Campervan electrics issues

[Rob1960]

Hi. I wonder if anyone can help. I have a T5 fitted with a 70Ah leisure battery. I don't have a hook-up but rely on a 100W solar panel which delivers 5.35Ah at Pmax via a solar controller. The only electrical device I use is an Isotherm fridge which is 72 W and draws 6Ah off a 12v battery. I turn the fridge off overnight but have 2 issues. If I turn the fridge on when the engine isn't running, the van electrics go totally dead. They will only come back to life when I run the engine for a period. I have also noticed that if I leave the van during the day with the fridge running, I sometimes get back and same thing - electrics totally dead, even when van is parked in full sun. Clearly my panel is not generating enough power but surely the leisure battery should have enough in reserve to keep the fridge going during the day when supplemented by the panel? Also, what is happening here? There is no cutout in the system. Is the battery somehow shutting itself down? If so, this can't be doing the battery any good.

Any suggestions? For example, can I buy a standalone solar panel to plug into the 12v socket and supplement the roof mounted panel during the day?
Thanks, Rob

 

[MisterB]

Yes you can increase the solar which would help. Put the biggest you can fit as then when there's not a lot of 'sun' you can harvest as much as you can. Cheapest option is prob a pre used domestic panel but you will prob need to change your solar controller to a bigger one.
You could also think about increasing your battery capacity or changing to lithium (at a cost of course)

 

[tonyidle]

TBH I don't think there's any chance of running a 6 amp constant load from your system. 6 amps for, say, 10 hours is 60 Ah. Your battery is nominally 70Ah of which around 50% is usable if you want it last. You need a battery at least twice that size, as much solar as will fit on the roof, and a battery to battery charger for use when the van is moving. Even then during a period of little sun you'll only manage a couple of days off hook-up. It is likely, given your use, that the battery requires replacement anyway.

 

[rod_vw]

It sounds to me that your leisure battery is dying. I have run T5s & a T6 for a good number of years with 100W Solar (albeit with twin leisure batteries) and a Waeco fridge but never had the problems that you describe.

May I suggest that your question would be better placed on the T6 Forum or the T4 T5 Forum for a knowledgeable answer.

 

[rod_vw]

TBH I don't think there's any chance of running a 6 amp constant load from your system. 6 amps for, say, 10 hours is 60 Ah. Your battery is nominally 70Ah of which around 50% is usable if you want it last. You need a battery at least twice that size, as much solar as will fit on the roof, and a battery to battery charger for use when the van is moving. Even then during a period of little sun you'll only manage a couple of days off hook-up. It is likely, given your use, that the battery requires replacement anyway.

The Isotherm fridge will not be pulling that current continuously, probably even in current UK temperatures I doubt it will be as much as 50% of the day and the OP says that he switches it off at night.

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[autorouter]

I think you are a bit optimistic about the yield of the solar panel. If it's flat on the roof, ie not tilted like on a house roof, then you'll only be getting at most 80% of the nominal 100W power. Also you'll probably have a PWM type solar controller, which controls the panel power as it goes into the battery. That means you're probably only getting 5A at most going into the battery, and the fridge is taking 6A out. The solar can't keep up, so the battery gradually loses charge.

For example, can I buy a standalone solar panel to plug into the 12v socket and supplement the roof mounted panel during the day?

A solar panel needs a solar controller, and the output of the solar controller goes into the 12V socket to charge the battery. A solar panel is at least 18V, and some of them are nearer 40V. It would overcharge and damage a battery without a solar controller.

I think it's not possible to run a fridge from the battery without at least 200W of solar panels, and a good solar controller. Usually 300W is recommended to give some margin. An extra 100W of panel would be the minimum, I think, and choose an MPPT type solar controller instead of a PWM type. An MPPT gets more power from the panel when it's cloudy or the light is not as strong, so it is better in the morning and evening. And maybe double your battery capacity to give you a chance to last longer if it's not very sunny.

 

[Rob1960]

TBH I don't think there's any chance of running a 6 amp constant load from your system. 6 amps for, say, 10 hours is 60 Ah. Your battery is nominally 70Ah of which around 50% is usable if you want it last. You need a battery at least twice that size, as much solar as will fit on the roof, and a battery to battery charger for use when the van is moving. Even then during a period of little sun you'll only manage a couple of days off hook-up. It is likely, given your use, that the battery requires replacement anyway.

Thanks Tony. That's good advice. The problem in my T5 conversion is space - no room for a bigger battery and certainly not for a second one. Agree about the battery probably needing replacement - I think I've overloaded it!

 

[autorouter]

The problem in my T5 conversion is space - no room for a bigger battery and certainly not for a second one. Agree about the battery probably needing replacement - I think I've overloaded it!

Having limited space, a lithium battery is a very good idea. You can probably fit a lithium battery of at least twice the capacity into the same space. Not only that, but you'll be able to use 80% to 90% of the capacity without problems, compared to about 50% for a lead-acid type. So a big increase is usable capacity.

Another advantage of lithium is it doesn't deteriorate if left for a long time without charging to 100% regularly. I imagine that probably happened to the existing battery, it's not easy to get to 100% without hookup or lots of solar.

Of course a lithium battery is quite an expensive outlay, and also you may need a B2B (DC-DC charger) in place of the existing split charge relay, but it's worth considering.

 

[rod_vw]

Thanks Tony. That's good advice. The problem in my T5 conversion is space - no room for a bigger battery and certainly not for a second one. Agree about the battery probably needing replacement - I think I've overloaded it!

Rob1960 I don't know where your leisure battery is located but unless there is a lot of extras under seats it is possible to get one under each front seat. The genuine VW 2nd battery is under the left seat which is where I have some extra fitments but there is similar space under the right one. height of the battery is governed by the type of swivel (if you have one) that is fitted to the seats. My T6 is a LWB so my 2nd battery is located in the furniture with ease. This van is for sale now and there is a link to pictures of it in my signature below.

 

[Hoovie]

Thanks Tony. That's good advice. The problem in my T5 conversion is space - no room for a bigger battery and certainly not for a second one. Agree about the battery probably needing replacement - I think I've overloaded it!

if you want to use the space wisely, there is plently of room
I updated the electrics of a T6 Kombi a few years ago. Fitted 200Ah (2 x 100) of AGM Batteries, 30A B2B and a 1500W Inverter, plus a Victron BMV-712 and a Isolation switch - all under the front two seats.
Quite a few people have installed a single 160Ah battery in a T5/T6 seat base. needed some trimming of seatbase metalwork, but it is certainly doable.

Probably have knackered the existing battery. But get another the same and the same thing will just happen again.

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[rod_vw]

Roamer supply a 230Ah Lithium that will fit under a T5/T6 seat base.

 

[Rob1960]

I take the point about a lithium battery. I will certainly investigate that option. From the previous responses I got the message that you cannot simply plug an extra solar panel into the 12v socket to boost the battery charge. Is it possible to wire an additional standalone panel into the existing solar controller, or is it more complicated than this?

 

[rod_vw]

I take the point about a lithium battery. I will certainly investigate that option. From the previous responses I got the message that you cannot simply plug an extra solar panel into the 12v socket to boost the battery charge. Is it possible to wire an additional standalone panel into the existing solar controller, or is it more complicated than this?

You speak of a 12v socket, what do you mean? If you are thinking of the normal OEM sockets on the dash of a T5 then it will be connected to the engine battery (unless the normal wiring has been altered) so that will not charge the leisure battery.
If you have 12v sockets in the habitation area they may or may not be connected to the leisure battery depending no how the converter wired your vehicle. I always connect all circuits in the habitation area to the leisure batteries except for the OEM interior lights. That way I have dual supply for basic lighting just in case something goes wrong with 12v supply.
Ideally solar panels should be controlled by a MPPT controller for greatest efficiency and adding extra panel(s) is not as simple as just connecting to the controller.

 

[autorouter]

Is it possible to wire an additional standalone panel into the existing solar controller, or is it more complicated than this?

Solar controllers are chosen by their output amps, which tells you the maximum power of panel that should be connected. A 10A controller feeding a 12V battery can control up to 10 x 12 = 120W of solar panels. I think it's likely that the existing solar controller is just big enough to take your existing panel, and wiring an extra panel to it would probably be too much.

You could get a new solar panel, plus a controller to go with it, and wire its output to a 12V socket, or direct to the battery if you prefer. The two solar controllers connected to one battery would be OK, they would both charge the battery. An MPPT type is better than a PWM type, if you have the choice.

 

[Rob1960]

Thanks for this. To avoid the bother of fitting a new battery, panel and solar controller to the van, I am pondering a simpler solution. This involves buying a Jackery portable power station (Li battery with built in controller) and 100w standalone solar panel. I already have a Noco Genius smart charger attached to my leisure battery so would plug in the charger to the Jackery to supplement the charge coming from my rooftop panel and top up the leisure battery when needed. The people at Jackery seemed to think this would work.

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[MisterB]

Thanks for this. To avoid the bother of fitting a new battery, panel and solar controller to the van, I am pondering a simpler solution. This involves buying a Jackery portable power station (Li battery with built in controller) and 100w standalone solar panel. I already have a Noco Genius smart charger attached to my leisure battery so would plug in the charger to the Jackery to supplement the charge coming from my rooftop panel and top up the leisure battery when needed. The people at Jackery seemed to think this would work.

I'm not surprised they are suggesting it might work, but at what cost compared to fitting a lithium battery? Power stations have their benefits, but for me a properly thought out and well planned permanent install wins hands down.

 

[Rob1960]

Oddly, the cost of the Jackery power station which is essentially a Li battery, plus the standalone panel comes in at just over £400 - about the same as buying a new Li battery!

 

[MisterB]

For a comparable amount of Ah ? That does surprise me to be honest but I'm sure you've done the sums and comparisons.

 

[Hoovie]

For a comparable amount of Ah ? That does surprise me to be honest but I'm sure you've done the sums and comparisons.

Think we know the answer to that, TBH

 

[urban_biker]

The Jackery explorer 2000, that costs £2k is 2160Wh. My Fogstar drift 300AH lithium is 3600wh and cost £900ish. Admittendly the Jackery includes an inverter and solar controller etc.

I think these set-ups are ideal for tent camping but in a motorhome you are much better having a decent leisure battery, unless you need remote power a distance away from the van for some reason.

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[Hoovie]

The Jackery explorer 2000, that costs £2k is 2160Wh. My Fogstar drift 300AH lithium is 3600wh and cost £900ish. Admittendly the Jackery includes an inverter and solar controller etc.

I think these set-ups are ideal for tent camping but in a motorhome you are much better having a decent leisure battery, unless you need remote power a distance away from the van for some reason.

There is a very nice (IMO) Power Station setup that I have had my eye on and contemplated buying. If I was still doing van electric conversions and updates/installs I would have bought it to have Power where I needed it on vans I am working on, but for my own Motorhome leisure use, they really are suitable for those who don't intend keeping their van for much longer or have very limited space for installing (maybe small campers where a driveaway awning is a key part of the setup?). For a fully fledged motorhome, a permanent Battery + Inverter install is much more cost effective.

The one I was looking at (and still might get as could be useful as a backup for powercuts and garden use!) is the VTOMAN Jump 1500X plus additional Jump 1500 Extension Battery.
For £1100 you get a 1500W PSW Inverter (1500W continuous, not peak, note) plus a total of 2376Wh of LiFePO4 Battery (that is 185Ah of Lithium Battery!) in a very portable setup. The only downside of that system is it is a slow charge compared to something like the Ecoflow.

(EDIT: after typing this, decided to stop ummng and ahhing and bought the kit! super price for the battery capacity and inverter size in a portable setup and I had already decided I didn't need the fast charging ability. Overnight recharge is fine).

 

[urban_biker]

There is a very nice (IMO) Power Station setup that I have had my eye on and contemplated buying. If I was still doing van electric conversions and updates/installs I would have bought it to have Power where I needed it on vans I am working on, but for my own Motorhome leisure use, they really are suitable for those who don't intend keeping their van for much longer or have very limited space for installing (maybe small campers where a driveaway awning is a key part of the setup?). For a fully fledged motorhome, a permanent Battery + Inverter install is much more cost effective.

The one I was looking at (and still might get as could be useful as a backup for powercuts and garden use!) is the VTOMAN Jump 1500X plus additional Jump 1500 Extension Battery.
For £1100 you get a 1500W PSW Inverter (1500W continuous, not peak, note) plus a total of 2376Wh of LiFePO4 Battery (that is 185Ah of Lithium Battery!) in a very portable setup. The only downside of that system is it is a slow charge compared to something like the Ecoflow.

That sounds like a pretty good price for what you get. They do give you more flexibility.

 

[Hoovie]

That sounds like a pretty good price for what you get. They do give you more flexibility.

It seemed to me the best deal of all the various power stations around when I was looking. I have nearly bought it every week for the lst 2 months!
Missing out on the Phone app control of the Ecoflow, which would be nice (I love gadgets ) but is it needed? not really. I think Fast Charging - or the lack of with the VTOMAN - could be a major downside for some users, but I can't see that being a problem for me personally, but I have no doubt some others would be different.
The 1500W inverter is a significant feature and is bigger and more capable then most Power Stations of a similar capacity.