Should I get a MPPT controller, or B2B or CTEK or......... help?

Good practice is to place a fuse in an power supply.
 
A proper charger for lead acid batteries should do the bulk of the charge at whatever current rating the charger will give, and when the battery is nearing full charge (at about 13.6v). The voltage should then drift up and do what is called a float charge at 14.4v for several hours to maintain the battery at peak performance. I have never seen more than 13.6 v indicated on my MH screen, so I am not sure it does the proper charging job! Solar panels in the winter will just not give enough output to charge large batteries even with MPPT. Occasionally maybe using a smart charger for each battery makes sense. I use Banner "deep cycle" batteries for the electric car I converted. ( BTW, truck batteries and leisure batteries are not the same!). I used to check the acid levels regularly, but then forgot for many months, well probably at least 24!. Performance started to worsen. Checked levels and found them well down exposing the tops of the plates. Topped them all up and thoroughly charged them. They do not seem to have suffered and everything is back to normal. Well it will be when I get it back on the road again after replacing the motor brushes!
 
nabsim said:
Its nice to be able to isolate the panels if you need to work on anything
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Very true.
Some controllers (such as the Victrons) you can turn off the charger so the outlets are not powered. I have used this feature a few times when redoing the DC supplies but never had a need to isolate the panel inputs.
The place the panels should be fused if wanting to do so would really be outside right at the panel and not adjacent to the controller. (you can get MC4 connector style fuse-holders which would be the best option for most installs using MC4)
 
bjh said:
A proper charger for lead acid batteries should do the bulk of the charge at whatever current rating the charger will give, and when the battery is nearing full charge (at about 13.6v). The voltage should then drift up and do what is called a float charge at 14.4v for several hours to maintain the battery at peak performance. I have never seen more than 13.6 v indicated on my MH screen, so I am not sure it does the proper charging job! Solar panels in the winter will just not give enough output to charge large batteries even with MPPT. Occasionally maybe using a smart charger for each battery makes sense. I use Banner "deep cycle" batteries for the electric car I converted. ( BTW, truck batteries and leisure batteries are not the same!). I used to check the acid levels regularly, but then forgot for many months, well probably at least 24!. Performance started to worsen. Checked levels and found them well down exposing the tops of the plates. Topped them all up and thoroughly charged them. They do not seem to have suffered and everything is back to normal. Well it will be when I get it back on the road again after replacing the motor brushes!
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If you have never seen 13.6V (and no greater than 13.6V has ever occured), then your batteries will not actually be getting a full charge ever! I would suggest this is something worth checking and addressing to try and get your batteries back to full (or at least fuller charge)
 
I received the MPPT controller and solar computer from RoadPro next day and got to grips with the existing setup when I had a bit of free time. Very quick and easy to do, I didn’t bother to cover the panels as it was damp and grey outside. Then I ran the wiring for the display neatly inside a trim panel, and as they say, the job was a goodun.

Then I ran a small cable from the MPPT direct to the engine battery so that it too can receive a small topup charge c.1amp via the panels. I’ve proven that works by putting my voltmeter across the bare end before bolting it on.

As has been said before, there’s negligible power coming out of the panels when it’s cloudy, but when the sun shone the panel showed amps by the bucketful pouring in (that’s a lie, it just dribbled really) so it seems to be working.
 

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SimonM said:
I received the MPPT controller and solar computer from RoadPro next day and got to grips with the existing setup when I had a bit of free time. Very quick and easy to do, I didn’t bother to cover the panels as it was damp and grey outside. Then I ran the wiring for the display neatly inside a trim panel, and as they say, the job was a goodun.

Then I ran a small cable from the MPPT direct to the engine battery so that it too can receive a small topup charge c.1amp via the panels. I’ve proven that works by putting my voltmeter across the bare end before bolting it on.

As has been said before, there’s negligible power coming out of the panels when it’s cloudy, but when the sun shone the panel showed amps by the bucketful pouring in (that’s a lie, it just dribbled really) so it seems to be working.
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Thats the exact same setup I have fitted and it works wonderfully, as you say it feeds 1amp to starter battery to keep it topped up when harvesting. I think Votronic are great bits of kit and I have a 30amp B2B made by them waiting for me to fit when I get the van out. (y)
 
nabsim said:
Thats the exact same setup I have fitted and it works wonderfully, as you say it feeds 1amp to starter battery to keep it topped up when harvesting. I think Votronic are great bits of kit and I have a 30amp B2B made by them waiting for me to fit when I get the van out. (y)
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OK, daft question time now. Why do you need or want a B2B to go with the existing installation you’ve got?

Also, the solar lcd shows what is going into the batteries, but is there something else that can show what exactly is inside them i.e. 80%, 85%, 90% or whatever up to a full charge.
 
SimonM said:
OK, daft question time now. Why do you need or want a B2B to go with the existing installation you’ve got?

Also, the solar lcd shows what is going into the batteries, but is there something else that can show what exactly is inside them i.e. 80%, 85%, 90% or whatever up to a full charge.
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Since around end of October I have not been able to keep up with power consumption, solar does very little and some days nothing at the moment. If I start out with full batteries and keep moving then I am okay but if we attend a meet we are limited with current setup. I looked at different ways of improving this and 'think' I have come up with the best solution for us. I can break in to existing cabling to the Schaudt EBL for Votronic B2B and will only need to add 1 cable from the B2B to the negative on the leisure battery bank. If I had gone down the Ctek route I would have needed to run in bigger cables and fuses all through, the Ctek would have given me 20amp where the Votronic gives me 30amp so I would have needed to fit both Ctek and Smartpass to be sure. My solution may not work for others unless they have same setup though, it is very much bespoke when you look at what you do and one solution certainly does not suit all. If I still struggle after this I will be buying a generator for when I get too low

On the Solar LCD, if you go to Volts it shows what's going to the battery when it is harvesting but when not harvesting it shows wha Volts your leisure battery bank has. If you find a chart to suit your batteries yo can see what percentage is left in by reading off the Volts. I may be wrong but I think all the meters and gauges are only an indication to use to estimate battery/charge state rather thanking spot on, you can use them to see when you need to book a site and recharge if necessary, that's what I do anyway :)

We probably use more power than a lot of users who dont use investors though as we have a compressor fridge and diesel blow heating along with phones, tablets, tv, lights etc just the fridge and heating will put us at least 65 amps a day i 'think'. You may be able to go for a week or more without doing anything. I wouldn't worry about a B2B unless you use your van in winter off sites and find you cant keep up with discharge (y)
 
nabsim said:
investors (y)
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That took a lot of deleting, just to say,

I am not one of Nabs investors.
He’ll say something about predictive text. These retirees?
 
nabsim said:
..... If you find a chart to suit your batteries yo can see what percentage is left in by reading off the Volts. I may be wrong but I think all the meters and gauges are only an indication to use to estimate battery/charge state rather thanking spot on, you can use them to see when you need to book a site and recharge if necessary, that's what I do anyway :)
....
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Yup, you are wrong (in parts) ;)
The charts that translates Voltage to Battery Capacity are only valid where there is no charge going into the battery AND there is no discharge from the battery - and there has not been for a period of time.
When you think of it, that must be the case as a fully charged battery sits at around 12.7V - but if you look at a voltage when the solar is active, you will see a voltage of 13V+ .
To get an decent idea of what charge your battery has left without disconnecting both loads and chargers for around an hour, you need a meter/monitor which will provide you with the SOC - State of Charge
 
OK I think there’s some understanding sinking in now. Kind of.

Firstly, it’s pitch dark outside and so I’ve checked the solar. It’s showing 12.9v and has received 86wh today (I zeroed it first thing this a.m.) it was showing 14.4v and 2a midday. We had a bright and sunny periods days here.

@wildebus - Thank you very informative, albeit a bit pricey but I’ll bear it in mind.

@nabsim - as I understand it, you’re sat in a site depleting your battery because it’s midwinter and no sun, and so the B2B will allow faster charging if you go off for a drive?

My Burstner is also equipped with a Schaudt EBL99 fitted under the passenger seat. The instructions for the solar computer says it’s possible to go from the MPP250 direct to the EBL, which I assume means that will correct the gauge in the hab area? Is it a special lead, or just a length of cable with suitable connectors?
 
@SimonM Yes, I will get charge by running the engine, just running it without the B2B hasn't put enough charge in

Regarding EBL, you would need to check how many amps you can put through the solar input, on my EBL 100-2 I was limited at 15amps so I didn't bother, my display panel is also not the one that would have displayed solar input, mine is the DT100 and you need the 200 I believe

Edit: Sorry missed the bit about cables, you can buy the cable made up I have the part number somewhere, I gave away the one I had as it was no use to me. It is just some cable with the correct connectors though
 
Thanks. I’m not too sure about the EBL and I’m happy enough to look at the solar lcd. I’ll have a look at the B2B to see if it’s something else to want ?
 
SimonM said:
Thanks. I’m not too sure about the EBL and I’m happy enough to look at the solar lcd. I’ll have a look at the B2B to see if it’s something else to want ?
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Better to wait and see if its something you need, if you get what you want you will go bankrupt :)
 
nabsim said:
Better to wait and see if its something you need, if you get what you want you will go bankrupt :)
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Got to spend my hard earned on me you know ?

I went out into the MH mid morning home here, it’s foggy as heck and I can just make out the sun, but it’s not sunny, and when I looked at the LCD it was showing 14.4v and 2a. I then checked the engine battery, as I’ve now got it hooked up to the MPPT and that is also showing 14.4v. Sounds good to me. Perhaps I’ve done right for a change.
 
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