. Would a faulty charger have "fried" my batteries irreparably?

 

 

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yes

Yes x2. And ask away brother! That's what forums are for. It's good to learn how your systems work and to be able to diag and fix things yourself. None of us popped out knowing how to test an on-board charger.

Would a faulty charger have "fried" my batteries irreparably?

 

Yep it certainly could. It's worth a quick test just to make sure it's working properly otherwise you'll end up having to pull the batteries out again when the next one goes bad.

 

Ask as many questions as you want, that's what the forums are here for!