Re: Converting my Amel 54 to lithium batteries: what I did, what I like and what I don't like (after one year of full time live aboard use)

Sv Garulfo
 


It disconnects the batteries altogether. There is ‘only’ one pair of poles on the battery. I’ve seen lithium setups where the loads and the chargers were on separate pairs of poles. If that is your case, i guess you could put the relay on whichever pair is appropriate. 

On a side note to follow up on the 90%SOC management in the MasterVolt set up, i programmed the ‘battery full’ event to put the MPPT in float state, where it feeds amps as per the load requirement and only drips a few amps into the batteries. 
It does not seem to go back to ‘bulk’ if the SOC drops back below the ‘battery full’ level, bit it would based on the “return to bulk” voltage. The next day it automatically switches back on with daylight in bulk mode. 

I also set the Alpha Pro alternator regulator charging mode to “suspended” upon the ‘battery full’ event. Again it does not fall back to charging below that level, so I created a button to turn the charging ON/OFF manually. 
I need to test what the float mode of the alternator does to see if that’s a better state. 

I haven’t tried the battery charger yet but I guess i would just set it on float state and it should just feed the loads and keep the batteries at 90%SOC, for instance for long term on shore power. 


Best,

Thomas
GARULFO 
A54-122
Fakarava, French Polynesia 


On Mon, 7 Oct 2019 at 09:29, Scott SV Tengah <Scott.nguyen@...> wrote:
Thomas,

Do your ML7720B disconnects completely disconnect the battery? I would like to simply disconnect the loads,  but allow the charging circuits to remain intact as our Victron VE.BMS has separate triggers to cutoff charging (overvoltage or over temperature) and load (under voltage). 

I talked to Victron about using three BP220 load disconnects, one for each battery, but two problems arose: (1) the BP220 is not bidirectional with respect to current and (2) I don't want to disconnect the battery, just the load.


--
Scott 
2007 A54 #69
SV Tengah
http://www.svtengah.com

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