More solar or

I have 100w of solar on the van and was going to put up another 100w but now I'm thinking of a battery to battery charger instead as this would work in the winter ,is this a good or bad plan ?

Just remember that the engine must be running for the B2B charger to work. Not much use if you are parked on a site for a few days. If you are moving a lot, they seem great. My engine charges the leisure batteries, I have no idea how though. Wouldn’t imagine it is a B2B charger, but still does the job on a journey

I’m not knocking them, just making a point. By on site I didn’t necessarily mean a campsite. Think vantastival. Not everyone be happy running your engine beside them either, especially in France. Horses for courses I suppose. Be good to have them all I suppose. Best of all worlds

I could be wrong, but I think the power that Dave is looking for won't be got by one more panel in the winter.

He's a non site Motorhomer and his heating eats batteries. A Generator is next to rubbish for quick charging and who wants to listen to one of them for hours. A B2B and a half hour of engine running every day might be the thing.

Was it always a problem or is it a new phenomenon, maybe there is a different issue, causing the problem. How many leisure batteries have you, and what size

Well that’s ticking all the boxes big Liam, so yes that would be the holy grail for sure. But if you were to add one item, either an extra solar panel or a B2B Charger what would you choose? I don’t think there is a one size fits all answer. A lot depends on what suits you. You could also make an argument for extra battery capacity. So heading off with full charged batteries (via home charging on grid) could buy you an extra couple of nights just because you added another battery. But you might be maxed out on battery power already Dave.

I have purchased the bits needed to connect a third big leisure battery, and only switch it in if original two are low. I haven’t done it yet as haven’t had an issue so far. I suppose that day will come and I’ll be kicking my self

Yes always a problem, I have 2x100w batteries, I think some wireing upgrade would help also but ???

@big LIam I have no faith in AGM batteries I don't think most van charging systems can handle them

I'm aware of that box but it's relatively new (something to do with euro 6 engine's I think ) and not fitted to most Vans ,IMO most Vans are fitted with a charging system that won't support AGM
I have been looking at that box as a b2b for my van as I have a Schaudt charger but I'm not sure of that either

As yours is relatively new you'd probably get away with adding another identical to your own.

95 isn't a lot although interestingly, is it better to have a 95ah battery with 300 watt of solar or 190ah and 200 watt of solar

The first will charge quick but the latter will last longer.

I have been toying with the idea of another 100w panel but this B2B thing may be a better option for my limited use of the van during winter months

I agree, hence my emoji.

But it's interesting, I have three batteries, 3 X 90 ah with 200 watt of solar (which I haven't fitted yet but came of my last van with same batteries), depending on usage where is the line that says more solar less batteries versus less solar more batteries.

It's just too much to work out

Solar and B2B for me, with 3 batteries. I had 200 watt solar but 'acquired' another 100 watt panel, so will have...

300 watt solar, a B2B and 3 x 90AH leisure batteries. Over producing? you bet

I went down on battery amps.
Advice from Tayna batteries.
Went from 2 x 105 amp AGM down to 2 x 80 amp gel ones.
Powered by 200 w solar panels and voltronic MPPT regulator.
Was concerned but they assured me it was better.
After 3 weekends now so far so good.
2000 w inverter boiled the kettle a few times. Microwave once and the boss used the hair dryer Sun morning.
The solar usual
has them charged again on Wed. Obviously if I was away for a week I would go easier on the consumption.
I suppose it's a matter of what works best yourself !!

Interesting that Tayna recommend smaller batteries, presumably because they will reach full charge faster. As I only have space for a 75 Ah under the passenger seat, (acres of space for the second one), maybe it’s a lucky thing. We definitely do not suffer from lack of battery power when away.

I ordered another Varta agm leisure ( identical to what I have )

I'm finding this discussion very interesting as it's something I've been thinking about over the last while.

We have a 100ah sealed lead acid battery in our Van and a 100W solar panel, all linked together with a CBE PC200 charging system and Victron MPPT charge controller which connects to a solar in port in the CBE unit. I have recently bought another identical 100w solar panel to add to the system.

We wouldn't have a huge requirement for power in the van, we charge phones and tablets, run a small Dometic cr 50 compressor fridge and the water pump when required. We have an undermounted lpg tank so water gets heated using a gas boiler. No tv, laptop or anything like that.

We have had this setup for about 4 years and haven't had too much problems, the main one being the draw from the fridge when it gets really hot as the efficiency of the solar panel is effected pretty significantly by the heat, and the fridge is obviously running overtime. We generally try to use EHU as little as possible staying in Aires mostly. Hence buying the second panel.

As we may need a new battery in the near future I had been looking into the possibility of getting two 100ah batteries at that stage, however when we were having the van converted initially I had suggested this and was told that the alternator/charging system/wiring?? wouldn't be able to cope with charging more than about 150ah of batteries (we didn't have solar initially). This seems to be confirmed by an article on the aandncaravanservices site which talks about burnt out relays due to the amount of amps required when additional batteries are added. On most sites, this one included, the general advice is to add more batteries so how are people getting around this issue? Currently we don't get a huge charge boost from driving from place to place unless it's a long drive, is a B2B charger the way to go and could this be incorporated into our current setup or is it stand alone? I obviously don't want to go ripping out the full electrical system as for the most part it works quite well.

My one other small gripe is that while the solar is brilliant at keeping the leisure battery topped up over winter it doesn't charge the starter battery. The starter battery does however charge if the the van is on EHU, does anyone know of any way to get the solar to do this too? It's not a huge problem as we do try to use the van over winter, but sometimes, especially with weather like the last month, it can sit for a while.

For the moment I'm going to add the second panel and see how we get on this summer before biting the bullet on any other changes. It would be great to get more Independence from EHU though. Sorry just realised I rambled on quite a bit

Have a look at one of these when the leasure is charged it switches over to charge the engine battery .
You can also wire it with a switch to allow y oh to give the engine battery a boost if needed you would have to wire it with heaver cabel in order to do this .
I haven't bothered with this function, simple to wire up in the engine comparment with a lead from the leasure battery and a power feed and earth from the engine battery .
Cyrix Battery Combiners from vitron energyy blue solar it's about €50.

To pass charge to the engine battery I have ONE OF THESE installed. The price can vary from €25 to over €35 so it pays to shop around
In my mh the engine battery gets charge when on EHU only, the above unit looks after things when not on ehu and the sun shines.

Would that be a problem?. Once the engine battery falls below the voltage which operates the split charge relay the connection would just drop out.

As an aside, I fitted Philips DRL's last year and when the engine battery reaches the 'running' voltage while on charge, either from an ehu or solar, the DRL's light up for a few minutes until the voltage drops back, this cycle can go on all-day