Yeti Link not - actually - float charging AGM battery?

Solarnator
Solarnator Member Posts: 2 ✭✭
in YETI PORTABLE POWER STATIONS

Sooo not so quick question: got the Link expansion to add some AGM backup power goodness to our og Yeti1000 lithium station. Works a treat, buuuuut: I noticed it's having a hard time fully filling up the agm battery we've got installled as its 'Tank'. When connecting the 120w power brick to the Link it charges up three bars fully and then keeps bleeping the fourth on/off. Multimeter says the AGM peaks out around 13.2/13.3v surface voltage which seems fine and full, but here's the twist: when I connect either an external AGM charger ór the Goalzero Guardian 12V solar charger to the agm battery, both of them start a quick round of absorption charging at a high voltage (14.8+) before settling at an actual agm float charge voltage (dripping in the 13.8-15v range).


Now, could be the agm has a crappy cell (it's not new), confusing the charge controlllers. If not, my theory is the Link expansion which is just another charge controller, with its max 12.5 65A rated output doesn't actually do correct AGM charging cycles at the necessary voltages. That would be weird because I understand the 'official' Tank product contains an agm battery; however since both my external chargers have the agm battery floating at the correct voltages and the Link just 'stops' charging, this looks to be the correct conclusion.

I've read similar experiences mentioning the Link 'doesn't charge external batteries above 80%", and if it just does an absorption phase and then kinda supply charging at a too-low 12.5/13v this would be the result.

Any thoughts out there?

Cheers

(PS I'll probably be hooking up 300w of solar through an MPPT directly to the agm batteries anyhow, because the crappy 150w max you can push into them through the single Link 8mm pole will never be enough to keep them topped up anyway. Bizarre product dev choice btw: it can push 65A@12v into the Yeti, but it maxes out at something like 10A the other way into the Tank?)

· Share on FacebookShare on Twitter

Answers

Categories