Ducato starter battery

[aandncaravan]

Yes the Battery Master will trigger if the Solar Panel raises the habitation battery voltage, but remember the Battery Master draws continual power from both battery banks all the time, as it is constantly sampling the voltage of both batteries to look for changes.

 

While the current drawn isn't high, the drain on both batteries over a 24 hour period can be higher in the winter than the Solar panel is putting in.

Additionally, the Battery Master is a battery charger and as such won't be 100% efficient, typically 80% efficient. So they can sap/waste around 20% of the charge they transfer. In other words for every 10 amps of real charge into the Starter battery, they may draw 12 amps from the habitation battery.

 

That isn't much, but in association with constantly depleting both batteries watching for voltage changes, it can be significant during the exact winter storage periods when every milliamp is crucial.

 

 

The other similar devices like the CBE and Sterling Batter 'Maintainers' only monitor the habitation batteries, not both batteries, and the Sterling has very high current transfer efficiency so the impact they have is less. If you must use a Battery Master style device, the Sterling is the best.

 

 

A dual battery Solar Regulator will have none of these losses and tends to be higher efficiency than the single battery Solar regulators used with Battery Masters. Therefore, swapping to something like a Votronic MPPT can result in over 50% improvement in Solar gain through the Winter.

 

 

So yes, now that we have slightly longer days with more effective Solar capability, your system will probably be harvesting more power than is being wasted by the Battery Master.

 

 

 

[Fiat Ducato]

aandncaravan - 2018-02-25 1:09 PM

 

Dipsticks, I did understand what you wanted to do by reprogramming the American optimised Solar regulator to compensate for it's current working, but I am not sure it is worth the effort as setting it optimally for one situation is likely to result in it needing reprogramming for another.

 

I have no idea how American RV's are used in the States so I don't know what an American Morningstar Solar Reg will be optimised for. Just because it works for users in the States, doesn't mean it will be optimum for UK users.

For example do they always use EHU or rarely use EHU? Do they leave Solar active all year or disable it when no charge is required? What size battery bank is typical? Do they use the vehicles more often than Europeans and maybe hire them out in between usage? Do they travel longer distances between stops relying more on the Alternator to replenish the batteries?. What battery technology is the most popular, it used to be 6volt high Antimony content batteries, but that may have changed. What electronics are installed and what is the typical charging profile, Etc.

 

 

I am not a Morningstar expert but several things seem clear.

First your battery fluid loss seems very high, indicating an issue of some sort? That may be from a failing battery, but just as likely overcharging of the batteries.

 

Secondly that the default Absorption 'boost' charge voltage is a very low 14.0v. This will lead to longer charging times but may have helped reduce your 'overcharging' fluid loss which may have otherwise been greater.

Setting it to the usual 14.4v will charge the batteries faster but may also result in an increase in fluid loss if the vehicle isn't used regularly?

 

The Float voltage of 13.7v is higher than most battery manufacturers state is ideal but remember that in this regulator when the Absorbtion charge Timer ends on the Morningstar, all the remaining charge is put in at the 'Float' voltage.

Most people think that a battery charger drops to the Float voltage once the battery is 'fully charged' but it doesn't. It usually drops to the float voltage when the 'Fast' charge timer expires. See our webpage on how a charger works : http://www.aandncaravanservices.co.uk/how-does-a-charger-work.php

 

So reducing the Float to 13.2v might mean that 10 hours charge is at this low voltage and only 1 hour at 'Fast' charge. On a discharged battery that might result in only partial charging versus all day at 5amps and 13.8v..

 

The default Timers seem to give 60 mins at 14.0v at the main 'Boost', or fast charge, when the Solar regulator first wakes up each morning.

Bear in mind that in June in the UK, that will be about 05:00 when the Solar Panel current may be well below it's peak current as the Sun is still low in the Sky.

In other words the 14.0v Boost charging takes place when the Solar Panel current availability is low. The Boost 14.0v timer probably expires just when the Solar Panel is getting into it's stride as far as current is concerned.

 

 

This is partly offset by a second timer, set at 2 hours by default, that seems to replace the usual 'Boost' timer if the battery is low - Time before Float : Low battery.

 

 

Suggest the Equalisation section is disabled as this is primarily aimed at deliberately overcharging the battery to de sulphate it. Something almost all battery manufacturers say should not be done and most experts agree does more damage than good.

 

 

So while you can alter the values, it may be a compromise for all situations.

 

 

I would suggest it would be a better option to fit a Votronic MPPT where all the values are likely to be optimum for European use.

Votronic and Schaudt are among the few companies who understand Motorhome use, Battery charging and Solar so more likely to create a Solar Charger that fits UK users better than anyone else.

 

 

We would still advise you enable Solar in the summer months only when the batteries need charging.

 

 

 

Hi Alan just read this thread and found it really interesting but a thought popped in my head, you are talking about best optimum voltage rates for charging of Leisure batteries - yes? What happens say your travellling around Europe in your motorhome covering 100- 200 miles a day. Most people have their vehicles set up to split charge when drving along, the voltage from this in most older vans isn't monitored it just constantly charges at around 14V - 13.8V. Is this bad also for your battery and if so what can you do to help prevent over charging?

[aandncaravan]

Yes a continual 14.4v for days or weeks at a time isn't ideal for a wet acid battery, and an absolute killer for an AGM battery.

But you are talking about situations of only hours during a period when the battery is being used.

 

The above thread is talking about situations when a modern battery, that doesn't even self discharge at the rates they did 5 years ago, is totally idle, no drain on it at all so doesn't need any charge.

 

On a vehicle journey, just as when you are in the vehicle using it, the Control Panel will be 'On' and drawing about 0.2 - 0.4 amps and this type of draw on it's own can take the edge off 'floating' a battery that doesn't want or need any charge.

 

If you add to that the Blower motor, Radio, lights, Wipers, etc that might be taking power, it all creates a 'usage' where the battery is likely to actually 'want' or not mind a charge.

 

The combination of usage and short duration shouldn't cause a wet acid battery any harm.

 

 

 

[Fiat Ducato]

Thanks for clearing that up for me, I knew you would be able to explain it. Just often crossed me mind that was all.