Amps for 5200mAh (connector limiting, JR connectors CAN NOT handle 5.2Amps.) 


  • Hello Paolo,
    Thank you for the excellent question. It is one that gets asked frequently.

    1. Paralleled batteries tend to self balance. Think of a hose plugged at both ends filled with water half way. Now bend the tube in a “U” shape, the water will equalize with equal amounts on both sides of the “U”. This is just an analogy used get ones gray matter around “P”, not a scientific explanation.
    2. Serial batteries do NOT tend to want to balance when they become out of balance. Some form of force or engineering must be used to bring them into balance.

    The direct answer is NO, there is no balance Circuit in our packs, when we sold the A123 cells we did make a package that had a balance circuit that was built into the pack. A123’s require some form of balancing due to the their manufacturing profile, which is not very good.
    The cells Fromeco uses for the Relion packs come very closely matched from the Factory, their respective impedance cell to cell is very close. Single cell impedance is the key to either needing balancing on assembly or not. When you have cells that have large impedance swings from one cell to another upon manufacturing, balancing is a requirement.
    This is why we do not sell our packs with balance boards or balance plugs (NOTE: if you ask for we can install it, “a plug”). The only real reasons to balance a Relion is for charging purposes, there are chargers out there that require a balance plug to charge. For that reason we can install plugs if desired. However that takes a call to Fromeco on the order to initiate.

    If all of the above is true why do polymers even high quality ones have a balance plug? Well that is a different reason, it has to do with the fact that Polymer batteries are almost exclusively used as a Gas Tank for an electric motor, there are heat dynamics coupled with the layering of the individual cells that cause the individual cells to discharge at different rates inducing an imbalance.

    Kurt Cook
  • Excellent knowledge base. Now a questione, does the larger 5200mah Relion come with its own balancing circuit inside? I am guessing it is required since it is setup as a 2S2P battery. Thanks.

    Paolo De Berardinis

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