Re: Solar/MPPT or Multiplus during winter lay up?

James Alton


    Some gel batteries have such low self discharge rates that it might be best to just unhook them to insure there are no phantom loads and don't do any charging.  The Sonnenschien Gels that I have been using can sit on the shelf without charging for up to 2 years according to the manufacturer.  I unfortunately  ended up going almost that long without charging due to COVID travel restrictions to Greece and despite my batteries being quite old they were fine when I returned.  So maybe check with Victron to get their guidance since there are various gel chemistries.  The most critical thing about gels is to avoid overcharging them so there is always some risk leaving an unmonitored charging source on a boat.  Overcharging can boil the electrolyte out you cannot replace it.  

James Alton
SV Sueno,  Vonista, Greece

-------- Original message --------
From: David Crisp <david@...>
Date: 9/25/21 11:02 AM (GMT+02:00)
Subject: [AmelYachtOwners] Solar/MPPT or Multiplus during winter lay up?

Wilna Grace has twelve new 110AH Victron Gel batteries and I'm keen to look after them carefully! The bank is charged either by solar and a Victron MPPT 100/50 or a Victron Multiplus 24V 3000W 70A.

I am about to store my boat onshore in Greece for the winter (6 months) and I am wondering what the best way is to leave my Gel batteries powered with the solar/MPPT or Multiplus? I ask because I note the Multiplus has a storage mode whereas the MPPT does not.

David Crisp
SV Wilna Grace
Amel 54 #58

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