Does my solar / battery charging seem right? (1 Viewer)

[Checkingout]

Hi all, I have a new m/h and as it is my first, I am not sure what to expect out of the kit I have fitted and whether I should get it checked out. It has been built in Italy (Rimor 109), on a Renault Master chassis, which I assume has at least a 110A output alternator. I have two leisure batteries which I believe are 110Ah each and 2 x 160W solar panels (these were dealer fitted, not the Rimor factory). When we first picked the m/h the batteries showed up around 13V plus however and stayed up there although we were plugged in a lot to start with.

We are about a month into our travels and usually stay off grid however over the last week we have either parked under trees or the sun has been sadly lacking so solar hasn't had a lot of sun.
The result was that leisure batteries had dropped down to around 11.5V. I ran the engine for 5 - 10 minutes a couple of times which gave them a bit of a boost.
Today we had quite a long drive (1 1/2 hours) and I expected that with the alternator pumping into the batteries we would be back up around 13V again however it was just up around 12.5V. I have plugged in for a couple of hours and we are now over 13V.
My questions are should I have expected that the drive would have brought the batteries up to full charge, should I expect them to charge to 13V plus off the alternator/solar and does this look like something I should get checked out.
We are intending to live off grid for a couple of years and I am quite disappointed at how little charge the solar gave when the sun wasn't strong, how little charge running the engine for a few minutes gave and how long it took the alternator to boost the batteries when travelling.

Maybe I am being unrealistic, so looking for the advice of the wise ones on this forum

 

[BwB]

Have you checked into the drain on your 12v system to make sure you haven't got something eating away at your battery? For instance - my previous motorhome had a switch on the fridge to heat the door surround between the fridge and the freezer which I didn't initially know about (and it had been left ON). This really ate into the battery levels. Solar is great but has it's limitations and batteries do take a long time come back up if they dropped as low as you stated. Especially if parked in the shade.

 

[Stealaway]

I think you will need to monitor how much you take out. Never let your batteries drop below 12.25v. Ideally you should have a amp meter so you can see the solar panels charging rate. To recharge the battery by the engine alone could be 4-5 hours
Could you cut down on the demand from the batteries?

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[pappajohn]

What you are seeing is the charger voltage, be it alternator, solar or hook up....not the true battery voltage.
Batteries need time to charge no matter what your alternator or solar output is.
Running the engine for 10 mins will make no difference to the battery capacity, you are only seeing the float charge which means nothing.
A flat battery, below 12v, will take many hours of engine running to fully charge due to the thin gauge split charge wiring and the alternator sensing the engine battery voltage, which will be fully charged, and reducing output to a minimum.

 

[Fletton]

It will all depend on the following....

The state of charge prior to being off grid...

Your daily useage ... i.e big on tele watching etc?... lots of lights on - albeit LEDS...

I have 2 90AH leisures... and 100w solar....

I don't watch the box that often... but have cab radio on ..

I heat the water once per day; only use minimal lights... ( one led above seating and a strip led above worktop when cooking when it gets dark..

Use the water pump.. shower, kettle, loo etc...

Have my iPad and or phone on charge most of the time...

Mifi plugged in - on constant charge...

And usually find the solar controller is showing a float charge by late morn...

Or mid pm if i've succumbed to tele or its a dull day...

 

[mitzimad]

the most you will see from a 12v battery is 12.7 fully charged anything above that is from another source' after removing a source of charging you will see a float charge for a while after

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[Checkingout]

Thanks everyone for your explanations and yes after removing the external power lead and with no sun, the charge was showing at 12.6/12.7V and was still showing 12.6V this morning after watching House of Cards last night. Obviously I was being a little optimistic in expecting that the alternator would re-charge so quickly after allowing the batteries to discharge so much. Lessons learned about not allowing the batteries to discharge so much, being more aware of where I park and being more careful with power especially when planning to be off grid and if the weather forecast is a bit grim.

Would leaving the inverter switched on draw much current? Should this be switched off when it isn't needed?

 

[Infinity31]

I know a lot of people will say otherwise but an alternator is not designed to charge batteries. It's job is to run ancillary equipment like lights, heater, AC, wipers etc when the engine is running.
It certainly won't fully charge a depleted battery as your experience proves. The multi stage intelligent charging of a B2B charger will do the job though.

 

[TheCaller]

Would leaving the inverter switched on draw much current? Should this be switched off when it isn't needed?

Not a vast amount, but enough to make it well worth turning it off when not in use.

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[Don Quixote]

Firstly your batteries are now depleted and will not hold the charge. There are lots of good reading about batteries on this forum, which when you have a chance read.
Running your MH for a 90 minute drive will not charge your batteries, it would take around 5 or 6 hours. Then there is the solar charge. On a good day with NO cloud cover your might at best...... with what you have fitted get enough (around 25amps across the whole day in Australia, providing your not taking out amps from the batteries at the same time as many do parked up!) to top up what you take out of your batteries (when you get new ones that is) as your current ones will not hold any charge now as they have been allowed to drop below 12.4volts.
The average MH draws around 25amps a day - your have 220 amps, but really only 110 amps ( never allow batteries to get below 50% ) so - after 4 days of parked up unless you have clear skies your batteries are reaching the stage of no return..............
Many think as soon as they plug into EHU all is well as they see 12.7volts or better all day long........... and believe that their batteries are fine.......... that is until they try and run without EHU and then the penny drops...... as does the voltage!
I worked with batteries for 26 years and used to advise on here, but after being short down many times by the so called "know it all's" I no longer bother. In a nut shell you need new batteries.
I forget to say enjoy your MH in Australia ( we loved it there when wife was serving with Australian Army) it is a steep learning curve, but there are many members on here who are great and very helpful.

 

[Don Quixote]

Thanks everyone for your explanations and yes after removing the external power lead and with no sun, the charge was showing at 12.6/12.7V and was still showing 12.6V this morning after watching House of Cards last night. Obviously I was being a little optimistic in expecting that the alternator would re-charge so quickly after allowing the batteries to discharge so much. Lessons learned about not allowing the batteries to discharge so much, being more aware of where I park and being more careful with power especially when planning to be off grid and if the weather forecast is a bit grim.

Would leaving the inverter switched on draw much current? Should this be switched off when it isn't needed?

If you are using an inverter to run TV and the like you will be drawing 12volts to be converted to 240 volts and this is a waste of power. Try and run everything on 12volts like TV, charging phones etc. As some have stated above a B2B is a must if your using an inverter. A B2B will fast charge your batteries on tick over in about 25 minutes. One of the best things I fitted to the MH.

 

[Wildbill]

If you are using an inverter to tun TV and the like you will be drawing 12volts to be converted to 240 volts and this is a waste of power. Try and run everything on 12volts like TV, charging phones etc. As some have stated above a B2B is a must if your using an inverter. A B2B will fast charge your batteries on tick over in about 25 minutes. One of the best things I fitted to the MH.

And if any one should know about battery you should sigs
Bill

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[TerryL]

Two 110ah batteries, 100w solar panel and a Sterling B2B charger, plus a battery master to top-up the cab battery if needed. With this setup we've never had a problem, only using hook-up if it's available without extra cost. You do, as you suggest, have to be a bit careful if the weather isn't so good and always bear in mind what you are using - inverters can be a battery killer. Last year in Morocco we noticed the batteries weren't holding their charge so well, but they were over 5 years old so before we went away again we replaced them; they don't last forever.

Letting a battery get down to 11.5v is a sure way of killing it, but if you recharged straight away you just may have gotten away with it, time will tell.

 

[Saltings]

Having read the notes that Don Quixote wrote, which make a lot of sense, I can understand why our 110 Ah batteries (cab and hab both 110 Ah) probably need replacing this Spring. The cab battery is from 2014, so 4 years old but never run flat, and the hab battery is only 2 years old but has run flat, after which it has always been charged on a regular basis. The CTEK charger does a good job as it also refurbs the plates, but as Don Q says, nothing lasts for ever.