Re: [Amel Yacht Owners] Charging AGM batteries

Bill Kinney <greatketch@...>

This is why you should check with the battery manufacturer for charging specifications!  Flooded batteries are pretty much all the same, but AGM varies depending on the details of internal construction.  A few tenths of a volt DO matter in the long run, especially if the batteries are on float a lot.

I just installed a Victron controller with my solar panels. None of the preprogrammed settings were suitable, I needed the "Bluetooth dongle" which allows exact programming of each step of the charging process through your computer or mobile device.

Bill Kinney
SM#160 Harmonie
Fort Lauderdale, FL
We're floating again!

On Dec 8, 2016, at 17:43, svperegrinus@... [amelyachtowners] <amelyachtowners@...> wrote:



Bill Kinney reports his AGMs are to float at 26.6V (i.e. 13.3V).  

Trojan sternly warned my AGMs need to float at 27V (i.e. 13.5V) and not more, at 25 °C; less voltage at warmer battery temperatures.  Furthermore, my Trojans call for Bulk and Absorption at 28.8, with an absolute maximum of 29.4.

I discovered that neither of my Mastervolt chargers (100A, 30A) nor the Mastervolt alternator regulator offer factory settings that match the Trojan specifications; however, Mastervolt allows the user to use a PC (or a Mac) to program exact voltages as required by Trojan.  

I believe the same capability programming capability exists on Victron.


SM2K Nr. 350 (2002)

---In amelyachtowners@..., wrote :

Thanks for the replies. It seems that the float level of 13.6v is the general consensus. My chargers, Dolphin, which came with the boat, do not have a specific AGM setting. The nearest one is for "sealed lead" which gives 13.6v float but only 14.2v maximum whereas the West Marine website says that AGMs should take 14.7v max. So I guess I'll go with that unless someone advises otherwise.

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