is it possible to have 2 leisure batteries 110 amp each connected to a 110 watt solar panel with the intention of one battery classed as car the other battery classed as van on the zig unit that way it leaves my engine battery untouched also what would i need to stop my batteries boiling over
I have been using one to service two separate batteries for quite a few years, it even allows mixing different technology, size and health state batteries. I have the optional meter, an expensive indulgence, not needed but interesting to us nerds.
There are cheap copies of it about I don't know how they compare.
Our new Bailey has a factory fitted 100W solar panel and a controller which will do two batteries. They must both be the same type. It's a Truma system and the controller does the boost charge, float charge and equalisation phase automatically so should make the battery last for years. This should stop your batteries boiling over.
It seems to be working well. The van is parked at the front of the house on the north side and the panels are completely shaded by the house at all times yet the solar always has the battery topped up to full charge in no time. The weather is really overcast with rain today.
I went for a single 75Ah battery in lieu of a 110Ah thinking that if it is re-charged every day by the solar it will be enough for us.
100W will be 8A at 12 volt so will recharge 110Ah in 12 hours at ideal conditions. There will be losses in the system and I would expect it to only charge one 110Ah battery per day.
If you want two batteries I think you will need a bigger panel or 2 x 100W.
The panel output figures posted above are highly optimistic. To start with a roof mounted panel is never an ideal situation the angle of it is just too flat to be really efficent. All that said fitting one on the roof is really convenient. I just wouldn't bet on it recharging a flat battery in 12 hours. This is in no way knocking solar panels just need to be realistic.
For what it's worth my system achieved a maximum value of just over 3 amps last weekend on a sunny day most of the time it was registering about 2 amps that is with 150W solar panel.
Edit. Tio answer the original question. The answer as indicated by others is yes. I have the Morningstar controller as recommended by Paul B and JTQU. It is not cheap and perhaps less pricey options would do the job for you.
This is the predicted outputs for a 245kWp system.
245.52 KWp 1st column is % of yearly production and 2nd column kWh for each month.
Month % of yearly production (PV GIS) Production per month (kWh)
% kWh
January 2.79% 6,446
Feb 4.43% 10,235
March 8.28% 19,130
April 10.93% 25,252
May 13.15% 30,381
June 13.25% 30,612
July 12.96% 29,942
August 12.09% 27,932
Sept 9.72% 22,457
October 6.52% 15,063
Nov 3.81% 8,802
Dec 2.07% 4,782
Total 100.00% 231,034
You can see June July etc give 3 times as much as Feb but it is also light for longer.
Feb 10 hour day
June 16.5 hour day.
I felt with a 110Ah battery not completely discharging probably only down to 50% in summer a 100W panel will probably recharge it each day. If that is the case two 110Ah batteries will need more than one 100W panel, more like two will be needed.
So Grampians question is very relevant and you need to know roughly how much power you will need each day.
Last summer we had almost 2 weeks on the battery, I had the normal 100Ah leisure battery and added another 80Ah battery in the front locker in a battery box.
To keep it topped up i had a 50w panel, it was fairly sunny and this kept the batteries well topped up.
Initially i had the panels in the van when setting up and the tint from the windows made a big difference to the power output. Sticking the panel in the sun made a massive difference.
I had also converted the lighting to LEDs so my power draw was less than it would normally be.
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Topic: solar panel dependency
