Solar panels

brian c

Full Member
Posts
114
Likes
136
Now that is interesting. Solar charging lbatts. And when full charging sbatts. My l batts are often full. And s batt on 70 %(. I worry to much about having flat batts ). Am always saying to my better half. Switch that off, Am now lost as to. Solar. Lithium or what. Definitely need B2B I think. David(Wilde) you need to move to Kent. Thank you all for your answers. Suggestions and future answers. Love reading all the forums even though they tend to loose me. (Got lost in Woolworths once as a child ). Cheers, positive thinking. ---- the world 1. -- covid 0. Brian.
 

trevskoda

Full Member
Posts
23,089
Likes
24,274
I have a very simple solar set up on my van and would be interested to hear the opinions of those with more knowledge than me if it is efficient or not. A single panel feeds via controller to the leisure battery which is connected to the starter batteries via a voltage sensitive relay which can operate in both directions ie when either leisure or starter battery reaches the critical voltage the relay trips and connects both together. The tripping voltage seems to be about 13.7v.
Should maily go to les battery and 1amp to starter if using a good mppt regulator.
Volts should rise to 14.4 then drop to standby 13.7 on cycle.
solar duel a.png
 

wildebus

Full Member
Posts
4,035
Likes
4,263
I have a very simple solar set up on my van and would be interested to hear the opinions of those with more knowledge than me if it is efficient or not. A single panel feeds via controller to the leisure battery which is connected to the starter batteries via a voltage sensitive relay which can operate in both directions ie when either leisure or starter battery reaches the critical voltage the relay trips and connects both together. The tripping voltage seems to be about 13.7v.
That is the "classic" VSR setup that is used on many self-conversions.

Works well in keeping the Starter battery maintained alongside the Leisure Battery when on Hookup or using Solar.
What is not so good is that the Batteries (neither Starter or Leisure) are not getting an optimum charge from the Alternator when driving. This is when a B2B - Battery to Battery - Charger is much better. However you do lose that bi-directional connection and you need another way to keep the Starter Battery maintained.

In that case, you can use a simple cable connection (cue the Cornish Pixie with his tedious link to a overpriced heath robinson mott kit) or get a proper Battery Maintainer like a Battery Master or the better (IMO) Ablemail AMT Programmable Maintainer
 

brian c

Full Member
Posts
114
Likes
136
Hi David. I think I am going to have to take a drive up to you ( COVID permitting). And let you see what I have explain what I want. You tell me what I need and ballpark price and work from there. Fed up with the headaches. And I know people are being very helpul. But when they say it’s easy. Just disconnect. Bypass. Alter. They do not always realise what may be easy for them could be very hard/ impossible for others Anyhow. Time to stop being down. Read some more on the forum and cheer up. Brian.
 

wildebus

Full Member
Posts
4,035
Likes
4,263
Hi David. I think I am going to have to take a drive up to you ( COVID permitting). And let you see what I have explain what I want. You tell me what I need and ballpark price and work from there. Fed up with the headaches. And I know people are being very helpul. But when they say it’s easy. Just disconnect. Bypass. Alter. They do not always realise what may be easy for them could be very hard/ impossible for others Anyhow. Time to stop being down. Read some more on the forum and cheer up. Brian.
No Probs. I am really hoping (and fairly confident) that coming up to springtime we will be in the "herd immunity" phase with vaccines and movements will be a lot closer to normal. Who knows about Jan and Feb and what is possible!?
 

chrismilo

Full Member
Posts
735
Likes
706
Polycrystalline better than monocrystaline batteries will charge in low light too with Polycrystalline better for our UK climate mppt controller too
 

Steveh2010

Full Member
Posts
2
Likes
2
Hi all. What’s the opinions on solar panels. Already have a 150 w. Panel. Thinking of adding two more
See attached. Cheers brian
View attachment 89330View attachment 89331View attachment 89330
I added two LiFePo (100ah each) to replace the existing lead acid; can't believe the difference. With a 100W panel, even in bright sun during the summer, and an electric fridge the old batteries would run down over 2 to 3 days. With the new ones the drop overnight was negligible and they were normally back at 100% by morning coffee. So another thing to consider; extra panels or better batteries?
 

Brockley

Full Member
Posts
14
Likes
7
Hi all, I have a 150 watt solar panel, a Victron 75/15 mppt controller and two brand new 100ah Lucas leisure batteries wired in parallel. As you can imagine, last few weeks has taxed this set up to the extent I need to bring along a power pack just to use the tv! The problem is compounded because we keep the camper on a farm with no hook up and so have to rely on solar charging and not very long drives!

I have a spare 80 watt ‘Enjoy Solar’ panel with the following spec: Volts P. Max 19, Current P. Max 4.12, Open Circuit Voltage 23 and Short Circuit Current 4.57.

I’ve attached a photo of the underside of the existing 150 watt panel. I’ve made a tilting mount for the 80watt panel and would like to join them in parallel. My question is will they be compatible without the larger one frying the smaller one or the Victron controller?

The combined short circuit current is 13.67 amps, this looks like the only figure likely to come close to the maximum capacity of the controller which I’m assuming is 15 amps?

I’d also like to pose another question. We are thinking of eventually changing to a Lifepo4 system and wondered how it might affect the insurance, is it just a case of phoning them and what about certification of the batteries, I know people here buy in from China, but when I asked one seller, they couldn’t provide any international conformity certification so I’ve held back.

Thanks in advance.
5C7669F5-16B9-4ABD-A146-DFD314B7042D.jpeg
 

mfw

Full Member
Posts
1,359
Likes
1,735
Hi all, I have a 150 watt solar panel, a Victron 75/15 mppt controller and two brand new 100ah Lucas leisure batteries wired in parallel. As you can imagine, last few weeks has taxed this set up to the extent I need to bring along a power pack just to use the tv! The problem is compounded because we keep the camper on a farm with no hook up and so have to rely on solar charging and not very long drives!

I have a spare 80 watt ‘Enjoy Solar’ panel with the following spec: Volts P. Max 19, Current P. Max 4.12, Open Circuit Voltage 23 and Short Circuit Current 4.57.

I’ve attached a photo of the underside of the existing 150 watt panel. I’ve made a tilting mount for the 80watt panel and would like to join them in parallel. My question is will they be compatible without the larger one frying the smaller one or the Victron controller?

The combined short circuit current is 13.67 amps, this looks like the only figure likely to come close to the maximum capacity of the controller which I’m assuming is 15 amps?

I’d also like to pose another question. We are thinking of eventually changing to a Lifepo4 system and wondered how it might affect the insurance, is it just a case of phoning them and what about certification of the batteries, I know people here buy in from China, but when I asked one seller, they couldn’t provide any international conformity certification so I’ve held back.

Thanks in advance.View attachment 90299
If you are stuck on farm would you not be better with a cheap generator
 

Brockley

Full Member
Posts
14
Likes
7
Thanks for the thought, I do have a Honda EU22i generator but would prefer a system that can be charged in a couple of hours running the genny or driving rather than all day charging and besides, I’m planning a longer trip (hopefully post covid) and just don’t want to be bothered about battery management any longer and would prefer the garage space for other things.

Any help about the issues mentioned above would be greatly appreciated.
 
Last edited:

mfw

Full Member
Posts
1,359
Likes
1,735
Thanks for the thought, I do have a Honda EU22i generator but would prefer a system that can be charged in a couple of hours running the genny of driving rather than all day and besides all that, I’m planning a longer trip (hopefully post covid) and just don’t want to be bothered about battery management any longer and would prefer the garage space for other things.

Any help about the issues mentioned above would be greatly appreciated.
If you head to sunnier climate you should be able to hold your own - here if you could find a portable wind generator you would probably get through at this time of year
 

trevskoda

Full Member
Posts
23,089
Likes
24,274
Im holding up with 200w of panels and two 90ah batteries, never had a flat battery, voltage this morning 13.7 and its dullish weather.
 

Brockley

Full Member
Posts
14
Likes
7
Our van is rather energy hungry, I’m glad yours is holding up, but can anyone help me with the questions I’ve posed? Thanks.
 

Philip Tomlinson

Administrator
Posts
5,258
Likes
11,763
Hi all, I have a 150 watt solar panel, a Victron 75/15 mppt controller and two brand new 100ah Lucas leisure batteries wired in parallel. As you can imagine, last few weeks has taxed this set up to the extent I need to bring along a power pack just to use the tv! The problem is compounded because we keep the camper on a farm with no hook up and so have to rely on solar charging and not very long drives!

I have a spare 80 watt ‘Enjoy Solar’ panel with the following spec: Volts P. Max 19, Current P. Max 4.12, Open Circuit Voltage 23 and Short Circuit Current 4.57.

I’ve attached a photo of the underside of the existing 150 watt panel. I’ve made a tilting mount for the 80watt panel and would like to join them in parallel. My question is will they be compatible without the larger one frying the smaller one or the Victron controller?

The combined short circuit current is 13.67 amps, this looks like the only figure likely to come close to the maximum capacity of the controller which I’m assuming is 15 amps?
Yes, you can connect them in parallel, the output will be approx the lowest panel voltage times the combined current.

I’d also like to pose another question. We are thinking of eventually changing to a Lifepo4 system and wondered how it might affect the insurance, is it just a case of phoning them and what about certification of the batteries, I know people here buy in from China, but when I asked one seller, they couldn’t provide any international conformity certification so I’ve held back.

Thanks in advance.
Changing to LiFePO4 batteries will give you a more efficient system but if you are still relying on the same solar setup it won't make much difference as you still need the energy from the solar to charge the batteries.

You could get a battery charger with a 50A output and run that from your generator for faster recharge times, or fit a battery to a battery charger to increase the charge rate whilst the engine is running.

The batteries that I have coming from China are from Basen and their batteries have both CE and UR certification.
 

Brockley

Full Member
Posts
14
Likes
7
Thanks Phil, because the two Lucas leisure batteries are new, I’ll link the 80 watt to the 150 watt panel. Hopefully the extra umph will get me through the next couple of months. I’ll be mounting the 80 watt panel on a tilt and lock frame so that should increase efficiency. I have noticed an improvement in changing through the victron mppt controller. Some dull days I’m actually getting absorption and float charge into the batteries instead of bulk alone.

I’ll pick your brains nearer the time I want to take the plunge and change over to Lifepo4. Cheers.
 

rugbyken

Full Member
Posts
1,773
Likes
2,356
hope you’ve not offered more than me jeff guardian of the purse has said i can look at lithium so i’m checking now saw that ad & also followed links to these seem to be plenty of variety but no prices shown ?
 
Top