This other thread where we are discussing finding a safe way to charge multiple Li-Ion batteries is getting pretty long. This topic is to give a NEWBIE's pictoral guide to modding the Voltcraft cradle in the hopes that we can get more of them from a group buy.
When combined with a safe 4-channel parallel charger like the DN/Tenergy which comes with an AC, 5A power supply in a package deal like this, it gives a great way to safely charge Li-Ion cells without the fire/explosion risk that is associated with universal $20 chargers that do not detect unbalanced high voltage cells that develop in a battery pack.
The only other safe alternative is the 1 or 2 cell Pila or Ultrafire chargers that "balance" cells by individually charging them all up to the same 4.2V...but these have very low 0.6A per cell charge rates....so it takes a long time.
After an exhaustive search, we realized that noone has ever made a universal cradle to hold Li-Ion rechargeable cells, and while it would be relatively easy to manufacture (and at least one RC dealer is considering having them made), the only stop-gap measure is to use a simple DN/Tenergy 4 slot charger (or Cellpro 4S) with a German made Voltcraft universal 4 slot cradle for NiMH/NiCd cells.
Because Li-Ions are different sizes, this Voltcraft cradle must be modded. It can be done VERY easily if only used with this DN/Tenergy maximum 2A per slot output charger, and labeled pictures in this post make it clear how to do that. After the last picture, just reattach the spring, solder back the black wire and reassemble.
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The next post assumes you wish to upgrade the 22gauge existing wiring for higher Amp charging, and to also use separate balancing taps for a more robust charging method. This chart shows the limitation of various wire gauges as it relates to charging Amps applied for a given voltage. With the output limit of 2A per cell (or 6A for all 4 cell slots combined) from the DN/Tenergy charger, the 22gauge wiring is still safe. In this lower current Tenergy scenario, you actually charge through the "balancing tap" connections to each cell, via 5 banana jacks as shown below.
The advanced chargers normally deliver their higher power current to the single POS/NEG battery pack terminals ONLY, and do optional per cell balancing with the low current smaller "Tap Lead" wires.
With more advanced chargers such as the Schultze, Triton2, or Hyperion 1210i, etc. you can charge at higher rates, and daisy chain the 4 slot cradles to allow 4, 8, or 12 safe Li-Ion cell charging in series with taps to balance the voltages. These more advanced chargers require larger wire to safely transfer higher Amp current flow, and also need larger 12Volt power supplies than the Tenergy setup.
When combined with a safe 4-channel parallel charger like the DN/Tenergy which comes with an AC, 5A power supply in a package deal like this, it gives a great way to safely charge Li-Ion cells without the fire/explosion risk that is associated with universal $20 chargers that do not detect unbalanced high voltage cells that develop in a battery pack.
The only other safe alternative is the 1 or 2 cell Pila or Ultrafire chargers that "balance" cells by individually charging them all up to the same 4.2V...but these have very low 0.6A per cell charge rates....so it takes a long time.
After an exhaustive search, we realized that noone has ever made a universal cradle to hold Li-Ion rechargeable cells, and while it would be relatively easy to manufacture (and at least one RC dealer is considering having them made), the only stop-gap measure is to use a simple DN/Tenergy 4 slot charger (or Cellpro 4S) with a German made Voltcraft universal 4 slot cradle for NiMH/NiCd cells.
Because Li-Ions are different sizes, this Voltcraft cradle must be modded. It can be done VERY easily if only used with this DN/Tenergy maximum 2A per slot output charger, and labeled pictures in this post make it clear how to do that. After the last picture, just reattach the spring, solder back the black wire and reassemble.
-------------------------------------------------------------------
The next post assumes you wish to upgrade the 22gauge existing wiring for higher Amp charging, and to also use separate balancing taps for a more robust charging method. This chart shows the limitation of various wire gauges as it relates to charging Amps applied for a given voltage. With the output limit of 2A per cell (or 6A for all 4 cell slots combined) from the DN/Tenergy charger, the 22gauge wiring is still safe. In this lower current Tenergy scenario, you actually charge through the "balancing tap" connections to each cell, via 5 banana jacks as shown below.
The advanced chargers normally deliver their higher power current to the single POS/NEG battery pack terminals ONLY, and do optional per cell balancing with the low current smaller "Tap Lead" wires.
With more advanced chargers such as the Schultze, Triton2, or Hyperion 1210i, etc. you can charge at higher rates, and daisy chain the 4 slot cradles to allow 4, 8, or 12 safe Li-Ion cell charging in series with taps to balance the voltages. These more advanced chargers require larger wire to safely transfer higher Amp current flow, and also need larger 12Volt power supplies than the Tenergy setup.
