150w Solar Panel enough for 2x Leisure Batteries? (2 Viewers)

[autorouter]

Thanks! I imagine in the evenings we'll be doing the same and I'm keen to see how much % of the battery this uses up! I was just curious as to whether the solar panel on it's own will be enough to charge both batteries but I suppose it'll be a wait-and-see kind of thing.

Just a general point. Your eyes are extremely good at compensating for the variation of light intensity over the course of a day. You don't really notice it getting dark until the sun sets. However if you get a light meter and measure the light intensity over the day, you find a huge variation between mid-day and the morning/evening light.

In winter, the sun is low all the time, and it's more or less permanent morning/evening light. And that's without the thick cloud cover that sometimes goes on for days. I have a 4000W solar array on my house, and some winter days it hardly gives enough to charge a phone. You will be surprised at how little charge you get from your solar panels in winter.

In the winter you will need an additional source of charging. A B2B is the favourite, if you move about a lot. You can always go on a campsite to hook up to mains, or maybe find an aire with a low power hookup. Another possibility is to get a cable that connects a Type2 EV charging point to your mains inlet, to charge your batteries up.

 

[Windy66]

I have 130Ah lithium. Which is more or less equivalent to your 200Ah setup. I also have 200w on the roof solar and it’s not enough except in summer and autumn. 500w would probably work though.

 

[Jolly Jack Tar]

Also if one battery is much older it will pull the new one down to its level

As an ex Navy guy with 4 years on diesel/electric battery submarines I would advise matched batteries of the same capacity and age.You will have overcharge/undercharge issues otherwise...our lives depended on battery power in submarine silent running configuration so understanding of the principles was our bread and butter!

 

[ChrisL]

As an ex Navy guy with 4 years on diesel/electric battery submarines I would advise matched batteries of the same capacity and age.You will have overcharge/undercharge issues otherwise...our lives depended on battery power in submarine silent running configuration so understanding of the principles was our bread and butter!

If it's not a secret are our submarines now running on Lifepo4 batteries or still a lead acid variant?

 

[slowdriver]

I have just upgraded from 150ah AGM (lead) battery to a 300 ah lithium battery which has allowed us to go from three nights off-grid to seven without starting the engine or going for a run. We are light users in general - just the lights, the fan for the diesel heater, charging laptops/ipad/phones but also running a compressor fridge. I have 200 watts of solar to keep the battery topped up. This works in the summer. In winter I'd expect the effective period off-grid to drop back to between 3 and four days. We shopped around for our lithium upgrade and got excellent advice, a good deal, and a solid installation from OffGrid Power in Wantage. They also provide a 10% discount to MHF members. Depending on your electrical set-up, you may, if you decide to upgrade to a single lithium battery, need to replace the solar charge controller and the B2B. Many modern(ish) vans have a configurable controllers that obviates the need to replace them.

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[ChrisL]

I have 230ah lithium and 250w solar, I use about 30ah a day and already (11:45 am) am back to 96% with a partially overcast sky, if it was sunny it would be back at 100% SOC by now, once it is full again the solar will just be covering whatever load is on the system, charging tablet, phone etc. I've yet to experience a winter with this setup but I'm sure it will perform well into Autumn if the weather is reasonable.

 

[oldiesontour]

320ah lipo4 , 640w solar ,50amp B2B with mppt , total cost under £900.
Great in summer ,but solar almost useless in winter (UK)

 

[Lenny HB]

Just used our new van for the first time since installing lithium.
460 ah lithium actually coming up at 485ah with 350 watts of solar.
6 nights we are down to 34% battery power, fridge running on gas, using electric kettle and used the air fryer twice & put a 50% charge into one of the bikes TV used one night for 2 hours. Drove yesterday for 50min but only have a 25amp B2B until I wire in another one.
Not fitted a remote switch on the inverter yet so that is taking over 30ah a day in standby.

 

[Katies-travels]

Hi all,

Looking to get a bit of advice/guidance here. We'll be picking up our first motorhome soon and have opted to have an additional leisure battery installed, as we're wanting to camp off grid as much as possible. The factory battery is 95Ah and the additional battery will be 105Ah, I imagine we'll mainly be charging up batteries of laptops/camera/drone in the evenings (not all at once mind!). I've got absolutely zero experience with power and batteries so just wanted to check we'd be alright with this set up for what we'll be using power for.

Any hints or tips are greatly appreciated!

Thanks

If you are adding another battery it must be same type and ideally make

 

[Jolly Jack Tar]

If it's not a secret are our submarines now running on Lifepo4 batteries or still a lead acid variant?

lead acid to SG1275 in my day.....

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[headlight]

Just used our new van for the first time since installing lithium.
460 ah lithium actually coming up at 485ah with 350 watts of solar.
6 nights we are down to 34% battery power, fridge running on gas, using electric kettle and used the air fryer twice & put a 50% charge into one of the bikes TV used one night for 2 hours. Drove yesterday for 50min but only have a 25amp B2B until I wire in another one.
Not fitted a remote switch on the inverter yet so that is taking over 30ah a day in standby.

Your inverter takes 30AH a day or 1.25 amps per hour on standby Lenny ?
My 2,000 watt inverter takes 0.1 amps per hour or 2.4 amps per day on standby.
Because the drain is so low I haven't bothered fitting an isolator switch to it.

 

[cyberyacht]

34% equates to 270AH over six days=45Ah pd. which isn't a lot after your inverter's appetite. I'd have thought your panels would have put a bit more in than is apparent from your figures. Perhaps you brew up more often than me.

 

[Guigsy]

Just used our new van for the first time since installing lithium.
460 ah lithium actually coming up at 485ah with 350 watts of solar.
6 nights we are down to 34% battery power, fridge running on gas, using electric kettle and used the air fryer twice & put a 50% charge into one of the bikes TV used one night for 2 hours. Drove yesterday for 50min but only have a 25amp B2B until I wire in another one.
Not fitted a remote switch on the inverter yet so that is taking over 30ah a day in standby.

So if you sorted the remote, you'd be fine without the B2B?

You're still using about 4 times what I go through.

 

[Lenny HB]

So if you sorted the remote, you'd be fine without the B2B?

You're still using about 4 times what I go through.

First. Night 108ah

 

[Don Campbell]

Thanks Guigsy I'll have a more detailed look into this, would you recommend anyone to install this if we did go down this rout

I wonder why you have gone for 150w instead of a 300w panel which would fit on your roof or even more. The extra cost of a 300w over a 150w is insignificant given the installation costs are the same for both systems. With a 3 way fridge and propane for winter heating you should be fine. We have a similar system and we watch a few hours TV each evening. With 300w as long as it's not totally grey all day we are charged by midday in winter and in summer by about 8 or 9am.

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[BattyBurke#1]

Cheers, we'll be full-timing (constantly moving around) and the fridge is 3-way. We'll have two 11kg gas cannisters (plus Gaslow for EU) in addition to the solar. It might be something we just have to go with and see how we get on, I guess it's not a huge issue to install an additional solar panel if we find ourselve struggling to charge the batteries in autumn/winter.

In general, system capacity issues are not on the storage side, but rather, on the source side. Unless your solar panels are providing all the energy you need to run everything during the day AND to charge your battery bank enough to get through the night you'll have issues. DC-DC charging will help as long as you are driving every day.

 

[Guigsy]

In general, system capacity issues are not on the storage side, but rather, on the source side. Unless your solar panels are providing all the energy you need to run everything during the day AND to charge your battery bank enough to get through the night you'll have issues. DC-DC charging will help as long as you are driving every day.

Depends on your strategy. I have a lot of storage for the amount of energy I use each day. But a modest B2B and solar setup. If it's been dull for a few days and I've not driven much, I expect my charge to drop over a few days. But I've never got close to running out of charge over three weeks. By which point I'm either home, or I've gone to a site with hookup for a down day. It means I'm not having to move on because there's not enough sunshine. I had to break the mentality that I had to reach 100% every day.

 

[headlight]

I have 230 watts solar, 230AH LifePo4 and a 60amp B2B.
I never go on hook up.
In winter solar can be virtually zero but I have enough battery capacity to do 4 days stationary with no charge input before needing to move to let the B2B charge the battery.

 

[Richard n Ann]

We've just got 1 x 80ah gel battery, compressor fridge and 150w solar. Battery went down to 75% this morning, (maybe lower but I saw it at 75%)

No TV though which helps, and don't use the van in winter although I made the panel tiltable if necessary and that makes a massive difference when the sun gets lower in October.

 

[MichaelT]

First. Night 108ah

Is your inverter running the fridge like mine or did you find out how to stop that without turning it to run on gas?

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[Lenny HB]

Is your inverter running the fridge like mine or did you find out how to stop that without turning it to run on gas?

Switching it manually if inverter is on got a few other things to do before I try and find that connection. It's on the same circuit as the kitchen socket.

 

[MichaelT]

Switching it manually if inverter is on got a few other things to do before I try and find that connection. It's on the same circuit as the kitchen socket.

Whi h is the socket you want most for the inverter

 

[breeks]

I just use a generator fantastic

 

[Jonny193]

Hi all, just revisiting this with a follow up query. With 2 leisure batteries installed is it possible to link these to a B2B charger alongside the solar panel? We'll be on the road every 1 or 2 days driving so it might be that a B2B charger linked up to our pre-installed leisure batteries would do the job nicely.

 

[headlight]

Hi all, just revisiting this with a follow up query. With 2 leisure batteries installed is it possible to link these to a B2B charger alongside the solar panel? We'll be on the road every 1 or 2 days driving so it might be that a B2B charger linked up to our pre-installed leisure batteries would do the job nicely.

Yes

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[Jonny193]

Yes

Nice one, thanks. That could be a reasonable solution then if we get out and find we're short on charge!

 

[dunnah01]

Hi all, just revisiting this with a follow up query. With 2 leisure batteries installed is it possible to link these to a B2B charger alongside the solar panel? We'll be on the road every 1 or 2 days driving so it might be that a B2B charger linked up to our pre-installed leisure batteries would do the job nicely.

If you're not too heavy a user and moving every day or two then you may not even need a B2B. The standard split charge may be sufficient. Why not just try it as is and see if you need to upgrade anything or not.

 

[Jonny193]

If you're not too heavy a user and moving every day or two then you may not even need a B2B. The standard split charge may be sufficient. Why not just try it as is and see if you need to upgrade anything or not.

Yeah we'll do just that, see how it goes but I'll keep this in the back of my mind in case we do need to explore options. Thank you

 

[headlight]

Yeah we'll do just that, see how it goes but I'll keep this in the back of my mind in case we do need to explore options. Thank you

The split charge on my Swift only gave a measly 12 amps to my leisure batteries.
I replaced it with a 60 amp B2B.
On my sister's Elddis her split charge gives a more respectable 25 amps.