I'm currently working on a project where I need to design a device to power a 24 V, 350 W motor using 18 V tool batteries. The 18 V output from a single battery is sufficient in terms of voltage, but unfortunately, it doesn't provide enough current to power the motor. Therefore, I'm considering using two 18V batteries in parallel to meet the current requirements.
The challenge I'm facing is how to safely parallel these batteries without running into issues like one battery discharging into the other. I've considered a few options:
Diodes: Adding diodes to each battery line could work, but this approach generates a lot of heat and would require large heatsinks, which is not ideal and one battery takes the load if the voltage is different between them.
Ideal diodes: These create an OR-ing condition. Some have a sharing condition if the voltages are close enough.
Powermuxes: Just a switching mechanism between sources.
I've also thought about more complex and potentially expensive solutions like using two stackable boost converters. Another idea was to connect a buck/boost converter to one battery, with a load sharing IC that could sense the other battery and match its output. However, these options seem overly complicated for what I'm trying to achieve.
I would greatly appreciate any insights or suggestions on how to tackle this problem effectively. Are there any simpler or more efficient methods to safely parallel two 18 V batteries for my application?
Thank you in advance for your valuable input!