Cheap 50W Panel Test - Ongoing

[wildebus]

Not sure about some of this, my 30amp B2B seems to work great with my 200ah lifepo4. What you put would say I should have greater than 60ah or am I reading it wrongly (quite possibly)?

Hi,
no, not saying it won't work fine. Just saying that if you wanted as efficient (aka fast) system as possible, you would want a bigger charger (a 200Ah Lead Acid battery bank could accept up to 40-50A, a 200Ah LifePO4 could maybe accept up to 100A (BMS depending), so a charging system limited to 30A maximum is not optimal in terms of efficiency (the typical AGM battery can be charged at upto 20-25% - so 25A per 100Ah; Plain Wet Cell is maybe 10-15%, LiFePO4 varies by BMS but is often around 50% - so 50A per 100Ah).
Doesn't mean it doesn't work great, just means you could get a faster charge with a bigger B2B. Whether that extra speed is needed is another question entirely
(the same is invariably true of most peoples Solar/PV setup, but in that case, it is usually a limit imposed by roof real estate space).

 

[wildebus]

So 3 x Bosch 110 AH LB and 1 x 160AH LEOCH AGM
Checked them on tech data sheets and charge rates are similar so won't be an issue in set up
Alternator, no idea, Van at garage. All brakes needed doing and one front ball joint

The B2B I am thinking might be a better investment as would move it to a newer van if and when that happens rather than a VSR which I would probably just leave in the Van when I sell her. Also I am wondering if with 4 LB's in the Van I should maybe swap it all round to a 24V System as you once suggested ?
Cheers, Robert

What I prefer to do is cable up with nice fat cables suitable for the potential peak of a VSR but leave room for the space a B2B takes . Then whichever you use - VSR or B2B - you are ready for, so it is an easy change over/upgrade.
For someone who wants all-year use and wants off-grid camping, the best split-charge possible is what is needed as that is the sole usable charging system available (as you want to avoid having to get the genny out). If someone is a summer Camper, then Solar is maybe the key? For a campsite camper who plugs in everynight, I would say spend the minimum on split-charge and forget solar.

 

[Nabsim]

Yeah I went for a happy medium, I dont need to put 100 amps an hour in and as you say when you start going up in size the prices need health warnings lol

I would think carefully about no fitting solar, my 300W isn't replacing all my power useage but its getting close now. My battery bank was back at 80% after the light went today. Dont think I have run the genny since Wednesday and I use 65 amps per 24 hours. Of course if you are moving every day then its a different matter but I wouldn't run my engine for power unless its an emergency otherwise.

 

[RAW]

my 30amp B2B

Which one do you have please ??
TIA

 

[RAW]

For someone who wants all-year use and wants off-grid camping, the best split-charge possible is what is needed as that is the sole usable charging system available (as you want to avoid having to get the genny out). I

My plan on Van(s) is to make this new Merc suitable for all year round use. I want to upgrade the Solar but as folk have said putting Flexi on the roof may not be the best option. That is why I think a visit out to you @wildebus might be the best option so we can have a face-to-face and talk about options for the new Merc. However, now that will probably have to be post all this Coronavirus thing, so may not be until Summer / Autumn now, sadly. Unless you fancy meeting up before that is....

 

[wildebus]

My plan on Van(s) is to make this new Merc suitable for all year round use. I want to upgrade the Solar but as folk have said putting Flexi on the roof may not be the best option. That is why I think a visit out to you @wildebus might be the best option so we can have a face-to-face and talk about options for the new Merc. However, now that will probably have to be post all this Coronavirus thing, so may not be until Summer / Autumn now, sadly. Unless you fancy meeting up before that is....

Best to wait until the next phase of the Coronavirus fighting plan - getting out and about for anyone who feels healthy - comes into play (so around 3 months) for any meetups

 

[Nabsim]

Which one do you have please ??
TIA

This is the one I have fitted, very pleased with it

VOTRONIC - VCC 1212-30

Innovative Elektronik für den mobilen Einsatz

www.votronic.de

 

[Nabsim]

Well even better today, its been a bright and somewhat sunny, if cold, day here today. I checked batterys at 4 this afternoon and they were at 87%. Thats 7% higher than they were when the sun went down yesterday so it is already producing more that the 65 amps I use. Bonus but not sure how long it will stay fine in the peaks lol

 

[RAW]

Carrying on From this testing and as it has been a sunny couple of days there follows some more insights I have drawn.
I obtained on Facebook Marketplace one of these quite cheaply- £9:

So it is PWM and like this

It seems to be pretty good.
When I was running the Victron with the 50W panel the battery was not charging or at least the voltage was not increasing, I suspect that this was because the power generated by the solar panel where it is was only sufficient to power the MPPT controller and not sufficient to charge the battery.

Now with this PWM controller it seems to be that the battery voltage is increasing, therefore the battery is getting some charge now
On Wednesday the Voltage was 12.73V

Thursday increase to 12.75

Friday maintains at 12.75


As I will be using the Solar Panel on the Dash in the Van to keep the engine battery topped up because there is a drain from something and I am struggling to find it I think using this controller will probably do the Job

 

[RAW]

More testing down the timeline
There is more light now as we move closer to the Equinox

The LTD1220D PWM has been attached for some time now and these are the readings from the Battery Monitor, although some voltage was lost whilst I was testing the cheap USB 4 Port Supply that I have posted about here motorhomebuilder.com/threads/nice-little-4-port-usb-buck-boost.66920

I still have the 4 Port USB connected up so that's drawing some Power as is the small Victron Battery Monitor, but here are the evenings stats after the Sun goes down or Solar Panel no longer producing energy.

29th March	30th March	31st March

This would suggest to me that there is not much more than the draw from the devices being produced by the Solar Panel which would be
Small Battery Monitor as described here draws : 0.005A when off
The Solar Charger When getting no Solar draws : 0.05A
The Victron battery Monitor draws : 0.016A
The 4 Port USB described here : 0.265A
A bit of Math
0.265+0.016+0.05+0.005 = 0.336 A

P = IV 0.336 x 12.6 = 4.236 W

Just a trickle really though as stated the panel is behind a window that's not very clean and also North Facing with trees in front and recently it has been predominantly cloudy.
As the Flexible Solar panel is small'ish measuring only 43cm x 22cm or thereabouts I have bought another one which I believe is probably the same make direct from China (ebay link below) and I have a cunning plan for the two as they will be easy to store as small.
Will explain the cunning plan in a new thread when I have both panels in hand.

50W 12V Solar Panel USB Battery Charger Car RV Boat Home+10/20/30/40A Controller | eBay

Find many great new & used options and get the best deals for 50W 12V Solar Panel USB Battery Charger Car RV Boat Home+10/20/30/40A Controller at the best online prices at eBay! Free delivery for many products!

www.ebay.co.uk

 

[Nabsim]

More testing down the timeline
There is more light now as we move closer to the Equinox

Minor correction, the equinox's was last month, do you mean Summer Solstice? I m still a bit peeved that I decided to start my lockdown back in Feb so missed it

 

[RAW]

do you mean Summer Solstice?

YES

 

[Nabsim]

YES

Ha ha dont worry, I only know because I spend a lot of time on the drove with the druids lol

Well I did but not since the end of January