Batteries and Charging

[Tony Brooks]

Don't blame "old alternators", it is not their fault. When our battery plates were mainly lead antinomy the gassing voltage was rather lower than the lead calcium ones commonly used so the alternartor's regulators had to be set accordingly.

When alternators became common the regulator setting was usually around 13.6 to 14 volts, then quickly it became 13.8 to 14.2 and now its more like 14.2 to around 14.5.

Of course these higher voltages suit lead calcium batteries better and will charge a given battery faster than 13.6 volts but given time 13.8 volts will fully charge a battery but we do not have that time unless on a shoreline. However it is not simply a question of higher voltage the faster the charge because some electrical energy is potentially lost to heating and gassing. I am at something of a loss to know how full traction batteries with lead antinomy plates get on with modern alternators apart for demanding frequent topping up.

I agree with Dave that a SUITABLY SET UP Adverc is a useful addition on older systems but am not convinced they  are cost effective with system that charge in excess of 14.5 volts. Gibbo did agree once that they were the best of the bunch. The Sterling A to B was designed to overcome battery charging problems on system much more sophisticated that our boats and in my view are unlikely to be as cost effective as an Adverc or ordinary Sterling alternator controller. In any case they make fault diagnosis more complicated than simple controllers.

 

 

[dmr]

I usually charge our Trojans at 14.8volts or even a touch higher in winter and the topping up is not excessive (until they get old). I do wonder if its the Adverc voltage cycling really helps here, that is what it was designed for after all, but I have always been a bit sceptical. On a liveaboard boat in Winter the difference between 14.6 and 14.8 really is significant. I have a standard Beta/Iskra (Letrika) 100amp alternator and this charges at about 14.4 without the Adverc so not all modern alternators are 14.6+

The Sterling AtoB is a big lump of power electronics but its main purpose is to replicate the advantages of an alternator controller in situations where it is not possible to make the small modification to the alternator that a conventional controller requires. It also does complicated switching between the starter and domestic batteries which is...well...complicated.

I like my setup:

Starter alternator at 14.6, domestic alternator at 14.4 or less but cycled up to 14.8 with the Adverc, Alternators paralleled during bulk charge, 6 Trojan T105s, and a TravelPower.

.........Dave

 

[Dr Bob]

59 minutes ago, Tony Brooks said:

Don't blame "old alternators", it is not their fault. When our battery plates were mainly lead antinomy the gassing voltage was rather lower than the lead calcium ones commonly used so the alternartor's regulators had to be set accordingly.

When alternators became common the regulator setting was usually around 13.6 to 14 volts, then quickly it became 13.8 to 14.2 and now its more like 14.2 to around 14.5.

Of course these higher voltages suit lead calcium batteries better and will charge a given battery faster than 13.6 volts but given time 13.8 volts will fully charge a battery but we do not have that time unless on a shoreline. However it is not simply a question of higher voltage the faster the charge because some electrical energy is potentially lost to heating and gassing. I am at something of a loss to know how full traction batteries with lead antinomy plates get on with modern alternators apart for demanding frequent topping up.

I agree with Dave that a SUITABLY SET UP Adverc is a useful addition on older systems but am not convinced they  are cost effective with system that charge in excess of 14.5 volts. Gibbo did agree once that they were the best of the bunch. The Sterling A to B was designed to overcome battery charging problems on system much more sophisticated that our boats and in my view are unlikely to be as cost effective as an Adverc or ordinary Sterling alternator controller. In any case they make fault diagnosis more complicated than simple controllers.

 

 

By raising the 'alternator' issue, I was not blaming them. I raised it because I see little discussion that these old alternators exist (in the 5 months I have been on this forum). The fact is there are boats made in the 2002-2005 timeframe that have poorly performing alternators and if you will need to do something about it if you want to exist off grid.

A number of people, including you Tony, poo poo'd my comments in a thread in June that a Sterling AtoB would be useful - I had one on the lumpy water boat and the batteries lasted 5 years no problem - and would increase the speed of charging significantly. The general concensus was that I was daft even thinking the Sterling would speed up the rate of charge.  Now I have had my AtoB on the nb for a while I can confirm that it is getting me to full charge** much faster (assessment based on tail current and voltage at rest the following morning). I cant comment on cost effectiveness as I have not looked at the Adverc and did not just want to put a new alternator on (Sterling AtoB gives more control and as Dave says deals with the starter battery as well) - but went for it because it worked so well on the previous boat.

The point I am trying to make is that there are likely a lot of aging boats out there with poor alternators (ie designed to address different issues) and their owners should think about options to improve. I chose the AtoB based on previous experience and am very happy with that decision.

 

** and by full charge I mean full (ish) ie 95 -98%...if the rest only happens slowly when the system goes into float and no solar.

Edited November 3, 2017 by Dr Bob

[smileypete]

This is why I reckon 95% of boaters would be best off with reasonably decent leisure batts.

They should do OK at around 14.4V, and if not any reputable manufacturer and supplier should be willing to get involved to stand behind their product.

Sterling A to B is good but costs £300 to £400, these days that'll buy a reasonable solar setup....

Edited November 3, 2017 by smileypete

[Bargebuilder]

I remember being in the same position as the original poster and being overwhelmed by conflicting advice. I live aboard all year and have no access at all to shore power, relying on 4x 235w 12v solar panels and 3x LE300 wind turbines. These feed into my 1500Ah (at c100) deep cycle batteries.

I run a 800w Victron inverter 24hrs because I have a 'mains' fridge, a 42" tv, a pvr recorder, a computer, a compact hifi, a heated blanket and lots of 'mains' chargers. I also use 12v dc for lighting, pumps for drinking water, grey water and black water, plus a few other bits and bobs.

I'm not sure how accurate the Smartgauge is, but my batteries are currently reading 94% full and haven't dropped below 80% full since the early Spring.

I do have a diesel 12v generator, but I only used it three times last winter when the battery charge state dropped below 50% during extended dull and windless periods.

I check the Smartguage both night and morning every day for both charge state and voltage, but my wife and I live without rationing power or obsessively switching things off.

Our batteries are now 6 years old and going strong and that is without getting too bogged down with the technical stuff.

[smileypete]

That is good to hear, perhaps you could share the make/brand of your deep cycle batts?

Though I'd expect the 1kW of solar has a lot to do with it.

Edited November 4, 2017 by smileypete

[Bargebuilder]

You are so right, the solar has everything to do with it: The wind turbines by comparison are useless!

I have a fairly low opinion of the published statistics for all of the makes of wind turbines. My LE300 units on paper could output 300w, about 25 amps at 12v. I was dissatisfied because the outputs that I was achieving were consistently MUCH lower than the published output curve. I contacted Leading Edge and they had a great long list of reasons why the output from my three was hardly worth having, despite the small fortune that they cost to install. Apparently, my batteries were too full or of too great a capacity or the cabling was too thin and then I was told that my cabling was too large! The wind speed that I was measuring wasn't accurate, the air flow wasn't laminar and so on. 

If my turbine set-up isn't at least as good as most people are able to achieve then most people are going to be disappointed.

My turbines are 8 metres high on a totally flat marsh,  at least 1/2 mile from the nearest tree or building and it is a windy coastal environment.

I run 70mm cabling to the base of the mast and 6mm up to the turbine.

When the batteries are at 50% full in 50 knot plus winds, I have never recorded an output exceeding 12 amps per turbine. As an average daily output, I recon a bit over 1 amp per turbine, so my three turbines contribute the same in 24 hours that my solar panels output in just one single sunny hour.

My batteries are Rolls 5000 series, but it is all about keeping them above 50% full and allowing them to equalise accasionally, for which the solar panels are brilliant.

 

[smileypete]

1 hour ago, Bargebuilder said:

You are so right, the solar has everything to do with it: The wind turbines by comparison are useless!

I have a fairly low opinion of the published statistics for all of the makes of wind turbines. My LE300 units on paper could output 300w, about 25 amps at 12v. I was dissatisfied because the outputs that I was achieving were consistently MUCH lower than the published output curve. I contacted Leading Edge and they had a great long list of reasons why the output from my three was hardly worth having, despite the small fortune that they cost to install. Apparently, my batteries were too full or of too great a capacity or the cabling was too thin and then I was told that my cabling was too large! The wind speed that I was measuring wasn't accurate, the air flow wasn't laminar and so on.

Thing is, there's no published chart of charge current vs wind speed for the LE300, I suspect their marketing quotes watts as it looks better and implies a higher charging current for 12V than will be obtained in practice. Like putting a 240W domestic solar panel direct across a 12V batt, it won't give you 20A....

Probably best to trawl the lumpy water forums for real world experiences of a particular turbine. I expect low cut in and max output in high winds can't be combined without some sort of electronics, even so, real world experience trumps marketing claims.

 

[blackrat779]

Thanks again to everyone for the the help and information.

It was really good to read your post Bargebuilder as this seems to fit my intentions and was very positive. Whatever boat I get, I want to fit solar panels to get the most out of the batteries. I don't really want to economise that much on power but could probably cope without some things. My chief morale officer will insist on something to dry her hair apart from sunshine!

I think I will give the wind turbines a miss as they don't seem to be very efficient and really want to avoid a portable generator if I can.

Two sub qustions...Do portable generators plug into the shore power socket (please excuse my ignorance) and charge batteries via the inverter as well as supplying sockets and 12v or some other way? I am assuming inverters contain a section for controlling battery charging?

After cruising all day and replacing bulk charge, is there a setting on inverters to do the slow topping up charge that is recommended every few days to get the batteries up to 100% I guess what I'm asking is whether this has to be done manually or whether (in general) smart inverter/charger systems linked to solar panels just do this automatically.

Again, if the form of my questions is naive, please excuse me and many thanks to all of you who are taking the time out to write these replies.

Cheers,

BR  

[Tony Brooks]

 Solar panels will need their own controller unless the Victron unit has a solar input. However the more tasks you ask one piece of kit to do the more you lose when it breaks don.n Personally I would think very carefully about separate inverter, charger, and solar controller verse an all in one unit.

Solar is ideal for topping up the last 20% or so of battery capacity as long as you have enough solar output. Some solar controllers can have their various stage voltages set manually and will also do an equalisation charge when they think its appropriate. This may not be in the winter months unless you another charging source to get the batteries very well charged early in the day.

Most smart charging devices seem to drop to float voltage earlier than ideal. This will all but stop charging so you often need to turn them off and on again to reboot their system.  Raising the float voltage will compensate for this to some degree but on long summer days with little or no electricity use it might damage the batteries by over charging.

Your words "I do not want to economise that much on power" so often have lead to "why are my batteries flat" questions a few weeks/months later.  Its fine as long as you have the resources to provide the power you demand AND keep the batteries charged but if not its a start of an expensive learning process.

[nicknorman]

18 minutes ago, blackrat779 said:

Thanks again to everyone for the the help and information.

It was really good to read your post Bargebuilder as this seems to fit my intentions and was very positive. Whatever boat I get, I want to fit solar panels to get the most out of the batteries. I don't really want to economise that much on power but could probably cope without some things. My chief morale officer will insist on something to dry her hair apart from sunshine!

I think I will give the wind turbines a miss as they don't seem to be very efficient and really want to avoid a portable generator if I can.

Two sub qustions...Do portable generators plug into the shore power socket (please excuse my ignorance) and charge batteries via the inverter as well as supplying sockets and 12v or some other way? I am assuming inverters contain a section for controlling battery charging?

After cruising all day and replacing bulk charge, is there a setting on inverters to do the slow topping up charge that is recommended every few days to get the batteries up to 100% I guess what I'm asking is whether this has to be done manually or whether (in general) smart inverter/charger systems linked to solar panels just do this automatically.

Again, if the form of my questions is naive, please excuse me and many thanks to all of you who are taking the time out to write these replies.

Cheers,

BR  

There are two different things. An inverter only converts battery power to mains power, it does not charge batteries. Then there are Combination Inverters, normally called Combis. These act as both inverter and battery charger depending on whether shore power is present (genny power being the same as shore power). Some people like to have Combis because they seamlessly and automatically switch between shore power and inverter, or even a combination of the two (using battery power to supplement weak shore or genny power). Some people like to have separate inverter and charger, so if one goes faulty you don’t lose both. With that, you need a manual means of selecting between shore/genny power and inverter power. It’s a matter of personal choice.

Oh and yes, one normally plugs the genny into the shore power connector on the boat.

Edited November 5, 2017 by nicknorman

[Alan de Enfield]

26 minutes ago, blackrat779 said:

My chief morale officer will insist on something to dry her hair apart from sunshine!

Just remember that a 1000w 220v hair dryer will draw 100 amps from your batteries when powered by the inverter.

Suggest you go for a gas-powered hairdryer.

[nicknorman]

18 minutes ago, Alan de Enfield said:

Just remember that a 1000w 220v hair dryer will draw 100 amps from your batteries when powered by the inverter.

Suggest you go for a gas-powered hairdryer.

Yes it will, but only for 5 minutes, which is only about 8AH so not really a “deal breaker”.

[blackrat779]

4 minutes ago, nicknorman said:

Yes it will, but only for 5 minutes, which is only about 8AH so not really a “deal breaker”.

Phew!

BR

[nicknorman]

3 minutes ago, blackrat779 said:

Phew!

BR

Unless she has really long thick hair, in which case 10 minutes. I suggest you invest in a stopwatch!

[Alan de Enfield]

1 minute ago, blackrat779 said:

Phew!

BR

It depends on hair length - 5 minutes- Hmmmmmmmm, not in our house.

[blackrat779]

1 minute ago, nicknorman said:

Unless she has really long thick hair, in which case 10 minutes. I suggest you invest in a stopwatch!

Oh blimey, boat electrics are complicated! I've only just got my head around composting toilets lol.

Cheers,

BR 

[cuthound]

3 minutes ago, nicknorman said:

Unless she has really long thick hair, in which case 10 minutes. I suggest you invest in a stopwatch!

Or run the engine whilst she uses the electric hair dryer, so the load comes off the alternator not the battery.

[Alan de Enfield]

9 minutes ago, blackrat779 said:

I've only just got my head around composting toilets

You cannot be serious, you wouldn't, you mustn't - are you really?

Who wants to keep their daily effluent output, in a bucket under the bed (as a pet ?) for 6 months

[Bargebuilder]

Hi blackrat779,

Your new boat, once you find one, may have a nice big alternator that will leave your batteries fully charged after a day's cruising. If not, you may be able to fit a bigger one or a second one.

I have a lot of solar which is not shaded, faces south and is set for the Winter Sun's angle and so is very effective: You may not be able to manage this. The solar panels charge the batteries via a mppt charge controller.

My wind turbines are pretty hopeless, but without them I couldn't get through the Winter without having to listen to the endless droning of the diesel generator. Their 40 odd amp hours each day stem battery depletion, but certainly don't raise the overall state of charge.

If you have access to shore power and a multi-stage charger then your batteries will be pampered, as too will your wife's hair, but I have found that investing in the most energy efficient equipment is vital, as shore power is not an option where we are: There are no hair driers here!

[Bargebuilder]

The composting process produces heat, so might contribute to energy saving; better than a heated underblanket!

That is how, traditionally, melons were grown in this country, over composting manure piles.

[Naughty Cal]

3 hours ago, Alan de Enfield said:

Just remember that a 1000w 220v hair dryer will draw 100 amps from your batteries when powered by the inverter.

Suggest you go for a gas-powered hairdryer.

Or forget the hair dryer and go eu natural.

2 hours ago, Alan de Enfield said:

It depends on hair length - 5 minutes- Hmmmmmmmm, not in our house.

Nor ours. My hair is quite thick although not that long so five minutes isn't enough. 

I have found I just leave it on the boat and it looks better for it.

[Alan de Enfield]

2 minutes ago, Naughty Cal said:

Or forget the hair dryer and go eu natural.

But they are not yet boaters and not accustomed to our strange ways, and anyway, 'er indoors has already put her foot down with a hard hand and said 'not drying au-natural' (or even eu-natural)

A lot yet to learn!!

[mrsmelly]

2 hours ago, blackrat779 said:

Phew!

BR

Ive said this many times over the years and will say it again. The cheapest option long term is to trade the " Needy " wife in for a more robust model. My first wife wouldn't have lived on a boat so she had to go anyway. This model does all locks etc singlehanded and keeps her hair sensibly short so doesn't need a silly hair dryer, The initial financial hit of wife disposal can be significant but in the long term the benefits far outweigh initial costs and long term on the far less frequent costs involving battery changing.

[ditchcrawler]

15 minutes ago, mrsmelly said:

 , The initial financial hit of wife disposal can be significant but in the long term the benefits far outweigh initial costs and long term on the far less frequent costs involving battery changing.

You can say that again