Not good. I would not trust it.
That 25A is maximum, and they will not be happy running at 25A for long.
May be able to squeak by a bench test using 3, instead of 2.
The 50V is low.
I like metal bridges.
The photo is taken from the heat sink side. The other side has 4 terminals like are usually shown.
Our hosts have 35A 200V bridges.
I would use 3 bridges if you expect to go past 25A, or up to 35A.
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The alternator has 3 wires. With 3 bridges...
Each alternator wire goes to its own bridge, and connects to both bridge AC (~) terminals.
The bridge + goes to the battery +.
The bridge - goes to the battery negative.
The positive terminal is often turned 90 degrees from the others (like Dan's bridge photo), or has a corner angled (RatShak photo), and is usually marked +.
The AC terminals are next to the + terminal, and are often marked AC or ~.
The negative terminal is opposite from the positive terminal.
They need serious heat sinks, and heat sink compound.
G-