I have a weak autogate battery, can I use Bosch C7 charger to charge it back?

I think you can (I havent tried it personally!)

But I dont think it brings any benefit, since the battery for autogate is dynamically connected, means the current is passing thru the battery, hence its charged at all times.

Unlike our car battery, its static, where it only charges when alternator is moving.

If 12V, can. I have the same charger too. Used it to charge my UPS battery. Same type used for alarm and automate.

Anyhow, if still weak, better replace it. A new battery only 30 bucks on Lazada.

Remove the battery from the gate, and it can be charged with the Bosch charger. The Bosch charger is compatible for charging and maintaining Sealed Lead Acid batteries.

U can.

But if the current is too low, it might not trigger charging action from the charger itself.

Yeah, it can't. Just tried it.
I think i will not place a new battery to my autogate for now.
If no electricity, then I just manually unlock it.

Plus, my area seldom have no electricity...

Just use laptop charger to re-charge the autogate battery and it works!
But before that, I added some distill water into it before charging. Lost of hissing sound when charging then after 8 hours, it's fully charged at 14.20V!