Tamz left this testimonial on Facebook of how he managed to recover his solar batteries that were no longer able to accept a charge. In the image you would note how he has hooked up the 24V Infinitum Desulfator in parallel with two 12V batteries that are hooked up to make up 24V.
The testimonial is a mix of Filipino and English. Below is the translation:
DOUBLE YOUR BATTERY LIFESPAN