No dc power Hymer v2

[mumkin]

Assuming your Twin Cities refers to MSP. You might ask Lake Region RVs up in Ramsey as they used to sell Roadtreks. Hilltop in Fridley sold Carado and Hymer for a short time, but don't know how experienced their service department is with this system. Camping World up north of the cities has one tech named Ted who is familiar with the system. Wouldn't trust anyone else there.

[starrski]

Originally Posted by Driverx1

Hello. I have a 2018 Hymer sunlight v2 with no dc power even when plugged in to shore power. No lights on the dc panel or interior lights. Im looking for clues where to start looking. Starts and runs fine. I have no other history on the van. V2 does have the litheum batteries. I would think there would be some kind of power especially when plugged in. Ive been searching the forums but haven't come up with anything yet. Thanks.

Fyi, the EcoTrek system is only "smart" if it has at least 12V of DC power.

What is referred to in later post as a "kicker battery for the inverter", this battery is most critical for the EcoTrek to work. If that battery drops below 12V, it can't reset the lithium batteries. If under 12V, the Balmar does not find it as a battery to charge when you start up the vehicle or the generator assuming you are going to charge. If my rv has been sitting, I just put a one of those small 12V lithium packs on the battery when I start the engine. -- the Balmar then finds it, and then will charge it.

When the system uses lithium battery power, there are a few more quirks caused by the battery protection system built into the proprietary battery packs.

So then, the Battery Management System may have a lithium battery disconnect switch. If so, that shuts off the inverter. My EcoTrek system requires I leave switch on the inverter always on, and use the disconnect to shut off the inverter. (I have bumped mine off when loading luggage and it is the last place I looked to troubleshoot.)

On Shorepower, if the inverter is off, you won't get coach DC, nor battery charging. The inverter converts the 110V AC shorepower to DC for the coach, and for charging.
Also, if you don't connect shorepower in the right order, the 110V on the appliances like the fridge may not trigger to 110 AC, and and may continue to operate on 12V DC.

If the inverter is on, and you forget to use the battery disconnect switch, the inverter draws a few amps from the "kicker battery" when the lithium battery is off,. Draws down below 12V, again, it is a dead kicker battery.
The same happens if you leave stuff running and the lithium battery discharges, the inverter keeps powering everything, including all the DC items in use are now drawing power from the "kicker battery.

Hint, if you turn lithium on and then hold reset for 10-30 seconds you should hear a "thump" as the turn on. Same"thump" when you turn off or on the battery disconnect. IF YOU DON'T hear the thump, most likely the "kicker battery" is below 12V. No DC and the Balmar does not sense a battery, it won't charge it, even if you drive for hours......
2nd hint: if the lithiums battery is off, and you still register voltage on the guage, it is the voltage of the underhood "kicker battery'. If it is below 12V, nothing works as expected.

Summary, underhood "kicker battery" (mine is an AGM 12V, some units have two 6V) powers all of the Battery Management system computer logic in the Balmar, in the lithium batteries, and is the power source for the DC and inverter when the lithiums are off. It even powers the solar converter. I store my unit in a (dark) garage, and even with everything shut off and disconnected, the solar converter draws power from the underhood battery dropping it below 12V... .... and so, EcoTrek with lithium,

return to the beginning of this post because its time to repeat the discussion all over again. .

The moral of the story: Keep that underhood battery charged.

[mumkin]

One detail...

None of these EGHNA Promaster based units have a "underhood battery." Some have the "underhood generator" or larger second alternator, but none of them have any battery under the hood. The van battery is under the driver's feet.

The Kicker battery that backs up the Ecotrek system is hung under the rig towards the rear. (and yes, it is very important to keep it charged)

[starrski]

Agreed. I was commenting from the point of view of the Sprinter platform where the engine start battery is under the seat and the coach battery is under the hood.

Attached are two files sent to me from RoadTrek for the procedures:
a.) for typical "lithium start up" and
b.) for "dead lithium start up".

My experiences and frustrations are based on a 2018 RoadTrek with EcoTrek 400, Voltstart, and Solar options on the Sprinter chassis with the AGM battery under the hood. The concepts are the same for the other chassis setups with the lithium version of "EcoTrek."

The reality is that EcoTrek and Voltstart systems from RoadTrek 2018 and prior made by EHGNA are now marketed in the USA by RoadTrek.inc and Hymer USA, carry with them the quirks of their implementation of lithium ion technology.

Everything relies on fully charged batteries, and works best at " service shop temperature" (say 70 degrees F).
Also of importance, the lithium batteries are at full charge at about 14.4 volts, .... 12.4 volts ion the lithium batteries is somewhere less than 80% of fully charged.

Summary:
There is one EcoTrek start up/kicker battery that is critical and must be above 12V at all times for the systems to function. (mine goes dead if not used for a few days because of all of the components in standby drawing just a little power. (I have the habit now of putting a small 12V battery pack, that I carry to charge USB devices, on this AGM battery before I start up the RV.)

Repeating theme: Keep the AGM battery charged.above 12V.

[markopolo]

Originally Posted by starrski

............................Also of importance, the lithium batteries are at full charge at about 14.4 volts, .... 12.4 volts ion the lithium batteries is somewhere less than 80% of fully charged ................................................

For LiFePo4 (and lead acid) seeing 14.4V requires an active charging source to be present and it only part of what's needed to know that the batteries are fully charged. The other part is the amount of current being accepted. For example. 14.4V with 50A current still being accepted is not a fully charged battery for either chemistry.

Fully charged LiFePo4 cells in 4S configuration common in RV's at rest will be a high as 13.6V+

A LiFePo4 battery at 12.4V in a resting state is depleted. Nearing 0% usable energy remaining.

Look at Winston's SOC data here: https://www.classbforum.com/forums/f...tml#post101871 and updated here: https://www.classbforum.com/forums/f...tml#post103586

or mine here: https://www.classbforum.com/forums/f...tml#post107776

If there's much capacity left at 12.4V in an ecotrek system then it has to be coming from the appended AGM battery.

[starrski]

agreed. The system is complex and has many places where it can have trouble.
Just sharing the workarounds that I have found that work for my particular RV.

[markopolo]

It's great that you shared the PDF files and your use of a small 12V battery pack. That should help others.

From the PDF:

the lithium modules will have an inherent self-discharge due to the internal relays and electronics of between 5 and 10 Amps per hour that will continue to drain them (Battery Management System). While the solar may be able to keep up with this during the day (depending on variables), at night they continue to discharge.

That's a lot of energy lost. 120Ah to 240Ah per day. 400W to 800W solar needed just to cover the self-discharge (on sunny days).

Someone is bound to come up with a fix for that. Tremendous system gain if that problem is solved, as much gain as adding 400W to 800W solar!

Are you able to measure the current draw on the 12V AGM when your RV is parked in your garage?

Seems that adding a Trik-L-Start, in reverse order - yellow wire to starting battery & blue wire to the 12V AGM kicker battery would charge/boost the kicker battery whenever the van engine is running. That would bring the voltage up on the 12V AGM kicker battery enough to satisfy both the Balmar unit and the LFP startup relays.

[mumkin]

I don't think Hymer (now Thor) is using the Ecotrek system are they? Of course when EGHNA was building Hymer they were. (this is sooo confusing for all) I haven't paid any attention to what Thor is doing with its Hymer products.