PTO Winch Advice Needed

A bit dirty, been kicking around for at least 9 years.

https://www.sterling-power-usa.com/Ster ... arger.aspx
At $150 it would be cheaper than an alternator and all the stuff needed to make it work. 50 amp charge is only 25 amps below the max of the 25 SI and much simpler.

Sweet! I'll be studying it closely and probably be asking more questions about it here and asking the Sterling Company tech support person questions too. It just seems too simple. Do I understand it can charge a second deep cycle battery isolated from the main vehicle start and run battery system? And with no modifications to the original alternator /regulator? Or do I have it all wrong? It's 2am so time for me to forget about it now and go to bed.
Thank you, thank you!

Yes, it does, and it multi-stage charges the aux while the alt and starter battery is charged like a normal car. The are on sale because many are now going to Lithium batteries ($$$$$) that this model can't charge (shouldn't be used to charge) so they are selling off stock cheaply.
It is similar tech to what is used on hybrid and EV cars to charge the aux battery in them. It just used to be too expensive for me to consider, so I didn't even look into it when we were discussing the alternator mods.