Advice needed my 2022 bailey caravan is fitted with a truma 100w solar panel i'v changed my battery over from lead acid to lithium 110amp battery we do 90% off grid caravaning all year round and was thinking of adding another 200w panel to the roof so in total 300w on the roof is it an easy upgrade just conecting the two panels into just one and then down to my 30amp solar regulator thankyou for any advice
Adding extra solar panels
- Thread starter Plug
- Start date
I have limited experience with solar, but from an electrical perspective ......
300W at 12V works out at 25 Amps. Your controller is rated at 30A so that would be OK. I had a quick Google and your battery should be OK charging at 25 Amps (check the manufacturers specification to confirm). My only concern would be the size of the cable from the existing panel to the controller, and from the controller to the battery. It would have been designed to carry 8.3 Amps and may not be capable of carrying 25 Amps without overheating.
300W at 12V works out at 25 Amps. Your controller is rated at 30A so that would be OK. I had a quick Google and your battery should be OK charging at 25 Amps (check the manufacturers specification to confirm). My only concern would be the size of the cable from the existing panel to the controller, and from the controller to the battery. It would have been designed to carry 8.3 Amps and may not be capable of carrying 25 Amps without overheating.
You will need more professional advice, but I am sure it will work fine when you have the answers. I believe it is both possible to wire in parallel or in series and there are pro’s and cons which also depends on the type of controller. And how the panels mix. I did the same in 2016, but cannot remember the details.
If you are to buy your new panels from a specialist you may well get some good advice thrown in fot free.
When I installed my panels, I used semi flexible ones glued down. Which saved a fair bit of weight.
John
If you are to buy your new panels from a specialist you may well get some good advice thrown in fot free.
When I installed my panels, I used semi flexible ones glued down. Which saved a fair bit of weight.
John
You need a 100 watt panel to match your existing 100 watt panel, you will see no advantage by fitting a 200 watt panel to a 100 watt panel, you will only see 200 watts. Wire your panels up in series with a Victron MPPT solar controller 75/15.
Or alternatively disconnect your existing 100 watt panel and fit 2 x 130 watt flexible solar panels in series with a Victron MPPT 100/20 controller
Thankyou for all the advice i have a truma MPPT solar controller fitted i'd have thought that would have been fine and now thinking of just going with like you say have just 2 100w panels .
What do i have to buy to connect the 2 panels into just 1 from my truma one fitted from new
You can buy a male to female cable and connector online probably from your solar panel supplier, ditch the truma controller it pants, wire up your panels in series to a Victron controller (I always add a fuse), I connected my Victron directly the habitation battery (I always add a fuse)
I have 2 x 80 watt solar panels via Victron bluetooth 75/15 solar controller.
I have 2 x 80 watt solar panels via Victron bluetooth 75/15 solar controller.
Thanks for the advice but would the 75/15 victron controler be safe for 2 100w panels just looked on amazon and can get a 75/20 for £65 would that be better and are they ok to use with lithium 110amp batterys i have'nt got the other panel as yet so would only be useing the 100w panel for now
And what wrong with the truma controller ??
100/20 bluetooth will be fine don't forget to adjust your setting for lithium, I added a Victron battery sense to monitor the temperatures, don't charge a lithium below zero degrees C
My lithium battery has built in heater plates so chargeing in low temp is not a problem
Is it easy to change the settings to lithium as getting on a bit and all this tech stuff just goes over my head and would the 75/15 controller be ok when i upgrade to two 100w panels as i dont want to buy one the have to change ltr thankyou again for the advice
Can I Mix 100 Watt and 200 Watt Solar Panels?
Diving into solar power raises many questions, especially when selecting suitable solar panels. One common query is: Can you mix and match 100-watt and 200-watt solar panels? This article addresses this question, providing a clear comparison between 100W and 200W solar panels and guidance on how...
www.bougerv.com
When I linked my panels 8 years ago, I was informed that I could. Mine were well mismatched, one being 100 watt, the other 18. But I followed the advice given at the time and my system worked with an Epever controller, BT and WiFi.
I cannot exactly remember how I did it, so will not attempt to advise. But some googling will say it can be done, though not to be advised.
I feel that this is an expert area.
John
I cannot exactly remember how I did it, so will not attempt to advise. But some googling will say it can be done, though not to be advised.
I feel that this is an expert area.
John
With 200W panel you will rarely see 200W of output only, for couple hours on clear day while sun is overhead. In reality 15A controller will spend most of its time delivering well <15A. Check specs but I suspect 15A is max it will deliver, these controllers are smart and will reduce output to protect themselves.
There are charts on web that will give output for dates and locations on sunny day.
My advice buy 2nd 100w (identical ideally) or jump to new 300W. Lot will depend on age off your caravan and what devices you are running. Old caravans without smart controllers use next to nothing. My 2009 Adria draws 2W during day and most that is gas detector. LED bulbs will reduce nighttime draw.
TVs, laptops, ebike charging are big power consumers.
Mount to solar charger as close as possible to battery with shortest heaviest cable between. Charger measures battery voltage at its output terminals if there is 0.4V drop then charger will see 13.6V (100%)while battery is 13.2V( 70%) and reduce charging current. Will eventually fully charge battery but won't deliver full current over last 30% to do it.
Losses in wires from solar panel to charger aren't that important eg 1V at 10Amp is 10W but in this case panels will be producing 200W so 5% isn't here or there in scheme of things.
Need to mount controller close to battery ie under a bed means BT is essential for remote monitoring.
Place switch in solar panel circuit and another on battery (100A circuit breaker). At home I isolate both and turn on once month on sunny day to topup battery.
.
There are charts on web that will give output for dates and locations on sunny day.
My advice buy 2nd 100w (identical ideally) or jump to new 300W. Lot will depend on age off your caravan and what devices you are running. Old caravans without smart controllers use next to nothing. My 2009 Adria draws 2W during day and most that is gas detector. LED bulbs will reduce nighttime draw.
TVs, laptops, ebike charging are big power consumers.
Mount to solar charger as close as possible to battery with shortest heaviest cable between. Charger measures battery voltage at its output terminals if there is 0.4V drop then charger will see 13.6V (100%)while battery is 13.2V( 70%) and reduce charging current. Will eventually fully charge battery but won't deliver full current over last 30% to do it.
Losses in wires from solar panel to charger aren't that important eg 1V at 10Amp is 10W but in this case panels will be producing 200W so 5% isn't here or there in scheme of things.
Need to mount controller close to battery ie under a bed means BT is essential for remote monitoring.
Place switch in solar panel circuit and another on battery (100A circuit breaker). At home I isolate both and turn on once month on sunny day to topup battery.
.
Thanks for the advice my caravan is a 2022 bailey will find it hard to have the controller near the battery because the battery is shunk into the floor in the middle of the van so theres always gonna be a distance between panel controller and battery thanks for your reply got loads to think about cheers
Fitting the Victron MPPT as close to the battery good advise, however there is nothing stopping you replacing and fitting the Victron MPPT is the same location as your existing Truma controller it will just be slightly less efficient,. The Victron controller is more efficient than your Truma you will not notice a drop in efficiency, especially after you add that extra 100 watt panel in series in the future.
My Victron is in the top locker where the previous controller was. However I have 4mm cable between it and the battery and a Smart Shunt that feeds the controller with the exact battery voltage over VEnet ensuring the correct charge levels.
Is there any advantage in doing this? My solar controller switches to 'maintenance mode' once the battery reaches full charge (I assume that they all do) so it shouldn't be a problem leaving it on all the time. I've tried goggling to see whether occasional recharging or maintenance charging is better for the battery but so far I've come up blank.
I don’t know what the maintenance current is but I would take my caravan battery home and put it on a CTEK charger for periods and always seemed to get good battery life.
How to Store Lithium LiFePO4 Batteries for Long Term
Lithium Ion batteries are the most famous and widely used rechargeable batteries. There are many Lithium-ion batteries, but the most commonly used are the iron phosphate chemical composition known as
www.evlithium.com
Interesting comment above as I have always been told for long term LifePo4 storage 60% -80% is best, in fact all the LifePo4 batteries I have bought were supplied 60% charged.
I turn my solar on and off remotely, it means I'm not constantly charging the LifePo4 battery when away from the van.
I've been suffering withdrawal for the last couple of weeks as the van has been inside at the dealers and I haven't been able to connect to it. I will see what it's like tomorrow.
I turn my solar on and off remotely, it means I'm not constantly charging the LifePo4 battery when away from the van.
I've been suffering withdrawal for the last couple of weeks as the van has been inside at the dealers and I haven't been able to connect to it. I will see what it's like tomorrow.
Facebook
Twitter