Can I charge main battery from mobile solar panel?

Lord Mfwic

I'm Batman.
T6 Legend
Hi,
I won't be using my van for a few weeks so I wanted to top up the battery from my mobile solar panels.
I have the magic box the solar came with and also came with crocodile clips. I believe the battery has some little box of tricks attached to it that reads the charge in and out so its not just a case of attaching the crocodile clips to the battery.
Do I connect the live to live and the neg to a ground under the bonnet or does it require more than that?

TIA
 
Live to live and ground to a chassis ground...... not the battery NEG post.

Or adapt a 12v plug and just plug into dash socket.
 
Because of the battery monitoring sensor fitted to the negative terminal.

If you go directly to the negative terminal you bypass the sensor and the battery monitoring system is unaware of the additional charge the battery has been given

This causes issues with start stop.
 
Because of the battery monitoring sensor fitted to the negative terminal.

If you go directly to the negative terminal you bypass the sensor and the battery monitoring system is unaware of the additional charge the battery has been given

This causes issues with start stop.
I have coded out my stop start. So is that the only issue it causes?
 
@True Romance . . . what @S700 said. . .

don't bridge out the NEG post sensor. - You might end up with a flat battery if you play with things.


@Lord Mfwic - there is a few grounds in the same area, see here:







have a look at the "quick connects" option here :







have a look at getting the 12v plug option for your solar here (upto 100w max) :






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So, I hooked up my solar as mentioned above. I found a great earth on the engine block. My new battery monitor arrived so hooked that up as well. All was going swimmingly in-between the snow showers. Kept checking the new BM and it was ranging between 13.6-14v so I was very pleased with my days set up until around 4pm.
My phone connect to the BM on my leisure battery and this showed that was also charging. Result I thought to myself but alas, that was not the case. It seems that because my main battery was getting a charge from the solar, my leisure battery thought whoopee, I going to take some charge as well. Now because the day was sunshine and showers there was little solar energy going into my main battery but my leisure battery did not care about this and decided it wanted a full charge. Consequently, not only did it take all the solar energy going into my main battery but it also took all the power it had.
So I ended up with a fully charged leisure battery and a fully flat main battery and thats a bit shit.
Rethink required.
 
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It sounds like you might have a voltage triggered B2b charger? You may need to configure it to operate with the engine running (first prize) or ignition on.
 
It sounds like you might have a voltage triggered B2b charger? You may need to configure it to operate with the engine running (first prize) or ignition on.
Whilst I thank you for your advice. Sadly, I have no idea how to do that. :(
 
First step is to identify which battery to battery charger it is. The most likely location for it is alongside the leisure battery. You might also have some paperwork identifying the unit from whoever installed your electrics?
 
Eventually all batteries will be charged.
Mine are mobile solar panels so I can’t just leave it on the van 24/7. I’ll try again at the weekend when I have more time to charge both.
I was a just little perturbed that the leisure battery took all the juice for the starter.
 
First step is to identify which battery to battery charger it is. The most likely location for it is alongside the leisure battery. You might also have some paperwork identifying the unit from whoever installed your electrics?
I’ll have a look at the set up over the weekend but electrics is like the dark arts to me.
 
from memory, @Lord Mfwic has an Ablemail 12-12-30A? or the 12-12-15A DC-DC charger.? - a travelvolts supplied item. (it was july 2020 when i see it last)

not sure if it had the Solar input feature?

this unit has in IGN REMOTE input - as well as the "AUTO VSR" function, that they call "engine run detection"







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15A version . . .


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@Lord Mfwic - its the black box thingy under the drivers seat at the front . . . . maybe take a couple of pics of the black box and cable connections. and post them here?

.
 
I have an Ablemail 12-12-30 (the model without solar input) and mobile solar with Victron MPPT controller. When connected to the starter batt via the cig lighter the solar does trigger the Ablemail. I have found that after disconnecting the solar the Ablemail continues to charge the leisure for approx 10hrs and then it shuts down. I don’t know what triggers the shutdown but it happens regardless of the state of charge of the leisure batt. It has never taken the starter batt down much below 12.4v though.

Photo of connections below.

213B4209-F7BF-42F9-9D56-D9E6FCD1752C.jpeg
 
I've sent an email to Ablemail tech support . . .

this is the reply:


"So Ams voltage senses and switches off at 12.40 and so second user operation is as I would expect (@Higgidav )

The first user has an issue for that operation. I have heard of a Bmv causing a continuous discharge by feeding back from the output but the solar should switch off at 12.4V ( @Lord Mfwic )"


So the Lords starter battery - the dc-dc charger shout shut off at 12.4v . . .

what as the BM2 readouts? . . . . can you screenshot them here?
 
from memory, @Lord Mfwic has an Ablemail 12-12-30A? or the 12-12-15A DC-DC charger.? - a travelvolts supplied item. (it was july 2020 when i see it last)


@Lord Mfwic - its the black box thingy under the drivers seat at the front . . . . maybe take a couple of pics of the black box and cable connections. and post them here?

.

If so the device appears to be programmable by a propriety serial interface. I don't see the software on their site, possibly it's bundled with the £200 serial cable.

If your need for solar charge is infrequent you might just pull either the input or output fuse. This will stop the leisure battery gobbling all the solar energy. Replace fuse once solar is disconnected.

If you will charge more frequently I'm sure @travelvolts has a good solution.
 
I’m not sure how helpful this will be but I have a similar set up but with a Sterling charger.
As soon as the voltage to the vehicle battery reaches a preset level the Sterling kicks in and begins to charge the leisure battery.
however once the leisure battery is charged (or the charge voltage into the vehicle battery drops below a preset level) the Sterling shuts down and all the available charge then goes just to the vehicle battery.
it works really well for me as it keeps both batteries charged and I have never had it discharge the vehicle battery.
 
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