Paralleling Power Supply Units Made Easy ???
I am considering paralleling a couple of 20a variable adjustable psu's for 40a charging. According to what I have read on the world wide inter-web, it can be done quite easily, provided the following ...
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You need to disconnect the solar panel before removing the battery because the solar sensing circuit (op-amp or whatever) has no power when battery is removed. This sensing circuit is now vulnerable to over current from the solar panel.
BTW, I see no scenario where the power supply is damaged when removing it under power from the battery. When in CV mode, the PS voltage will remain at the exact voltage level when it's unloaded. The voltage doesn't change whether it's loaded or unloaded.
BTW, I see no scenario where the power supply is damaged when removing it under power from the battery. When in CV mode, the PS voltage will remain at the exact voltage level when it's unloaded. The voltage doesn't change whether it's loaded or unloaded.
BFL13 wrote:ken white wrote:jrnymn7 wrote:
If I understand Salvo's recent posts, deliberately engineering in some extra voltage drop would be very helpful.
From my original post in this thread:
"The idea is to parallel them by first connecting the + and - leads from both psu's together, to a single + and - lead, which is, in turn, connected to the load/batts. The belief is the voltage drop over the leads will compensate for any minor fluctuations in voltage output of the two psu's. This will, allegedly eliminate the need for a more sophisticated arrangement, including diodes and such."
Note, this may only apply to units with adjustable cv and cc settings.
If you are operating the power supply in a constant current mode for charging, and the batteries are connected, you will be fine.
If you disconnect the batteries while in this mode, the voltage will assume some unknown state depending on load current demand and you will probably damage some electronics.
Just an FYI...
That reminds me of the warning with some (all?) solar controllers to never have them connected to the array without being connected to the battery or you could damage the controller.
Always connect battery first, disconnect battery last. Important when you have solar and are swapping batteries around, when you could have a time there with no battery and the array still connected. I have a switch in my array to controller wiring to easily turn off the array before disconnecting the batteries for that reason.
