Batteries not charging unless not EHU

[Brian123]

Hi everyone hopefully someone can steer in the direction,

I have a 2015 Hymer B690, i have just returned from 5 days being of grid, on day 3 i had to hook up to a generator as my batteries were getting very low. Once i got home i recharge via the EHU and tried to investigate. I have circa 19v going into the solar regulator and circa 12.4v - 12.6v coming out and going into the EBL.
Is there anyway i can check if the EBL is charging the batteries? or could the batteries fooked?

My setup is.....
EBL29
LAS 1218 Bus battery charger
LR 1218 Solar charger
3x 95ahr AGM's

thanks

 

[Richard n Ann]

Looks like Solar regulator has no output. The 12.4 is just battery terminal voltage

 

[funflair]

Did you disconnect the output from the solar regulator to check the voltage?

 

[Brian123]

I discounted from regulator to check the voltage from the solar panels, i then reconnected them and pulled the plug from the EBL to check the volts from solar regulator to the EBL

 

[funflair]

I am not sure that the regulator will work when disconnected from the batteries as it needs to see the voltage to charge, you need to reconnect the regulator to the batteries now and then connect the solar, I check our solar regulator output with a clamp ammeter then it stays connected to the battery.

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[autorouter]

The first thing you need is a method to measure the voltage of the battery, measured at the battery terminals. You can't rely on the panel voltmeter reading, because you are investigating possible faults, and any fault might affect the panel reading.

If the battery voltage is between 12.0 and 12.8V, probably nothing is charging the battery. Try plugging in the EHU. The battery voltage should rise to between 13.0 and 14.8V. If it doesn't rise, it's not charging, so you could investigate why. For example there is a big 50A fuse near the leisure battery. And also a small 2A fuse next to it, on the wire that the EBL uses to measure the leisure battery voltage.

The built-in charger output goes through the 'Internes Lademodul' fuse, and the extra charger (LAS1218) goes through the 'Zusatz Ladegerat' fuse, so you might need to check those.

Next disconnect the EHU, and try the same thing with the solar. If the voltage doesn't rise to 13.0 to 14.8V, it's not charging the battery.

First the obvious. Check the fuse labelled 'Solar'. All the solar power goes though that fuse on its way to the battery.

 

[Brian123]

The first thing you need is a method to measure the voltage of the battery, measured at the battery terminals. You can't rely on the panel voltmeter reading, because you are investigating possible faults, and any fault might affect the panel reading.

If the battery voltage is between 12.0 and 12.8V, probably nothing is charging the battery. Try plugging in the EHU. The battery voltage should rise to between 13.0 and 14.8V. If it doesn't rise, it's not charging, so you could investigate why. For example there is a big 50A fuse near the leisure battery. And also a small 2A fuse next to it, on the wire that the EBL uses to measure the leisure battery voltage.

The built-in charger output goes through the 'Internes Lademodul' fuse, and the extra charger (LAS1218) goes through the 'Zusatz Ladegerat' fuse, so you might need to check those.

Next disconnect the EHU, and try the same thing with the solar. If the voltage doesn't rise to 13.0 to 14.8V, it's not charging the battery.

First the obvious. Check the fuse labelled 'Solar'. All the solar power goes though that fuse on its way to the battery.

Hi Autorouter,

Thank you for your response....

I carried out the checks above,

No EHU connected battery reading 12.89v
With EHU connected battery reading 14.05v (50 & 2amp fuses ok at the leisure batteries) and the additional charger is showing an amber light (which i think means charging)
Checked the solar and charger fuses on the EBL - no issues
Disconnected the feeds from the solar panels momentarily shows 19.25v then immediately the voltage meter displays 1 .v the same happens when I connect reconnect the solar panel wires.

I am starting to think the solar regulator has had it is where anyway other way i can prove it one way or the other

 

[tonka]

Check fuses on the EBL I know when I changed my lr1218 to the MPPT type I blew one when plugging in the regulator lead back into the EBL.

If you do discover the LR1218 is fault , I have my old one lying around somewhere, happy to haggle for some rally beer funds

 

[Brian123]

Check fuses on the EBL I know when I changed my lr1218 to the MPPT type I blew one when plugging in the regulator lead back into the EBL.

If you do discover the LR1218 is fault , I have my old one lying around somewhere, happy to haggle for some rally beer funds

Hi Tonka.....all fuses are ok, can we talk about number of beer tokens

 

[autorouter]

Disconnected the feeds from the solar panels momentarily shows 19.25v then immediately the voltage meter displays 1 .v

The EHU charger side of things looks like it's working, and the battery holding 12.89V is a good sign, it's probably OK.

The solar panel should give out 18 to 24V when the sun shines on them. The voltage shouldn't fall like that when you probe it with a meter. It looks to me like a problem with the solar panels, or possibly the connecting wires.

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[cmcardle75]

Disconnected the feeds from the solar panels momentarily shows 19.25v then immediately the voltage meter displays 1 .v the same happens when I connect reconnect the solar panel wires.

If your multimeter is set to a 20V range, it might display that weird result when the voltage rises above 20V. It probably means that the voltage is higher than the selected range can display. An open circuit "12v" solar panel will be over 20V in any significant light.

 

[Brian123]

If your multimeter is set to a 20V range, it might display that weird result when the voltage rises above 20V. It probably means that the voltage is higher than the selected range can display. An open circuit "12v" solar panel will be over 20V in any significant light.

Hi cmcardle75,

School boy error on my part, when i change the volt meter to the 200v setting i get a reading of 20.8v from the solar panels (cloudy blue skies), so i think the solar panels seems to be ok, the EHU/battery charger is working ok is hook-up, but there is no charge from the solar side to my batteries, so now my very limited thinking it could either be the solar regulator, the EBL (all fuses seem to be good), or duff batteries. I would love to get peoples views with greater knowledge than myself

 

[autorouter]

The solar regulator should be outputting power to the leisure battery if the panel voltage is 5V or more higher than the battery voltage. So if it's 20V or more, the output should be 13.0 to 14.8V. The voltage at the battery terminals should also be about the same as the solar regulator output, allowing for a bit of voltage drop.

If that's not happening, it could be a wiring problem - a bad connection for example. If all the wiring is good, it must be the regulator.

 

[autorouter]

Sorry, just realised the solar regulator LR1218 will be plugged into the EBL solar connector. This connects via the 15A 'Solar' fuse to the inbuilt shunt in the EBL. From that point all the wiring is the same as for the EHU charger - that's OK so the wiring must be OK too. If it's not a bad connection to the solar regulator or the EBL, it looks like a solar regulator problem.

The LR1218 is a PWM regulator. If you're replacing it, think about either an LRM1218 which is MPPT, or a Votronic MPPT Duo which has two outputs, the extra one being for the starter battery. The EBL29 is one of those EBLs that has pin 2 of the solar connector connected to the starter battery, which makes the connection easy. I think Votronic do a wire that is suitable.

 

[Cheshirecat57]

The above 14 posts were mostly Greek to me, with the odd one being Latin

But what a fantastic resource of information this place is for 38p a week ( new rate)

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[busby]

Had same problem in Fra ce this year.Found a fuse I didn't know about on pos wire fom van to leisure battery..Had dull weather for two days so solar charge was negligible..BUSBY.

 

[Brian123]

Sorry, just realised the solar regulator LR1218 will be plugged into the EBL solar connector. This connects via the 15A 'Solar' fuse to the inbuilt shunt in the EBL. From that point all the wiring is the same as for the EHU charger - that's OK so the wiring must be OK too. If it's not a bad connection to the solar regulator or the EBL, it looks like a solar regulator problem.

The LR1218 is a PWM regulator. If you're replacing it, think about either an LRM1218 which is MPPT, or a Votronic MPPT Duo which has two outputs, the extra one being for the starter battery. The EBL29 is one of those EBLs that has pin 2 of the solar connector connected to the starter battery, which makes the connection easy. I think Votronic do a wire that is suitable.

Thanks Autorouter

would my current cable from the EBL to LR1218 not work with the vitronic mmp regulator

 

[autorouter]

would my current cable from the EBL to LR1218 not work with the vitronic mmp regulator

I think the Votronic comes with a number of cables. One to connect the two outputs and negative for your type of EBL, one data cable to inform the display panel of the solar power, and a couple more for other types of EBL that don't have the starter battery on Pin2 of the solar connector. The cable you'd use is similar to the existing one, with an extra wire for the starter battery charging. Actually I'm not sure if all these cables come with it, or ordered separately, but they are available one way or the other.

 

[Brian123]

I think the Votronic comes with a number of cables. One to connect the two outputs and negative for your type of EBL, one data cable to inform the display panel of the solar power, and a couple more for other types of EBL that don't have the starter battery on Pin2 of the solar connector. The cable you'd use is similar to the existing one, with an extra wire for the starter battery charging. Actually I'm not sure if all these cables come with it, or ordered separately, but they are available one way or the other.

Hi Autorouter,

I really appreciate your help and advice. Now to find a Votronic it appears it is rarer than the provable rocking horse muck, everywhere is out of stock

 

[Brian123]

Sorry, just realised the solar regulator LR1218 will be plugged into the EBL solar connector. This connects via the 15A 'Solar' fuse to the inbuilt shunt in the EBL. From that point all the wiring is the same as for the EHU charger - that's OK so the wiring must be OK too. If it's not a bad connection to the solar regulator or the EBL, it looks like a solar regulator problem.

The LR1218 is a PWM regulator. If you're replacing it, think about either an LRM1218 which is MPPT, or a Votronic MPPT Duo which has two outputs, the extra one being for the starter battery. The EBL29 is one of those EBLs that has pin 2 of the solar connector connected to the starter battery, which makes the connection easy. I think Votronic do a wire that is suitable.

Hi Autorouter,
I have managed to get another LR1218 (thx Tonka) however when i plugged this in I still didn't get a charge from the solar, as you say the battery charger via EHU is working so assume the wiring from the back of the EBL to the batteries is sound, could the problem lay within the EBL?

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[autorouter]

Hi Autorouter,
I have managed to get another LR1218 (thx Tonka) however when i plugged this in I still didn't get a charge from the solar, as you say the battery charger via EHU is working so assume the wiring from the back of the EBL to the batteries is sound, could the problem lay within the EBL?

First to state the obvious, you need a good fuse in the 'Zusatz Ladegerat' fuse slot, 20A, to allow the charger plugged into the 2-way connector (Block7) to connect to the shunt and so to the leisure battery. For the inbuilt charger, you need a good fuse in the 'Internes Lademodul' fuse slot, 20A, for the allow the inbuilt charger to connect to the shunt and so to the leisure battery. The two chargers are independent, and the battery should charge from either one or both.

If you have a meter, further checks are possible. One terminal of the fuse slot is supposed to be permanently connected to the leisure battery, so you could check that you are getting the leisure battery voltage on one side of the fuse. This applies to both of the fuses.

If not, check that the leisure battery voltage is present at the heavy-duty terminal block at the back of the EBL. The leisure battery terminal may be labelled 'WB' (Wohnraum Battery). Be aware of the colour code: brown = negative, black = positive.

The non-battery terminal of the Auxiliary Charger fuse slot is permanently connected to pin2 of the 2-way charger connector (Block7). You could check for continuity with the meter.

Similarly the non-battery terminal of the Internal Charger fuse slot is permanently connected to the inbuilt charger output, so you could check for the charger voltage there when the EHU is plugged in and the internal charger is supposed to be working.

 

[Brian123]

Hi all....firstly thank you to everyone for there help and advice, i carried out the checks Autorouter suggested, which all turned out to be ok. However I then decided to check the 50amp fuse at the starter battery, which was blown, once replaced I started getting solar charger immediately. Although frustrating i have learnt a lot about how the charging system works on the van (every cloud....)

P.s. I can only guess that the fuse blew when the Mercedes dealership disconnected the battery on a recent service