[Guide] Mobile Solar Panels ? . . . - How I Did It -

OK, with the sun out, I've got this sorted. With the extra 'pigtail' I bought to connect panel to CTEK, I was measuring 22V and 4+Amps at the ring terminals and on the centre of the studs that clamp the cable connectors to the CTEK, but it wasn't charging. I cut the ends off a spare lead that came with the panel and connected some 8mm ring terminals. On the other end is the male/female connectors used by the supplied PWM. Attached the panel straight to the CTEK via those and bingo - charging lights and charging shown on the BM monitor.

All I can think is that the ring terminals on the extra lead I bought were too big and didn't make a decent connection - doesn't explain the 22V/4A metered at the allen bolt heads on the CTEK though........??
Ah well, working now. Thanks again for your help folks - crap connection after all (or was it o_O)
51089954094_91db776a85_w.jpg51089985482_45a440140e_w.jpg51089968504_585ee729d1_w.jpgThis is the extra pigtail lead I bought to connect panel straight to CTEK
 
Arghhh, just when I thought it was sorted........ Had the panel charging yesterday and went out in the van today to go hill walking. couple of hours driving in total, but the BM was saying 0% charge on the leisure battery at 9pm. Had a look and though the panel hasn't been connected for 24 hours, the CTEK has the lights on to indicate it is charging from solar, and the BM monitor was showing a fairly rapid loss of charge through last night, and since I got home at 1pm. I've put a mains charger straight on the leisure battery and will leave overnight. Nothing was drawing power (or nothing more than usual). Could it be that the CTEK has been passing charge from the leisure battery to the starter for some reason?? Strange. o_O
 
Arghhh, just when I thought it was sorted........ Had the panel charging yesterday and went out in the van today to go hill walking. couple of hours driving in total, but the BM was saying 0% charge on the leisure battery at 9pm. Had a look and though the panel hasn't been connected for 24 hours, the CTEK has the lights on to indicate it is charging from solar, and the BM monitor was showing a fairly rapid loss of charge through last night, and since I got home at 1pm. I've put a mains charger straight on the leisure battery and will leave overnight. Nothing was drawing power (or nothing more than usual). Could it be that the CTEK has been passing charge from the leisure battery to the starter for some reason?? Strange. o_O
Post some BM2 readouts and well have a look...
 
Here's the day - drive 6.50-7.45, parked up while walking, drive back midday til 1pm, with stop for fuel. Plugged into 7A CTEK mains charger at around 8.15pm after briefly having ignition on. Charger decided it was about charged in under two hours and dropped the charge voltage. I'll leave it on overnight, but looks like a BM monitor issue if a 7A charger can get it back to health in under two hours - 12AH? I've never seen that rapid discharge before. The only thing that changed prior to this, was my adding the 'permanent' quick connect to the starter battery. I'll plug the solar in again tomorrow (if there's sun) and then unplug and see if the CTEK behaves.
EDIT: I did also charge the starter battery on Wed when my mains charger arrived and it was croc clipped straight to +ve and -ve battery terminals. I've done that once before though, with a borrowed 10A charger.

Screenshot_20210407_223916_com.dc.battery.monitor2.jpg
 
theres something not right there . . .

The battery shouldnt be dropping to 11.5v at rest, thats way too low.

it should stay above 12.0v at rest.

do you have trouble restarting it the following morning?? - or is this chart from the AUX battery?

i would say that looks like a very low battery that needs a good 24hr charge - but if you say the charger is showing its 100% after a couple hours, then that makes me think the battery has a very low state of health?

unless you have something constantly drawing power from the battery, causing the voltage to drop so low?

id like to see a few more 24hr plots to compare the rate of drop on the battery.

maybe try disconectiong any loads from the battery for 24hrs and see if the plot changes.

my gut feeling at thisd point is the battery is knackered and cant hold a decent charge - how old is it?, has it been run flat a few times?
 
if you do this in future:

EDIT: I did also charge the starter battery on Wed when my mains charger arrived and it was croc clipped straight to +ve and -ve battery terminals. I've done that once before though, with a borrowed 10A charger.

you should use a body or chassis ground - not the battery NEG post.






1617858167942.png

.
 
As an example.... this is my AUX battery readout.. (the only loads are USB chargers, nit charging anything over night)

.

Screenshot_20210408-071605_Battery Monitor.jpgScreenshot_20210408-071553_Battery Monitor.jpg

...


And starter.....

Screenshot_20210408-063731_Battery Monitor.jpg



.
 
It's the leisure battery. No loads other than BM monitor and a small led on a usb point. Not been run flat and my read outs normally look like yours. The cause is presumably that the CTEK had the green/orange indicators on to show it charging via solar. It's been on mains trickle all night at 13V and the mains charger showing charged. There's no way it was as low as the BM showed, for a 7A charger to recharge it so quickly. I'll keep an eye on it today to see if it discharges. I disconnected the solar quick connect from the CTEK and those indicator lights have cleared.
On the charger, I've since used your light mounting bolt earth solution - all good. Cheers.
 
After reviewing the BM monitor graphs, the leisure battery has run below 10V for a few days, a couple of weeks ago. I wasn't using the van, so no charging going on. No real draw on the battery though - fridge, lights etc all off. I'm suspecting the battery is knackered.
 
just checking a point. You said the CTEK was showing solar was charging even though the panel was disconnected. Are you certain it wasn’t the CTEK showing an error condition, the lights displayed are very similar. Could there be a dodgy connection between the CTEK and the leisure battery or ground?

6B0B46FE-440D-42FF-86D9-F1F337FCA9A2.png
 
just checking a point. You said the CTEK was showing solar was charging even though the panel was disconnected. Are you certain it wasn’t the CTEK showing an error condition, the lights displayed are very similar. Could there be a dodgy connection between the CTEK and the leisure battery or ground?

View attachment 111853

Thanks @Big.mac - I did check that, but there was no light top left (!). I think the battery is FUBAR'd. Whether having it run to really low for a few days and then hitting it with solar charge and mains charging has caused this, I don't know. Plan is to remove the battery and charge it fully using 7A mains charger, then see if it can hold charge. The battery has a 3 year warranty, but the small print on that may stipulate that you sing nursery rhymes and give it motivational speeches every couple of weeks :notworthy:
Here's today's BM monitor trace, after mains charge overnight, discharge/drain, another mains charge, a few short trips and the fridge going on :eek:
Screenshot_20210408_220126_com.dc.battery.monitor2.jpg
 
i think that batterys is done . . . .

for it to be at float charge @ 13.2v for a number of hours,

then drop at rest to under 12.0v,

then drop to under 10.v with a load . . . . . . . its toast.

i think you need a new battery... ( most likley caused by it being left at a low voltage for a while and not being fully charged all the time )

got a pic of the battery? . . . is just s standard SLA?. . . . AGM ?

1617944080419.png

....


you coulod try taking it out and charging it . . . . . but from experience it will just sit there, the charge will test you its 100%, then you connect a load and it will drop in voltage instantly.

maybe take it a battery place for free testing . . .? ( ie Halfords)

or get yourself a your own battery tester and test it yourself:





1617944304300.png



+++


i have this one . . . .






1617944366395.png1617944381844.png
 
Hi all,

I wanted to hopefully add some value to this thread... not sure i will but here goes.

My T5.1 is fitted with a leaisure battery under the seat, there is a small invertor and somewhere under teh dash VanWorx fitted a split charge relay.

After speaking with @Dellmassive i decided to upgrade things a little. First of all 2 BM2's so i could check the state of the Aux battery and the starter battery. - Love these little things my naighbour who is car mad, has since bought 3 for his kit cars!

The first thing i needed to do was find a simple way of charging the battery when docked - i think its termed Land side charging.

I bought a victron bluetooth charger as featured in Dell's posts... brilliant bit of kit. I bought an extension lead and loads fo the little battery clips so on my main car I have a simple plug and play battery charge point. I fitted one to the starter battery, but then started thinking how i was going to charge the leisure battery under the seat, as the relay on the T5 only allows charge through when the engine is running.
I extended the cable from the under the passenger seat from the battery, up through the bulk head and into the engine bay. I now have another Victron quick connect cable (fused at 50amps), one for the starter battery and one for the leisure battery. Simple land side charging now.

I also fitted a smart battery protector switch to stop my cheap leisure battery from going too flat and being beyhond recovery. All the loads now come from that smart switch. (its not bluetooth, but does have an audiable alarm now fitted).

If your still reading this well done. I will get some pictures of the above setup asap.

I then thought hang about, what about solar. So more research on this amazing forum and I bought a 100W Lensun flexible solar pannel (3 pannels), a Victron MPPT Charge Controller 100/50 and some cables and connectors. It arrived today. But once again I'm faced with how do I get that charge down to the leisure battery under the seat. There is no way i have room to fit teh MPPT under the seat with all the other stuff.

The answer was obvious really - make use of the Victron quick connect plug already in the engine bay. So i cut the exstention lead i have for the charger in half, wired the male end into the MPPT controller (battery side). I then fitted some short fly lead MC4 type to the Pannel input side. I have kncoked up a long extension lead to go between the pannel and the MPPT if needed, or i can just plug the pannel straight into the MC4's on the MPPT.

Not very obvious but this is me making the fly leads and extension leads (yes the wife was out hence using the kitchen top :whistle::whistle:)

1618336067368.png
bought some new tools - the MC4 crimp tools - worth having but if anyone in oxford area wants to borrow them give me a shout.. its not the kind of thing i use every day.

1618336091668.png

At about 5pm this evening i plugged it all together. I'm highly delighted with it all:

1618335785697.png

As above.. 3 pannels in sunlight

1618335819017.png
37W shown - the highest i got was 48W and that put about 3.6Amps current output.

My BM2 shows the charge spike in bulk mode at about 16:30 ish then tapers off to absorption at about 16:50
1618335908999.png


I'll update this thread with some pictures of the actual setup. At the moment the MPPT controller gets unplugged from the battery and stored with the pannel. IN theory this means i could use it with any other battery - subject to the proper connection options. I guess this means it wont keep a track of life cycle charge achieved etc but thats a small price to pay.
So thats me ordering a couple more Victro extension cables and the battery quick connects to make that easier on other batteries. I may buy a powerbank so when we go out for the day the fridge can live in the awning and use a bank for power.

A huge thank you :thumbsup: to @Dellmassive wouldn't have been half as easy without your help along the way. Thank you
 
Last edited:
need some help guys, if I had a 120w solar panel with and open circuit voltage of 23.9v, could I still use the c-tek for It? im sure I read somewhere that it would drop below 23v by the time it reached c-tek,
 
need some help guys, if I had a 120w solar panel with and open circuit voltage of 23.9v, could I still use the c-tek for It? im sure I read somewhere that it would drop below 23v by the time it reached c-tek,
thats pushing it.. . .

the spec states 23v voc max.

23.9v might pop the solar input . . . . . havent got one so can test it out?

1618425388846.png

.
 
need some help guys, if I had a 120w solar panel with and open circuit voltage of 23.9v, could I still use the c-tek for It? im sure I read somewhere that it would drop below 23v by the time it reached c-tek,
I personally wouldn’t risk it (and I’m selling a CTEK).
 
really struggling to find a solar solution for the c-tek
just use whatever solar panel you want . . . and get a seperate solar MPPT controller.


or.


stick using the CTEK solar input, but get 2x smaller panels (below 23v voc and run them in parrallel. .)


eg 2x 100w in parallel @ 18v voc
 
Back
Top