Battery planning

[robtheplod]

thanks for the replies.... we go out for ever longer cruises and power is fine then as we do long days - When we leave her plugged in at the marina its for a week or two so thats plenty of time to recover...?

[ditchcrawler]

12 minutes ago, robtheplod said:

thanks for the replies.... we go out for ever longer cruises and power is fine then as we do long days - When we leave her plugged in at the marina its for a week or two so thats plenty of time to recover...?

So you don't need a big one. I cruise for about 2 hours before leaving our boat to come home, it has 40Watts of solar and when I go back to the boat the batteries are full

[robtheplod]

Original batteries are still going strong... they date from at least 2019, so should i expect issues soon??  readings all seem ok and now they are on constant charge via a Victron solar controller rather than an old shoreline charger so maybe being handled better?  voltage each morning tends to be ~ 12.8v, but as nothing is really drawing anything i suppose this doesn't really tell me much....

 

trying to be proactive to avoid failures whilst out on the cut but also keen not to change unnecessarily.. difficult line this boating lark!

[rusty69]

8 minutes ago, robtheplod said:

Original batteries are still going strong... they date from at least 2019, so should i expect issues soon??  readings all seem ok and now they are on constant charge via a Victron solar controller rather than an old shoreline charger so maybe being handled better?  voltage each morning tends to be ~ 12.8v, but as nothing is really drawing anything i suppose this doesn't really tell me much....

 

trying to be proactive to avoid failures whilst out on the cut but also keen not to change unnecessarily.. difficult line this boating lark!

You could always disconnect the charge source and do a load test. Easy to estimate if you have an amp hour counter and voltmeter. 

[nicknorman]

1 minute ago, rusty69 said:

You could always disconnect the charge source and do a load test. Easy to estimate if you have an amp hour counter and voltmeter. 

 

If a battery has been on float for a long time, it seems to get "lazy" such that the first cycle is disappointing. It then gets better for subsequent cycles.

[Rob-M]

Just now, nicknorman said:

 

If a battery has been on float for a long time, it seems to get "lazy" such that the first cycle is disappointing. It then gets better for subsequent cycles.

That is what we find, batteries seem to perform better after we have been out boating for a few days and taken some charge out.  We are considering a switch to lithium though so going to speak to Ed Shires for a price to install.

[nicknorman]

1 minute ago, Rob-M said:

That is what we find, batteries seem to perform better after we have been out boating for a few days and taken some charge out.  We are considering a switch to lithium though so going to speak to Ed Shires for a price to install.

They are a game changer!