Life after RoadTrek: Ecotrek, rebuild Ecotrek module, or DIY?

[booster]

I don’t recall any reports where both connections were not used. There were cases where the two connections were jumpered together, for example, the instructions that came with the free Ecotrek module offer that was installed by a dealer in an existing AGM van showed a jumper across the two connections. It is possible that these modules had a special firmware version designed for this configuration.

I think that is probably what I remembered. There seemed to be a lot of talk at the time about why they needed separate connections in the first place. A lot of that kind of discussion was around the time when they decided to add the AGM to address all the activation and voltage reference stuff concerning locked out lithium modules, I think.

 

[Joebecky]

I don’t recall any reports where both connections were not used. There were cases where the two connections were jumpered together, for example, the instructions that came with the free Ecotrek module offer that was installed by a dealer in an existing AGM van showed a jumper across the two connections. It is possible that these modules had a special firmware version designed for this configuration.

If the two connections are jumpered together, it would have to be internal. Does anyone else with the Axion have only the charge and ground with cables to them? The set up may be due to either cost or space limitations? It does seem to work so far, though I did have a problem with the Balmar regulator (MC-614) that I ended up replacing (no fun, in the winter, in the driveway and on my aching back).

 

[Joebecky]

I think that is probably what I remembered. There seemed to be a lot of talk at the time about why they needed separate connections in the first place. A lot of that kind of discussion was around the time when they decided to add the AGM to address all the activation and voltage reference stuff concerning locked out lithium modules, I think.

I am not sure I have an additional AGM. There is a box next to the rear axle but can not tell for sure if there is anything inside. Cables go back in that direction, but I thought it was to supply power to the macerator pump for the black/gray tank. I will look closer when spring gets here. To restart the Lithium batteries, instructions, I believe, say to start the GU.

If the Power Batteries Will Not Turn On
Start the engine. Turn on the EcoTrek Power Batteries. Allow about 30 seconds for the batteries to start. If necessary, press and hold the Reset button on top of the panel. Once the batteries are on, plug into shore power if desired (to perform this, the inverter must be on) and turn off the engine.
When not in use, turn the Power Batteries off. When storing the Power Batteries for extended periods, lithium batteries should be stored at about half state of charge, about 13.1V resting voltage.

Of course, don't know which version of Eco Trek this applies to?

 

[booster]

I am not sure I have an additional AGM. There is a box next to the rear axle but can not tell for sure if there is anything inside. Cables go back in that direction, but I thought it was to supply power to the macerator pump for the black/gray tank. I will look closer when spring gets here. To restart the Lithium batteries, instructions, I believe, say to start the GU.

If the Power Batteries Will Not Turn On
Start the engine. Turn on the EcoTrek Power Batteries. Allow about 30 seconds for the batteries to start. If necessary, press and hold the Reset button on top of the panel. Once the batteries are on, plug into shore power if desired (to perform this, the inverter must be on) and turn off the engine.
When not in use, turn the Power Batteries off. When storing the Power Batteries for extended periods, lithium batteries should be stored at about half state of charge, about 13.1V resting voltage.

Of course, don't know which version of Eco Trek this applies to?

A lot of the ecotrek stuff is still in the learning stage for all of us, as Roadtrek was so protective of the wiring and parts, especially inside the "magic box" and there are many different revisions besides.


The GU on the engine won't activate unless it sees a battery reference, unless they are doing something much different than we are used to, and that is what the AGM would do. Once running and active, the GU can take over to recharge the AGM and activate the ecotrek modules when you push the button. Of course this is all supposition as none of us know for certain at this point.

 

[gregmchugh]

I am not sure I have an additional AGM. There is a box next to the rear axle but can not tell for sure if there is anything inside. Cables go back in that direction, but I thought it was to supply power to the macerator pump for the black/gray tank. I will look closer when spring gets here. To restart the Lithium batteries, instructions, I believe, say to start the GU.

If the Power Batteries Will Not Turn On
Start the engine. Turn on the EcoTrek Power Batteries. Allow about 30 seconds for the batteries to start. If necessary, press and hold the Reset button on top of the panel. Once the batteries are on, plug into shore power if desired (to perform this, the inverter must be on) and turn off the engine.
When not in use, turn the Power Batteries off. When storing the Power Batteries for extended periods, lithium batteries should be stored at about half state of charge, about 13.1V resting voltage.

Of course, don't know which version of Eco Trek this applies to?

I guess a simple way to see if you have an AGM would be to make sure both Ecotreks are offline and then measure the voltage at some point, maybe at the solar controller since it is easy to access. Remove the negative cable for the battery connection at the solar controller and measure the voltage across the battery cables. If you get a voltage reading it should be the AGM battery.

 

[Joebecky]

I guess a simple way to see if you have an AGM would be to make sure both Ecotreks are offline and then measure the voltage at some point, maybe at the solar controller since it is easy to access. Remove the negative cable for the battery connection at the solar controller and measure the voltage across the battery cables. If you get a voltage reading it should be the AGM battery.

Crawled back under and had another look. Wish I had a garage with a pit like my father in law had. There is a heavy red and black cable going to the top of the box near the back axle, cannot see up there but it does look like there is another battery back there. Looks very difficult to access, I guess no maintenance required?

If you are charging both the lithium batteries and the AGM, how do you set the charge parameters (Lithium or AGM or in between)?

 

[gregmchugh]

Crawled back under and had another look. Wish I had a garage with a pit like my father in law had. There is a heavy red and black cable going to the top of the box near the back axle, cannot see up there but it does look like there is another battery back there. Looks very difficult to access, I guess no maintenance required?

If you are charging both the lithium batteries and the AGM, how do you set the charge parameters (Lithium or AGM or in between)?

There is a member here with the screen name ContinuousImprovement who has a website with info...


https://sites.google.com/view/suiet...1SXd1Si-ysACyQ76azBeIyLN9Lr35CIK6PgqJR5vyO3m8

There are also groups on Facebook if you do Facebook for owners and specifically for the Ecotrek system.

 

[cruising7388]

I am not sure I have an additional AGM. There is a box next to the rear axle but can not tell for sure if there is anything inside. Cables go back in that direction, but I thought it was to supply power to the macerator pump for the black/gray tank.

You should have an additional AGM battery and there should be a removable panel to access it. This AGM isn't there for the macerator. If the lithium batteries discharge to the point that the BMS shuts them down, the AGM provides stimulation to the BMS to emerge it from its coma when you hit the reset button.

 

[Joebecky]

You should have an additional AGM battery and there should be a removable panel to access it. This AGM isn't there for the macerator. If the lithium batteries discharge to the point that the BMS shuts them down, the AGM provides stimulation to the BMS to emerge it from its coma when you hit the reset button.

You are correct. I have not seen mention of this battery in any of the literature from EHGNA. I may not have looked in the right place.

 

[Joebecky]

You should have an additional AGM battery and there should be a removable panel to access it. This AGM isn't there for the macerator. If the lithium batteries discharge to the point that the BMS shuts them down, the AGM provides stimulation to the BMS to emerge it from its coma when you hit the reset button.

I do not see a removable panel in the van, but will keep looking. With the Axion, you may have to drop the battery? A somewhat complicated/confusing system for a non electrical engineer.

 

[gregmchugh]

I do not see a removable panel in the van, but will keep looking. With the Axion, you may have to drop the battery? A somewhat complicated/confusing system for a non electrical engineer.

I expect the design of the Ecotrek system would be confusing for even an electrical engineer...

 

[cruising7388]

I do not see a removable panel in the van, but will keep looking. With the Axion, you may have to drop the battery? A somewhat complicated/confusing system for a non electrical engineer.

Good point. Yes, the location and access to the AGM is likely model dependent. On our 210PC Etrek it's located in a compartment by the right rear tire that would normally house house AGM batteries so it has a removable panel which is good because there is no other way to check battery voltage. You may have to crawl under the coach to find it. At least it doesn't require watering.

 

[Joebecky]

Good point. Yes, the location and access to the AGM is likely model dependent. On our 210PC Etrek it's located in a compartment by the right rear tire that would normally house house AGM batteries so it has a removable panel which is good because there is no other way to check battery voltage. You may have to crawl under the coach to find it. At least it doesn't require watering.

Yes, each model has different constraints, and really good thing no watering required.
I wonder why they didn't use the coach battery to restart the Lithium batteries? Would probably want a switch so you only connect when needed. One less battery, reduced weight, and not faced with a difficult battery replacement in the future. Probably not as easy as I think. Just a thought.

 

[markopolo-ClassB]

Yes, each model has different constraints, and really good thing no watering required.
I wonder why they didn't use the coach battery to restart the Lithium batteries? Would probably want a switch so you only connect when needed. One less battery, reduced weight, and not faced with a difficult battery replacement in the future. Probably not as easy as I think. Just a thought.

Adding that AGM was probably the easiest way for them to provide a battery reference for the GU as Booster mentioned here: http://www.classbforum.com/forums/f...d-ecotrek-module-or-diy-8976-3.html#post90620

 

[booster]

I wonder why they didn't use the coach battery to restart the Lithium batteries? Would probably want a switch so you only connect when needed. One less battery, reduced weight, and not faced with a difficult battery replacement in the future. Probably not as easy as I think. Just a thought.

That same question has been asked many times on here


I think there are a few reasons that would make some sense.



I think that the primary one is that would be the most important would be the other side of the charging, as in what happens if the lithium suddenly shuts down when being charged by the alternator, shore power, or solar? If those sources suddenly lose a place for their output to go, even if the field of the alternator and charging control is shut down in the solar, you can get a very big voltage spike that could take out any electronics that are connected at the time, including the alternator, Balmar, solar controller, shore charger, and anything plugged into 12v in the van. Having the AGM there removes the chance of that happening. If the batteries are in cold shutdown the starting battery would have to stay on until the heaters allowed the lithium to come back on, which can be a while, so you would have to hold a button that long or have it on a timer.



Having the starting battery in the circuit all the time would violate a lot of new vehicle charging rules related to the computer controls and would also allow the starting battery to be accidentally discharged.


The AGM was a quick and effective way to handle the issue when they had all kinds of recovery issues, and probably some shutdown issues also as they did have a bunch of Balmar failures also (of course we still hear of quite a few of them now also).


ARV did not use an alternate 12v battery in their lithium setup and would use the residual power in the lithium bank to activate charging sources, which worked fine unless the batteries were in cold shutdown and you would have to get some external heat to the batteries to get them back online. They must have had a relatively foolproof shutdown of the lithiums that would shut off the field of the alternator and the charging sources ahead of the lithiums actually going offline, I think.



I don't think we have ever heard yet how Volta is doing it.

 

[wincrasher]

I'm not privy to the details of the programming, but I've observed that the Volta system shuts of all methods of charging when the battery bank outside it's protected range of operation. It controls the solar controller and will not allow charging above 90%. Same with the shore power and the alternator. Same with the safe band of allowed temperature.

 

[gregmchugh]

One of many issues with the inverter/charger used by EHGNA besides the lack of voltage profile control is that there is no separate control of the battery charger so to shut off shore charging you also will shut off the inverter pass through of the 120v to the van. They moved the connection around from the load side (no way to shut off charging and keep 120v power to the van) to the charge side (no way to keep 120v power when you shut off charging) but no way to do it the right way with that inverter/charger.

 

[cruising7388]

One of many issues with the inverter/charger used by EHGNA besides the lack of voltage profile control is that there is no separate control of the battery charger so to shut off shore charging you also will shut off the inverter pass through of the 120v to the van. They moved the connection around from the load side (no way to shut off charging and keep 120v power to the van) to the charge side (no way to keep 120v power when you shut off charging) but no way to do it the right way with that inverter/charger.

Is the "load side" the battery discharge terminal(s)? With the KS2 battery, aren't the charge and discharged terminals normally internally common?

 

[gregmchugh]

Is the "load side" the battery discharge terminal(s)? With the KS2 battery, aren't the charge and discharged terminals normally internally common?

There is an internal relay on both the charge and discharge terminals to allow the BMS to disconnect them from the battery cells. The original relays they used were suspected as being the source of the high internal parasitic load on the battery cells. The newer versions have much lower internal draw so they must have changed the type of relays used.

The BMS can disconnect the discharge terminal when the SOC is at the lower limit to prevent over discharge and can disconnect the charge terminal when the SOC is at the upper limit to prevent overcharging.

When the module is offline then both terminals are disconnected from the battery cells.

When both terminals are connected then everything is connected in parallel, the loads, the chargers, and the AGM. The inverter has been moved around, it seemed to be on the discharge side originally but has been moved to the charge side recently. Since it is both a load when it is inverting and a charger on shore power neither location is ideal.

 

[cruising7388]

There is an internal relay on both the charge and discharge terminals to allow the BMS to disconnect them from the battery cells. The original relays they used were suspected as being the source of the high internal parasitic load on the battery cells. The newer versions have much lower internal draw so they must have changed the type of relays used.

The BMS can disconnect the discharge terminal when the SOC is at the lower limit to prevent over discharge and can disconnect the charge terminal when the SOC is at the upper limit to prevent overcharging.

When the module is offline then both terminals are disconnected from the battery cells.

When both terminals are connected then everything is connected in parallel, the loads, the chargers, and the AGM. The inverter has been moved around, it seemed to be on the discharge side originally but has been moved to the charge side recently. Since it is both a load when it is inverting and a charger on shore power neither location is ideal.

The RT Etrek block diagram is attached. Some observations:

1. The alternator is hard wired to both the AGM and the lithium batteries so if the lithium batteries shut down or are disconnected the AGM still provides a load for the alternator.

2. The solar controller and the alternator are in parallel when charging all batteries. However, their charging voltages are not likely to be identical.

3. There is only a single feeder to handle both 12V charger output and 12V inverter input. Ideally, the charger should feed the battery charge ports and the inverter should be fed from the battery discharge ports.

4. The location of this single feeder from the inverter/charger has changed since initial production. It was originally connected to the battery discharge ports (blue lines). It was changed in later production to feed the battery charge ports (red lines). The explanation proffered for this is that when the charger was connected to the discharge ports, long term float charging could damage the batteries. Connecting the charger to the charge port presumably addresses this possibility because if the BMS recognizes a full SOC, it can shut down the charge port.