Trickle charger not maintaining charge

[dee0007]

I have a bmw trickle charger not maintaining charge on new battery recently replaced and i have registered it. It seems to me that the trickle charger is not maintaining the charge since i have the battery light come up after starting my car yesterday. I had this problem every winter since i was storing my car. I thought it was the battery issue and now Im starting to think its something else? how can i diagnose to determine what the issue is? is there a certain way to connect it? i have it connected at the front not directly to the battery. But can that really by the culprit?

[BMWCCA1]

BMW chargers are notoriously unreliable. The "original" made by Deltran often fails and can't seem to take the slightest electrical interruption from power surges. The C-Tek versions seem to work better but also fail. Not sure whose they're using now but you may want to check the charger. I've even had BMW chargers fail to the extent that they would discharge the battery while connected.

[dee0007]

Good to know , thanks. Could you suggest a good one ? Do I get a 800 or 1000ma?