Supreme caravan charging issues

Hi Sam

What size is your fridge?

What amps do you see coming in from the solar?

Weather conditions and whether you were parked/travelling in the open or in shady conditions would also have an effect.

I have set our controller to 14 v for our AGM batteries. It could go a little higher, but we have a trickle charge form the battery so left and allowance for that.

Motherhen

G`day sam h6,

If what I understand about calcium batteries is correct, (quite often I am wrong, and I hope someone here will correct me if I am)
For the solar to charge a calcium battery to 100% charged it will need to deliver a minimum of 15.1 volts at the battery.
The 25 amp 3 stage charger will have to deliver the same voltage (15.1 volts) with the 3rd stage, ie the float charge stage.

Calcium Batteries are lead acid batteries, the lead plates have a small percentage of calcium in them.
They are supposed to have heaps of advantages that the marketing people are only too willing to sprook about. Then there are others that are ignorant of the specifications.
What they DON`T tell you is that very few vehicles have an alternator capable of supplying sufficient voltage, 15 volts +, to FULLY charge them.
I refuse to use a Calcium Battery.

Scrubby.

Sam, A couple of points.

1. Is the frig empty? An empty frig will consume a lot of energy due to a low thermal mass.

2. Calcium batteries require an equalizing setting of 16 volts. The normal bulk charge should be at least 14.4 volts followed by a float of 13.8 volts.

3. The settings of the 240 volt charger and the solar controller need to be reviewed.
you refer to a Baintech charger, is this a Ctek? These have a calcium battery setting. The charger should bring the batteries up to full charge. If the charger has a "power supply" setting. I suggest you switch to that setting when you get the basic problems sorted. The "power supply" setting will prevent the batteries from being over charged with a load connected. Clearly you have other issues. It almost sounds like the 240 volt charger is not contributing any charge

4.Check the solar controller manual for "battery Type" settings. If it doesn't have a calcium setting I would select "flooded" or "AGM".
can't understand why it has been set to cutout at 13.7 volts, unless this is the float voltage. What brand is the controller?

Look forward to your feed back.

Like Motherhen we have a 130 L Vitrifrigo, the one with the remote compressor unit.
They use a Danfoss compressor, BD35 on ours, yours may well be a larger but similar unit.
The Danfoss controller changes the compressor revs as the load changes to minimise power usage and increase efficiency. Ours pulls anywhere from just under 4 amps down to about 1.4 depending on the load.
I reckon you have two problems, the wrong charger for the batteries if it doesn't have a Calcium setting and the wrong settings on the solar controller. As others have said calciums need a much higher voltage to charge correctly and if they are only getting 13.8v max then they are probably (guessing) that they are only 50% charged at best.
The other "problem" with the Vitrifrigo is a lack of insulation around the cabinet itself, not really designed for our climate. If you can add 50mm of insulation to the outside of the actual fridge cabinet you will notice that it runs far less and uses, in our case, approximately 25-30% less power due to shorter run times.
I just bought high density polystyrene sheet insulation (blue, also comes in a pale pink colour as well) and stuck it to the outside of the fridge, virtually doubling the wall thickness of the cabinet. If you have more space around the fridge then make it thicker again.

Well the charger has no settings what so ever, it is simply a biantech brand no other names on it.

The solar control is a Juta and the instructions have such bad English that I struggle to follow them, obviously written by someone who speaks a different language. Before anyone rips me no I am not racist at all but this instruction book is poor.

There are no settings at all for battery types on the control. I have been all through this and it's driving me nuts. The standard response from supreme is the control should not be touched as they know how to set them up and we should not adjust them, i have since cranked it up to 14.6 volts as the label on the battery says max charge volts 14.7. also yesterday I was informed by one of their techs that running my fridge will flatten the battery in half hour, it should be run on gas. Believe it or not I had just spent 10 minutes explaining that I hade a vitrifrigo with a danfoss compressor!!! After getting a little frustrated and pointing out the issue again he replies " oh never heard of those before".

The other issue is they only run 6 mm2 wire throughout the whole system and 8 mm, not b&s just mm, to the charge plug for the vehicle. I am not a qualified auto elec but the industry I work in involves a fair bit of it and I nearly had a heart attach when I took a close look at the wiring.

Hi Sam
We have a Vitrofrigo and had major problems till we upgraded the wiring to 8mm cables to the batteries. But it sounds like you need a better charger as well, can't go past a 2500 CTec charger. Good luck it can be very frustrating getting it right.
Cheers
Rick P

Thanks to everyone for your replies it's great to get opinions from real travellers with real experience, not someone who is paid to tell me what I want to hear.
We are booked to call into the dealer Monday morning for our "first service" and sort out these issue. After reading all the replies and talking to several auto elecs today I will be pushing for a new 240 charger, and I guess I will be forking out for a new solar controller as I can't prove theirs is not fit for purpose.

If any of you in your travels see someone looking very frustrated and drinking warm CC& dry outside a supreme caravan, it will be me because the batteries have gone flat!!!
AGAIN!!!

Hi sam,
I have a different set-up and do a lot of free camping.
Nothing is more power draining than a fridge, and I always recommend one that runs on gas if free camping, though it may not be quite as efficient.
Hot Water heater also on gas.

Glass matt batteries recharge in a few hours compared to standard deep cycle batteries, and are recommended.
My solar settles on 13.8 volts as fully charged, and I have a total of around 300 watts on the roof.
I have done many 8 week trips and never needed to run a gennie or hook up to 240 volts, including Tassie.
My biggest power use is probably computers and the TV. All lighting is low power LED.
All my wiring is above spec size wise.
It's better to have extra panels rather than three batteries to maximise solar.
That's just my system and works for me, others are free to disagree.

I would check the power consumption of the fridge.

I believe that it will more likely be drawing up to 7 amps for anything up to 12 hours a day.
Ie 90 - 100 amp hours.

Disconnect the solar and then check the current draw.
Or check the specs.

If the wiring is not sufficient you will always struggle to provide enough power to the fridge. If it is adequate, then your batteries will always struggle to have sufficient capacity for it anyway.

You certainly do not have sufficient solar panels for that fridge.
Your panels under the best conditions will be able to supply about 6-7amps each.
That for about 5 hours on the sunniest of days adds up to a maximum of 70 amp hours.

If you are not adding to the charge with vehicle connected DC-DC charging, your fridge will consume more than the solar can ever provide.

The suggestions would be any or all of:
Replace the calcium batteries with Fullriver AGMs;
Add two more 130watt solar panels;
Ditch the solar controller and fit a couple of Morningstar Sunsaver Duo;
Rewire the fridge to use one battery and the house supply to use the other;
Check out the Charger very carefully and probably replace it with an adjustable three or four stage charger;
Add a pair of DC-DC chargers from the vehicle to better put charge into the separate batteries when driving, or one if the batteries are still connected in parallel.

Without at least replacing the mains charger it would look as though your round Aus trip is unlikely to proceed this week, and free camping will anyway be severely restricted.

Ken

Be very aware there is a hell of a lot of misinformation running around about batteries and charging and what this or that battery will do....but I'll let that pass for now.

first and most important....all good changers, both solar and mains are looking for a direct relationship with a single battery.....they may tolerate a bank of batteries.

when we have two chargers connected to the same battery powered up or not we run into problems...

SO

Do you have the solar and the 240V charger connected at the same time?......Don't.

one charger connected to any given battery at any one time...unless the system is specifically designed otherwise.




On the matter of the fridge....is this a compressor bassed fridge or a 3 way fridge that will run on gas.

If it is a 3 way fridge that runs on gas, they are incredibly inefficient on either 240V or 12 volts.....on 240V who cares you are on mains......on 12 volts 3 way fridges are only viable when the engine is running, because they draw heaps and all the time.

A complication is that 3 way fridges are almost always wired to 12 volts in cable that is far too small.......efficiency then suffers.


By all means run the 3 way fridge on 12 volts when traveling, but when you stop run on gas.


On cable issues.

We live in a metric country, anybody who knows their business about electrics will be talking in square milimeters when refeering to cable.......yes there is plenty of American Wire Guage cable about, but to do any calculations we must convert to mm.

8 guage is close as damit to 8mm2...in fact "proper 8 guage" is 7.91mm2.

On the matter of the charger......don't worry about the settings or the side issues about what voltage people claim you need to charge this or that battery.......get that battery charger hooked to the battery on its own with no solar and no other load and see how it goes.

As for the notion that you can charge a "glass mat battery in only a few hours"...that is false....SOME AGM batteries may tollerate and accepet charge faster and better than others but...there is no free lunch and some AGM have very limited charge rates.

no matter what the battery, if it is at a low state of discharge regardless of the size of the charger or battery capacity expect charging to take time think in terms 8 hours minimum or over night rather than the " few hours".

cheers