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

[avanti]

What are the plusses?

[booster]

Originally Posted by avanti

What are the plusses?

I would guess that the big one would be battery longevity based on what we have heard of the desirability of no float or sitting at full all the time. If the batteries were good at a float or holding of charge voltage, there would be no reason not to do it, I would think. It many also be better for the AGM is the charge sources go off or to float, too, depending on voltage.

[ContinuousImprovement]

Originally Posted by gregmchugh

In any case, while I am aware that you justifiably have major issues with EHGNA and Jim Hammill, how was the 6 year warranty fictional prior to the point where EHGNA went kaput?

A warranty must bank 5% to 10% of the BOM cost compounded for each year of warranty passed year-one. The precent is chosen based on the MTBF of the components. That formula falls apart if the warranty extends beyond any component's MTBF "bathtub", which is the case for the relays and LiFePo4 cells.

6-years was also doomed since the warranty fund calculation assumes thorough testing already rang out the latent design defects. Clearly testing was left to the customers.

[gregmchugh]

Originally Posted by ContinuousImprovement

A warranty must bank 5% to 10% of the BOM cost compounded for each year of warranty passed year-one. The precent is chosen based on the MTBF of the components. That formula falls apart if the warranty extends beyond any component's MTBF "bathtub", which is the case for the relays and LiFePo4 cells.

6-years was also doomed since the warranty fund calculation assumes thorough testing already rang out the latent design defects. Clearly testing was left to the customers.

All true except in this case the warranty was simply a marketing tool unrelated to actual future costs for warranty coverage. It is pretty clear that EHGNA was not doing business in a financially sound manner isn’t it?

[Davydd]

Originally Posted by gregmchugh

All true except in this case the warranty was simply a marketing tool unrelated to actual future costs for warranty coverage. It is pretty clear that EHGNA was not doing business in a financially sound manner isn’t it?

That goes without saying. They went under. Could be it was just a pyramid scheme gone awry by EHGNA management too soon before Thor finalized the deal.

[booster]

Originally Posted by gregmchugh

All true except in this case the warranty was simply a marketing tool unrelated to actual future costs for warranty coverage. It is pretty clear that EHGNA was not doing business in a financially sound manner isn’t it?

Many of us have considered the long Roadtrek warranty a marketing tool all along, I think.


The extended battery warranty started even before the lithium batteries were available and appeared to be a reaction to the very poor durability of the etrek AGM systems which was getting a lot of attention and pushback against Roadtrek and Jim Hammill even on the Facebook group. They put in the warranty to try to quiet things down and not kill off sales, which it appears to have worked. The warranty carried on to the lithium systems and expanded to the coach parts as well.


With the well known high failure rate of the battery systems, and reduced coachwork quality, we saw happening, there were many questions raised about if the warranty claims would eventually cause financial issues for Roadtrek. As it turned out, the other bad financial stuff appears to have helped that happen to the point of totally killing off the company, most likely. (Isn't today the day we are supposed to hear something about the sell off?)

[avanti]

To be fair, ALL warranties are predominantly "marketing tools". Manufacturers offer them because they improve sales. That is pretty much the end of the story.

Folks tend to assume that the length of a warranty somehow reflects the quality of the product. This is not generally true. It is common for exactly the same product to be sold with different packaging and different warranties at different price points. It is purely an economic calculation, as the above-mentioned rule-of-thumb illustrates. It is perfectly feasible to offer excellent warranties on crappy products--it is just more expensive.

The problem occurs when the underlying economic model is flawed to the point where the promised services may not be deliverable. This can happen due to financial incompetence, fraud, or technical surprises. I will leave it to others to debate which of these apply here.

[BringBackRoadtrek]

Originally Posted by chris_g19

It will be $7,000 dollars to replace both my modules. They can't replace one because module Rev H isn't compatible with Rev G.

Not $7000. Buy a refurbished H and keep your G for parts. Share this dealer cost sheet and negotiate a fair markup from $450.
https://docs.google.com/document/u/4...E14ftBm863/pub

[chris_g19]

Ok, here I go.

Replacing my EcoTrek with a custom build. Reusing the same cells and battery box for a drop in replacement.

Attached is my super simple schematic. No relays, no battery heaters, virtually no parasitic draw.

Diagnostics via Bluetooth, and parameters programmable via Bluetooth, so I'll have tons of info to post here on the forum.

Expected to complete the project in 4 weeks.

[silverchris]

Originally Posted by chris_g19

Ok, here I go.

Replacing my EcoTrek with a custom build. Reusing the same cells and battery box for a drop in replacement.

Attached is my super simple schematic. No relays, no battery heaters, virtually no parasitic draw.

Diagnostics via Bluetooth, and parameters programmable via Bluetooth, so I'll have tons of info to post here on the forum.

Expected to complete the project in 4 weeks.

How much is the Smart BMS costing you? I just bought a REC Active BMS for my setup, which so far has seemed pretty decent and well built. Though I do have some parasitic draw from the relays (About 100mA with just one, so not too terrible.) I need to add up what I spent on the REC, but I believe it was about 600CAD shipped, and with customs fees/duty

[gregmchugh]

Originally Posted by chris_g19

Ok, here I go.

Replacing my EcoTrek with a custom build. Reusing the same cells and battery box for a drop in replacement.

Attached is my super simple schematic. No relays, no battery heaters, virtually no parasitic draw.

Diagnostics via Bluetooth, and parameters programmable via Bluetooth, so I'll have tons of info to post here on the forum.

Expected to complete the project in 4 weeks.

Looks good, does the BMS report accurate battery SOC or would it make sense to add a shunt and Victron Battery Meter to get SOC?

[chris_g19]

Originally Posted by silverchris

How much is the Smart BMS costing you? I just bought a REC Active BMS for my setup, which so far has seemed pretty decent and well built. Though I do have some parasitic draw from the relays (About 100mA with just one, so not too terrible.) I need to add up what I spent on the REC, but I believe it was about 600CAD shipped, and with customs fees/duty

It was $326 USD shipped from Germany. Google "123 smart BMS"

If you're up for it, get rid of those relays and go with FETs. 100mA for a relay, ~1mA for a FET, plus they will last a lot longer and are much more reliable. I'm using the Victron BP-100 and BP-220 which will take 600 amps peak.

My goal is to go all solid state if possible.

[booster]

Originally Posted by chris_g19

It was $326 USD shipped from Germany. Google "123 smart BMS"

If you're up for it, get rid of those relays and go with FETs. 100mA for a relay, ~1mA for a FET, plus they will last a lot longer and are much more reliable. I'm using the Victron BP-100 and BP-220 which will take 600 amps peak.

My goal is to go all solid state if possible.

What is the voltage drop on this kind of FET?

[silverchris]

Originally Posted by chris_g19

It was $326 USD shipped from Germany. Google "123 smart BMS"

If you're up for it, get rid of those relays and go with FETs. 100mA for a relay, ~1mA for a FET, plus they will last a lot longer and are much more reliable. I'm using the Victron BP-100 and BP-220 which will take 600 amps peak.

My goal is to go all solid state if possible.

I didn't realize those could be used that way. I was doing some looking for FET based switching, but couldn't find anything. I ended up grabbing a used Tyco Kilovac EV200AAANA for my load switch, and hadn't selected anything for my charging switch yet. Might be making some design changes now!

[cruising7388]

Originally Posted by gregmchugh

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.

When the charger is connected to the charge port, if the port senses a fully charged battery condition, it opens the port. Got that. The charger sees no load and consequently quits charging. But isn't the inverter/charger still powered up and why would the 120V pass thru path to the AC panel be inhibited? Even powered down, isn't the transfer relay normally closed?

[gregmchugh]

Originally Posted by cruising7388

When the charger is connected to the charge port, if the port senses a fully charged battery condition, it opens the port. Got that. The charger sees no load and consequently quits charging. But isn't the inverter/charger still powered up and why would the 120V pass thru path to the AC panel be inhibited? Even powered down, isn't the transfer relay normally closed?

The transfer relay only activates when the inverter is on. When the inverter is off it does nothing, no pass through, no battery charging, no inverting, nothing operates.

Well, the charger will see the AGM battery and charge it even if all the Ecotreks get fully charged and all disconnect the cells from the charge ports.

As long as the inverter is on and connected to shore power then the transfer relay will activate and pass the shore power through to the van.

When inverter was on the load side there was the issue that when all the Ecotreks were disconnected from the load port there was nothing connected to the shore charger and the 12v output was very unstable. Transfer relay was still sending shore power to the van.

[cruising7388]

Originally Posted by gregmchugh

The transfer relay only activates when the inverter is on. When the inverter is off it does nothing, no pass through, no battery charging, no inverting, nothing operates.

Well, the charger will see the AGM battery and charge it even if all the Ecotreks get fully charged and all disconnect the cells from the charge ports.

As long as the inverter is on and connected to shore power then the transfer relay will activate and pass the shore power through to the van.

When inverter was on the load side there was the issue that when all the Ecotreks were disconnected from the load port there was nothing connected to the shore charger and the 12v output was very unstable. Transfer relay was still sending shore power to the van.

I have to be continually reminded that this inverter has to be on for the charger to operate I don't recall this necessity for my Magnum or Xantrex Prosine 2.0 units. While they were physically integrated, they were electrically independent.

I see that if the inverter/charger is directed to the battery charge port and if this port opens, the charger is still common to both the AGM battery and the 12V distribution panel. Switching the connection to the discharge port does isolate the AGM from the charger if the battery is shut off, but doesn't the charger still see the 12V panel? Why wouldn't the loads from this panel load keep the charger in a stable condition like other modern converters that are typically designed to deliver stable voltage even in the complete absence of a battery? I know that vintage converters (Magnetek 60xx?) needed a battery present because it was necessary for reducing AC ripple to acceptable levels, but at this point isn't this antiquated design ancient history?

[gregmchugh]

Originally Posted by cruising7388

I have to be continually reminded that this inverter has to be on for the charger to operate I don't recall this necessity for my Magnum or Xantrex Prosine 2.0 units. While they were physically integrated, they were electrically independent.

I see that if the inverter/charger is directed to the battery charge port and if this port opens, the charger is still common to both the AGM battery and the 12V distribution panel. Switching the connection to the discharge port does isolate the AGM from the charger if the battery is shut off, but doesn't the charger still see the 12V panel? Why wouldn't the loads from this panel load keep the charger in a stable condition like other modern converters that are typically designed to deliver stable voltage even in the complete absence of a battery? I know that vintage converters (Magnetek 60xx?) needed a battery present because it was necessary for reducing AC ripple to acceptable levels, but at this point isn't this antiquated design ancient history?

Yes, it is a stupid design to not have the two functions separate...

The 12v distribution is on the load side, not the charge side so it is isolated from the AGM and the battery charger when the inverter is on the charge side.

There are converters that require no battery to provide a stable output and there are chargers that require a battery connected to provide a stable output.

Converters can provide a regulated voltage without the need for connection to a battery but they can also be connected to a battery to charge it.

Chargers typically require a voltage reference from a connected battery in order to get a stable output voltage (loads wouldn’t help here). Without the battery connection and just loads there is an unstable voltage output from the charger.

[cruising7388]

Originally Posted by gregmchugh

Yes, it is a stupid design to not have the two functions separate...

The 12v distribution is on the load side, not the charge side so it is isolated from the AGM and the battery charger when the inverter is on the charge side.

There are converters that require no battery to provide a stable output and there are chargers that require a battery connected to provide a stable output.

Converters can provide a regulated voltage without the need for connection to a battery but they can also be connected to a battery to charge it.

Chargers typically require a voltage reference from a connected battery in order to get a stable output voltage (loads wouldn’t help here). Without the battery connection and just loads there is an unstable voltage output from the charger.

With the charger connected to the battery charge port, is there a potential for continuous recycling?

1. The charge port senses full charge and opens the port.

2. The inverter shuts down.

3. The charger shuts down and shoreside 120V pass-thru is inhibited.

4. Unless there are active 12V external loads the system remains in this state
until the internal BMS demand drops battery voltage enough to reopen the
charge port.

5. Battery charging resumes at the charge port.

6. Inverter/charger 120V pass-thru to AC loads is restored.

7. The charge port senses full charge and opens the port.

8. Rinse and repeat.

[gregmchugh]

Originally Posted by cruising7388

With the charger connected to the battery charge port, is there a potential for continuous recycling?

1. The charge port senses full charge and opens the port.

2. The inverter shuts down.

3. The charger shuts down and shoreside 120V pass-thru is inhibited.

4. Unless there are active 12V external loads the system remains in this state
until the internal BMS demand drops battery voltage enough to reopen the
charge port.

5. Battery charging resumes at the charge port.

6. Inverter/charger 120V pass-thru to AC loads is restored.

7. The charge port senses full charge and opens the port.

8. Rinse and repeat.

I am not familiar enough with the RT inverter/charger but what caused the inverter to shut off when the charge ports all disconnected?

I think it will continue to operate with the transfer of shore power to the van and the AGM battery connected to the charger until at some point the BMS reconnects the charge port some of the Ecotreks as they discharge from the 12v loads (and in some vans the secondary inverter for the kitchen which is connected to the load side of the Ecotreks) to the point where the BMS reconnects.