Renogy DCC50S very low charge from Alternator

The Renogy DCC50S is potentially a great product with a high charge rate from both vehicle and solar and good protection features and all at a very reasonable price - if only it worked properly from the vehicle alternator! This thing is great on Solar but its a bit problematic as far as car charging and not as good as it could be. Dont get me wrong its a good quality unit but should be so much better on alternator charging. Watch this and I show its short comings.
Good general technical appraisal of this product from Will Prowse at DIY Solar Power:
https://www.youtube.com/watch?v=JtAUrS4zNSA&t=19s
Renogy DC/DC Charger information can be found here:

https://www.renogy.com/dcc50s-12v-50a-dc-dc-on-board-battery-charger-with-mppt
Purchased from Amazon but you can buy direct:
https://www.renogy.com/dcc50s-12v-50a-dc-dc-on-board-battery-charger-with-mppt

Видео Renogy DCC50S very low charge from Alternator канала Tim Terry