Unless I misunderstand, that's an unfair slur on the Zappi I think. It has much more than a basic timer and is otherwise very configurable. For example, whilst I don't have a battery, I don't want my MG4 charging during the day as that would cost me £0.42 / kwh (effectively the equivalent of your battery), so I have the Zappi set to charge 00:30 - 04:30 and can leave it plugged in for days without it taking peak charge. So I'd say the Zappi is not a battery thief if setup reasonably.
Sorry all this is a little off topic.
@nbenn I'm sure many of us here could help you over your problem, do ask