Jump to content

Do inverters become less efficient with age?


Obone

Featured Posts

Thank you for your reply.

I have a lot to learn about batteries.

Do boaters monitor currents? My knowledge extends to the use of shunts, but I do remember the monitoring system we used having 

a level of complexity I don’t really want on board.  

Further to nicknorman’s last post, it is noticeable that the batteries do have greater capacity on the first evening out from the Marina after the batteries have been on long term charge via the combi unit.

Link to comment
Share on other sites

1 hour ago, Obone said:

Thank you for your reply.

I have a lot to learn about batteries.

Do boaters monitor currents? My knowledge extends to the use of shunts, but I do remember the monitoring system we used having 

a level of complexity I don’t really want on board.  

Further to nicknorman’s last post, it is noticeable that the batteries do have greater capacity on the first evening out from the Marina after the batteries have been on long term charge via the combi unit.

Yes boaters monitor currents. Well the ones who want to care for their batteries, anyway!

 

A shunt based ammeter is fine. However when you come to price up a decent one, it can be just as cheap to get something like a NASA or victron monitor which monitors current and also adds it up to give AH. This allows you to get a pretty good idea of battery health ie how much capacity as a % of original capacity, is remaining.

Link to comment
Share on other sites

21 minutes ago, Obone said:

Is this the type of unit you refer to?

Nasa BM1C Compact Battery Monitor - White

Yes that’s the sort of thing. The only issue is that the maximum current it can take is 100A. You don’t specify what power of inverter you have but really you should spec the monitor to be able to cope with the maximum current the inverter can take, plus a bit for the boat’s other services, even though at the moment you don’t think you will use it. I would therefore be inclined to go for the BM2 as it can take 200A and is only a little more expensive.

  • Greenie 1
Link to comment
Share on other sites

31 minutes ago, George and Dragon said:

I think you need to take action to protect the batteries at about 12.7 volts (others will know more than me). 

You are correct with one of those statements.

 

A 12v battery is fully charged at around 12.7 volts

battery-state-of-charge.jpg

Edited by Alan de Enfield
Link to comment
Share on other sites

36 minutes ago, George and Dragon said:

I think you need to take action to protect the batteries at about 12.7 volts (others will know more than me). 

12.7 to 12.8 volts RESTED is as good as fully charged so the only action you need take there is to stop charging but a modern battery charger will do that for you as will a decent solar controller while if you are using an alternator the your mode of use and the aternator's voltage regulator will take care of it.

 

The "magic" voltage at which you really should take action is around the 12.2 to 12.3 volts RESTED and the action is to:

1. Stop discharging.

2. Start recharging ASAP.

 

This is because the majority of batteries used on inland boats do not react well to being discharged much below about 40% and by only going down to 50% you save some of the batteries' cyclic life. That voltage is not written in stone so going below it on the odd occasion is unlikely to do noticeable harm to the battery. What will do harm is leaving the batteries discharged for any longer than absolutely necessary.

 

 

Link to comment
Share on other sites

  • 1 month later...

Thank you for everyone’s advice re our inverter. 

We are limping on through the season with our poorly batteries, and mainly avoiding using the inverter.

 

My thoughts are now turning to installing new batteries next season and modifications that may be easily made to our charging system. 

We have an older Stirling Combi unit.

 

The biggest issue it seems to me (apart from the inherent inefficiency of the inverter) is that our combi inverter will only allow battery charging and producing 230v at the same time. There is no option to have each function individually. As a result I am unwilling to leave the unit on for extended periods over the winter. What would be the best way round this set up or what would be the easiest solution?

Link to comment
Share on other sites

If you mean leaving it on shore power over the winter, this a problem with earlier Sterling inverters. I believe later models did what Mastervolt and Victron do which is to have “charger only” setting, thereby ensuring that if the shore power goes off it doesn’t start inverting. I suppose something could be lashed up - a 230v relay that would detect the presence or otherwise of shore power, and turn off the whole unit when the shore power wasn’t present, but it would mean intercepting the on off function on the Combi’s panel which would be beyond someone not electronically competent.

Link to comment
Share on other sites

23 minutes ago, Obone said:

Thank you for everyone’s advice re our inverter. 

We are limping on through the season with our poorly batteries, and mainly avoiding using the inverter.

 

My thoughts are now turning to installing new batteries next season and modifications that may be easily made to our charging system. 

We have an older Stirling Combi unit.

 

The biggest issue it seems to me (apart from the inherent inefficiency of the inverter) is that our combi inverter will only allow battery charging and producing 230v at the same time. There is no option to have each function individually. As a result I am unwilling to leave the unit on for extended periods over the winter. What would be the best way round this set up or what would be the easiest solution?

But if you only want a trickle charge over the winter then I would buy a small marine charger from a reasonable brand.  If it’s just to compensate for battery self discharge a solar panel will also do the job.  The question is “how much power will you use per day during the winter period?”

Link to comment
Share on other sites

Generally we isolate the batteries when we are away from the boat, so the only draw would be the bilge pump, and if that being used a lot then I guess we have a rather more serious issue!

Also will a trickle charger be suitable to attached across all four leisure batteries at the same time?

Link to comment
Share on other sites

26 minutes ago, Obone said:

Generally we isolate the batteries when we are away from the boat, so the only draw would be the bilge pump, and if that being used a lot then I guess we have a rather more serious issue!

Also will a trickle charger be suitable to attached across all four leisure batteries at the same time?

If you mean that the 4 leisure batteries are permanently wired in parallel as one bank then yes.  Personally as it’s just self discharge and the occasional bilge pumping, then I would use solar, but then I like solar as it’s independent of external supplies.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.