Charging starter and leisure batteries via solar panel.

[hoggle]

Hi All, I was experiencing that my starter battery was going flat due to not being used during this lock down. So, with help from @Dellmassive.
He suggested that i bought a 50w solar panel and to connect it to one of the 12v sockets in the dashboard. I also bought 2 x BM2 battery monitors and connected them to both the starter and leisure batteries.
I have a CTEK 250se Dc-Dc charger fitted, bought from @travelvolts. This morning i went out and using the BM2 app on my phone, i took the following screen shot of the starter battery, this was from yesterday when the van wasn't started or ran..
So, you can clearly see that the solar panel is keeping the starter battery charged.
The next screen shot is of the leisure battery, i wasn't expecting the solar panel to charge the leisure battery.

But as you can see, it is. In fact the voltage is reaching 15v when charging. So, @Dellmassive. Do you think that what's happening here is ok? If so, then all good. And i'm aware that this is under perfect conditions whilst the sun is shining as it is at the moment. Though, as i live in Inverness, this isn't always the case!

 

[Dellmassive]

It looks like the ctek 250se is picking up the higher voltage from the starter battery and kicking in, charging the leisure battery.

14.9v is ok for an initial start charge from the charger.... ie bulk.absorb.float...... but then you would expect the voltage to drop after a while.

What battery setting (charge profile) is the 250se set too?

Have you got the 250se connected to an ignition or BCM run feed?

I haven't had a 250se to test . . . . So does anybody know if the 250se will auto start anyway regardless of the ignition input if the starter battery is high enough?

@Deaky @travelvolts @Fish May have a personal experience with the 250se.


In the meantime I'll have to get one and do some testing
.....


If that is the case that it is auto starting then that can be a bonus as its keeping both batteries topped up (weather dependent)

 

[hoggle]

Firstly, it's actually a D250SA, if that makes any difference? And i do have it connected to a switched live in the fuse box. And thanks for your reply! And as you can see from the screen shots, it is charging both the batteries. Whether it is meant to do this or not, that's another thing!

 

[Dellmassive]

all looks good to me.

so it says bellow.

with the smart setting (with ignition feed) charging starts : >11.8V, for 5 sec. (engine running, alternator charging

without :
Conventional alternator cut-in >13.1V, for 5 sec. (engine running, alternator charging)
Conventional alternator cut-out <12.8V, for 10 sec. (engine running, alternator not charging)


so im thinking that even though you have the "smart" setting enabled.. . . .

the d250sa is seeing ">13.1v for 5sec" and kicking in anyway . . .

but we would need someone else who has one to confim.



************************************************************************************

D250SA

40-186

www.ctek.com

https://www.ctek.com/storage/ma/098556a60fe149fbbfcce982c1908dd9/d975dd519ea8488ba0b08a8e3b20a3b7/pdf/3A13F195BD4645989C4A08BE28B6934E7C6A83D5/D250SA-manual-low-UK-EN.pdf

.

 

[Deaky]

It looks like the ctek 250se is picking up the higher voltage from the starter battery and kicking in, charging the leisure battery.

14.9v is ok for an initial start charge from the charger.... ie bulk.absorb.float...... but then you would expect the voltage to drop after a while.

What battery setting (charge profile) is the 250se set too?

Have you got the 250se connected to an ignition or BCM run feed?

I haven't had a 250se to test . . . . So does anybody know if the 250se will auto start anyway regardless of the ignition input if the starter battery is high enough?

@Deaky @travelvolts @Fish May have a personal experience with the 250se.


In the meantime I'll have to get one and do some testing
.....


If that is the case that it is auto starting then that can be a bonus as its keeping both batteries topped up (weather dependent)

The only 250se experience I have is chucking it in the bin after I blew it up with my solar panel

 

[Dellmassive]

The only 250se experience I have is chucking it in the bin after I blew it up with my solar panel

Lol... yeh.

Just for the record you replaced it with a Redarc?

BCDC1240D?

 

[Deaky]

Lol... yeh.

Just for the record you replaced it with a Redarc?

BCDC1240D?

Yes and a separate Victron MPPT

 

[boxelder]

all looks good to me.

so it says bellow.

with the smart setting (with ignition feed) charging starts : >11.8V, for 5 sec. (engine running, alternator charging

without :
Conventional alternator cut-in >13.1V, for 5 sec. (engine running, alternator charging)
Conventional alternator cut-out <12.8V, for 10 sec. (engine running, alternator not charging)


so im thinking that even though you have the "smart" setting enabled.. . . .

the d250sa is seeing ">13.1v for 5sec" and kicking in anyway . . .

but we would need someone else who has one to confim.



************************************************************************************

D250SA

40-186

www.ctek.com

https://www.ctek.com/storage/ma/098556a60fe149fbbfcce982c1908dd9/d975dd519ea8488ba0b08a8e3b20a3b7/pdf/3A13F195BD4645989C4A08BE28B6934E7C6A83D5/D250SA-manual-low-UK-EN.pdf

View attachment 66775


View attachment 66774.

I'm seeing this at the moment. 100W mobile panel connected to the starter battery and charging, then I notice that the lights on the CTEK are on to show solar charging and the BM confirms that charging is happening. I was starting to think the CTEK was knackered, so good to find this. I disconnected the solar input cable from the CTEK and it continued charging with the solar lights lit. It must recognise that it's solar charge from the fluctuations in input??
@hoggle - were your solar charge lights lit on the CTEK, can you remember?
Starter battery:


Leisure battery


Confirmation that I was going mad and had an extra panel plugged in somewhere - solar charge indication


So plug a solar panel into the starter battery (via PWM etc) and it will charge both batteries. Plug panel into CTEK direct and it will charge Leisure then starter. Plug panel into leisure battery (via PWM) and it just charges the leisure battery.
Having seen that, I'm back to having issues getting the CTEK to recognise the panel plugged in directly to the CTEK (new battery on 100% charge)