Help! Is my EHU actually charging my batteries?

[trevskoda]

You could fit a voltage down stepper to reduce on the lighting circuit, I had to go the other way with my tv, below 12.4/5 sound vanished, so a up voltage buck rased it to 14.3 steady from 14.4 down to 11v if i went that low on the battery, I wont of course as 12.2 is my max.

 

[merl]

I remember that one Trev.
All I did was ditched the cheapo LEDs and spent a bit more (Real cheapskate me!) The second ones were really great and super efficient and had their own little driver/buck converter incorporated into each unit and their current decreased nicely when on EHU.
I've always been puzzled why the all the manufacturers of 3 way fridges show stats at 12V when in reality the supply voltage is really 14.4V as they are always powered by the alternator. Even after taking the voltage drop of the cable into consideration they all seem to sit at voltages higher than 12V and all that I've measured actually draw more current than their spec suggests and often draw currents GREATER than their recommended fuse rating.

 

[RSD7a]

Ok my next step is to create a convenient mains power source for the new charger.
There's a mains plug v close to the wardrobe and the leisure battery lives in a decent space underneath the wardrobe false floor. I'm thinking of extending the mains power from the existing plug through into the wardrobe.
But I'm not sure how, or it's possible/wise to create a spur from the back of the plug. If I could do that, it would be easy to run cable down to near the leisure battery and install another mains plug from where the new charger would run.

I'd welcome any advice on how to convert the existing mains plug socket into one that will take the mains power another meter or so into the wardrobe. I presume that's doable.

 

[merl]

You simply run a cable from the socket you've exposed and your new socket and connect up at both ends. You MUST use flexible multistrand cable (referred to as flex) DONT use the flat grey stuff which is solid core.
Use 1.5mm.

 

[wildebus]

Only10A from a 25A charger Overstating current capacity seems to be standard practice with all the standalone chargers (Chinese) on ebay/amazon etc, they know that peeps with a DC clamp meter will be few and far between but I wouldn't have expected it from Sargent, very naughty.
In an earlier MH of ours I fitted some cheapo led replacements to the lights, the sort with multiple SMD leds, everything was fine when off grid but when we were on a site with EHU, the charger was on it's bulk phase and so eventually the system was up to around 14.7V and at this point the LEDs got so hot they unsoldered themselves from the board and fell off!
Maybe it's the fear of overvoltage that makes Sargent feel they have to use what's basically a power supply rather than a full blown charger? Who knows as it's not a choice other manf make and other than my LED experience I've never come across 14.4V+ affecting equipment, have you?

I would say it is a cost excercise. I have a few PSUs of identical style to the ones in the Sargent systems. They are very cheap, especially compared to multi-stage chargers.
There is one Sargent PDU (can't recall which) that is a bit weird. It contains some kind of multi-level charger, but not multi-stage and it puts something like 15.4V into the battery which gets disconnected, but a lower voltage to the 12V circuits. I don't like that at all as if you connect something directly to the Battery (say a extra 12V socket), you will be putting that high voltage on a device that is really happiest at around 12-14V.

Ok to have 14.4V+ on equipment? Wouldn't like to say for "Motorhome" kit but I would not like to run a lot of the stuff I personally have fitted at that voltage as it is domestic kit that is designed for a regulated 12V. You mentioned LEDs failing? A common failure you read on the VW Forums is with LED failures and basically down to buying IKEA LEDs and bypassing the 240V AC - 12V DC regulator.
I use a Victron Orion Smart Tr 18A DC-DC converter as a regulated 12V Power Supply which then feeds into my Sargent to make sure the Hab Electrics are fed with a 12V supply (I actually have it set at 12.3V as there are losses within the PDU). IF I turn on the Sargent Charger, the voltage shoots up to 13.8V but I only use that very occasionally to charge the Starter Battery if for any reason it has not been maintained sufficiently by the AMT (poor solar and no EHU for a time).

 

[wildebus]

Ok my next step is to create a convenient mains power source for the new charger.
There's a mains plug v close to the wardrobe and the leisure battery lives in a decent space underneath the wardrobe false floor. I'm thinking of extending the mains power from the existing plug through into the wardrobe.
But I'm not sure how, or it's possible/wise to create a spur from the back of the plug. If I could do that, it would be easy to run cable down to near the leisure battery and install another mains plug from where the new charger would run.

I'd welcome any advice on how to convert the existing mains plug socket into one that will take the mains power another meter or so into the wardrobe. I presume that's doable.

View attachment 118207View attachment 118206

What Brand of Motorhome do you have? You might find there is a Mate 'n' Lock Connector somewhere lower on that white flex. You could make (or have made) a spur to come off that connector which would be the neatest way to do it.
This photo shows the connectors you would look for .....

There is nothing wrong with adding a second cable to the socket itself but be aware that those CBE sockets can be fiddly to work with.

 

[RSD7a]

What Brand of Motorhome do you have? You might find there is a Mate 'n' Lock Connector somewhere lower on that white flex. You could make (or have made) a spur to come off that connector which would be the neatest way to do it.
This photo shows the connectors you would look for .....
View attachment 118208


There is nothing wrong with adding a second cable to the socket itself but be aware that those CBE sockets can be fiddly to work with.

Interesting. There's not much slack on the white cable and then it's inaccessible for quite a distance, so I don't think I'll find a mate n' lock. The cabling on the plug does though does look quite tight, so squeezing in an additional cable might be hard. Instead could I break into the white cable and use some kind of mate n' lock device to supply the existing plug with a spur to my new extension? Maybe that's partly what you were suggesting? If so, I can't quite figure out the necessary bits from your photo.
Thanks again!
(My PVC is by Devon Conversions in Co Durham btw)

 

[wildebus]

Interesting. There's not much slack on the white cable and then it's inaccessible for quite a distance, so I don't think I'll find a mate n' lock. The cabling on the plug does though does look quite tight, so squeezing in an additional cable might be hard. Instead could I break into the white cable and use some kind of mate n' lock device to supply the existing plug with a spur to my new extension? Maybe that's partly what you were suggesting? If so, I can't quite figure out the necessary bits from your photo.
Thanks again!
(My PVC is by Devon Conversions in Co Durham btw)

I was wondering the make as I don't know if everyone who fits Sargents use the Mate 'n' Lock system as well? Autotrail do and it makes it quite simple to remove a 240V socket to work on.
The white flex is actually relevant. The recommended colours for AC Flex with Sargent are White, Black, Blue, Yellow and Orange depending on the purpose of the circuit. White is used for Sockets.

My photo was really to show you what the connectors looked like. It was not on an actual Sargent system (just a Consumer Unit I built using the same type of connectivity).

 

[trevskoda]

I just have my charger mounted in the electric box/unit with the rest of the cr-p, its output joins the wires out of the solar which in turn are conected to the battery bank, make sure you have a polarity changer switch if going over the big pond as many are reversed.

 

[RSD7a]

You simply run a cable from the socket you've exposed and your new socket and connect up at both ends. You MUST use flexible multistrand cable (referred to as flex) DONT use the flat grey stuff which is solid core.
Use 1.5mm.

I read on some self build site to use 2.5mm. Would that be overdoing it? I'd prefer to use the thinner 1.5 mm when doubling up the wiring behind the existing socket. That would ease the fiddly task wouldn't it ?

 

[wildebus]

I read on some self build site to use 2.5mm. Would that be overdoing it? I'd prefer to use the thinner 1.5 mm when doubling up the wiring behind the existing socket. That would ease the fiddly task wouldn't it ?

If it is a spur off to use for the charger, then 1.5mm or 1mm would be fine. You won't be pulling anywhere close to the current that would need 2.5mm.

 

[Pudsey Bear]

2.5 flex is good for at least 3kw, B&Q do a flex that is good for 6kw, god know what or where you would use it though.

 

[merl]

I read on some self build site to use 2.5mm. Would that be overdoing it? I'd prefer to use the thinner 1.5 mm when doubling up the wiring behind the existing socket. That would ease the fiddly task wouldn't it ?

Slightly I guess and would be ok as long as 1mm is protected by the original 10A breaker. If the breaker has been swapped for a 15A breaker then stick with 1.5mm. OR remove the new socket if you sell the van.
Slacken off the cable clamp and pull as much spare through as you can. then bring your new cable trough from the back preferably also via the cable clamp (1mm will help probably) If not drill a hole in the back ideally thats a tightish push fit for the new cable, insert the new cable and connect up to the existing, and do a stiff tug test before pulling the cables back so the insulation is just inside the cable clamp/hole.
Re fit.

 

[RSD7a]

I've already ordered some 1.5mm in the end.

Now to the breakers you mention. I'm really in unchartered territory (for me) here. So schoolboy questions follow. I don't understand where the breaker (that's a fuse, right?) would go. Am I meant to break into the spur to fit a 15amp breaker? What would it look like?

I now have the same 12V 30A Leisure LCD Battery Charger For Caravan Campervan etc to install that you recently purchased. Would that have a breaker built in?
You can see I'm a minus square one.

 

[wildebus]

I've already ordered some 1.5mm in the end.

Now to the breakers you mention. I'm really in unchartered territory (for me) here. So schoolboy questions follow. I don't understand where the breaker (that's a fuse, right?) would go. Am I meant to break into the spur to fit a 15amp breaker? What would it look like?

I now have the same 12V 30A Leisure LCD Battery Charger For Caravan Campervan etc to install that you recently purchased. Would that have a breaker built in?
You can see I'm a minus square one.

The Breakers are the MCBs (Miniture Circuit Breakers) fitted in the EC155.
You don't need to make any changes to the breakers - the Sockets are protected by a 10A MCB which is fine.

 

[Chrisinchip]

I would still not recommend using the Sargent Charger with Lead Carbon. It won't hurt it, but neither will it properly fully charge it.

The important thing is that the big killer of lead acid batteries is leaving them in a partially discharged state which the Sargent is obviously guilty of. Now this wont be an issue with Lead Carbon and the OP wouldn't now be faffing with alternative chargers in order to keep the battery from sulphation.
Agree, it's not perfect because you wont get 100% of battery capacity but the OP or anyone else using this Sargent charger doesn't get 100% battery capacity anyway and that's obviously never been an issue so WRT capacity so they wont know a difference anyway.
Fit a lead carbon is the simplest means to an end and will be an excellent recommendation to many.

Great point; I am a Sargent EC155 user with capacity concerns. At the moment I'm blaming the lack of a DC-DC charger despite the vehicle being Euro 6 with a smart alternator, but this discussion brings the EC155 well into the picture.

 

[Chrisinchip]

I'm mapping this really useful thread to my situation. A key message in later posts is that Sargent are good for power distribution but not for charging so add separate charging units. I have a 5m campervan so space for mounting equipment, especially in ventilated space is really tight. I can see how converters are attracted to the EC155 as it purportedly meets the relatively small needs of a campervan but as this thread shows it does not do this well. Moreover, it is not Lithium ready, an obvious battery upgrade for compact vans wanting to improve off-grid capability.

I really don't have the ventilated space for a separate DC-DC charger, larger solar controller, and EHU charger so now I feel conflicted:

1. Research a single box to replace the EC155 or compromise on one or more of the charging sources (EHU would be the obvious compromise)?
2. Then what if in the future Lithium looked like the way forward, get a new van?
3. Use the boss's clothes storage?

Grateful for any help with this decision.
Apologies for highjacking the OP's question but this seems a natural progression so hoping it does not violate etiquette.

 

[Okta]

Great point; I am a Sargent EC155 user with capacity concerns. At the moment I'm blaming the lack of a DC-DC charger despite the vehicle being Euro 6 with a smart alternator, but this discussion brings the EC155 well into the picture.

If you have a smart alternator and no B2B it is quite possible that your leisure battery will be discharging into you engine battery whenever the engine is running and the smart alternator voltage drops. A split charge relay is a crude device that opens the way for current to flow in either direction, either to or from the leisure battery. They are installed on the assumption that all the time the engine is running the alternator will be producing power at a voltage of about 14V. However with a smart alternator this doesn’t happen, it will spend a lot of time switched down to a much lower voltage allowing a fully charged leisure battery to discharge into the engine battery. The smart alternator will say “thank you very much I don’t need to do any charging the leisure battery is doing it all for me” (this is a very smart alternator that can talk ).

My opinion is you need to sort out the lack of a B2B first. No point in having the worlds best mains charger if a split charge relay is sometimes pouring the power out to the engine battery. First I would talk to the motorhome manufacturer about why there is no B2B (sometimes called a power booster or DC to DC charger). This is not a new issue and they should not be selling a van with a well known problem.

 

[Pudsey Bear]

If you have a smart alternator and no B2B it is quite possible that your leisure battery will be discharging into you engine battery whenever the engine is running and the smart alternator voltage drops. A split charge relay is a crude device that opens the way for current to flow in either direction, either to or from the leisure battery. They are installed on the assumption that all the time the engine is running the alternator will be producing power at a voltage of about 14V. However with a smart alternator this doesn’t happen, it will spend a lot of time switched down to a much lower voltage allowing a fully charged leisure battery to discharge into the engine battery. The smart alternator will say “thank you very much I don’t need to do any charging the leisure battery is doing it all for me” (this is a very smart alternator that can talk ).

My opinion is you need to sort out the lack of a B2B first. No point in having the worlds best mains charger if a split charge relay is sometimes pouring the power out to the engine battery. First I would talk to the motorhome manufacturer about why there is no B2B (sometimes called a power booster or DC to DC charger). This is not a new issue and they should not be selling a van with a well known problem.

That's a new one on me, never heard of that happening, not saying it doesn't just never reading it on any forum.

Everyday a skool day.

 

[Chrisinchip]

If you have a smart alternator and no B2B it is quite possible that your leisure battery will be discharging into you engine battery whenever the engine is running and the smart alternator voltage drops. A split charge relay is a crude device that opens the way for current to flow in either direction, either to or from the leisure battery. They are installed on the assumption that all the time the engine is running the alternator will be producing power at a voltage of about 14V. However with a smart alternator this doesn’t happen, it will spend a lot of time switched down to a much lower voltage allowing a fully charged leisure battery to discharge into the engine battery. The smart alternator will say “thank you very much I don’t need to do any charging the leisure battery is doing it all for me” (this is a very smart alternator that can talk ).

Absolutely agree. When I installed an LB in my previous vehicle (a Mazda Bongo) I used a VSR triggered by a positive differential between SB and LB. I reckon the EC155 uses an "Engine Running" signal to trigger the relay so the scenario you describe is absolutely feasible; I had suspected as much when we arrived at site after 2 hours drive and the LB had a lower voltage (based on EC50 LEDs) than when we left home. I thought I was dreaming it.

My opinion is you need to sort out the lack of a B2B first. No point in having the worlds best mains charger if a split charge relay is sometimes pouring the power out to the engine battery. First I would talk to the motorhome manufacturer about why there is no B2B (sometimes called a power booster or DC to DC charger). This is not a new issue and they should not be selling a van with a well known problem.

Thanks for the pointer. Really appreciate having my thoughts confirmed. That is where I am heading.
Priority 1 = B2B.
Priority 2 = bigger solar (I have a compressor fridge so 100W solar not enough to stretch the battery to 4 days, which is my aim).

My concern is that if eventually the EC155 has to be ditched, would adding in B2B and solar controller piecemeal be wasteful in the long run?

[edit] I've been in touch with the van manufacturer. In fact it came to light when I asked them to quote for a Litheum upgrade and the quote included a ridiculous charge for supplying and fitting a B2B. I've since found out that they fit B2B now as standard. You've nudged me into chasing them again now that I'm better educated.
Thank you.