Roadtrek Ecotrek update

[Cannuck]

I’ve read about a lot about people on this forum (including us) that weren’t impressed with the phantom loads on the Ecotrek battery system. The phantom loads were crazy high (4-6 amps). They aren’t any more.

Roadtrek have a new generation of Ecotrek modules out where they’ve reduced the phantom loads to 0.3 amps.

[booster]

Originally Posted by Cannuck

I’ve read about a lot about people on this forum (including us) that weren’t impressed with the phantom loads on the Ecotrek battery system. The phantom loads were crazy high (4-6 amps). They aren’t any more.

Roadtrek have a new generation of Ecotrek modules out where they’ve reduced the phantom loads to 0.3 amps.

Interesting, where is that information from? Anyone tested it yet? If that is accurate, that would be a big plus for them compared to what they have had.

[markopolo]

If true then the parasitic loss would be up to 20 times less. It's where it should have been at the beginning.

Maybe competition is motivating them to improve. Winnebago seems to have leap-frogged past them. Even Winnebago's warranty on the Pure3 Energy lithium system bests Roadtrek at 8 years vs 6 years!

Hopefully previous Ecotrek purchasers will have an upgrade path made available to them. You could say they pretty much funded the experiment and it would be nice if they benefited from the up to 20 times parasitic loss improvement if this information is accurate.

[booster]

If some of us have the appearance of skepticism, it is mainly because there is some (plenty?). Roadtrek has a history of giving out false and misleading information in the past, particularly about electrical systems and batteries, over quite few years. We have even heard of reduced parasitic load on the Ecotrek modules in the past, that appears to not have been true, or at least not as large a reduction as claimed, as it still appears to be there. The claims are very hard to verify on the Ecotrek systems because of the complete lack of accurate battery state of charge monitoring. The claims are usually verbal at a show, or maybe an offhand Facebook group post, so no real spec release.


The assumptions (and guesses) on this forum as to the cause of the issue and how easy or hard it would be to fix have mostly focused on the internal relays used in modules to control input and output, which is likely correct but unproven. Fixing it probably should really not have been a big problem, but it has gone on for years so maybe is something more difficult.



AFAIK, nobody else has this level of parasitic loss in their lithium systems, so it isn't rocket science.

[cruising7388]

Originally Posted by booster

The claims are very hard to verify on the Ecotrek systems because of the complete lack of accurate battery state of charge monitoring.

Since the drain is internal in the BMS it never passes through the shunt so how can a SOC meter quantify it?

[booster]

Originally Posted by cruising7388

Since the drain is internal in the BMS it never passes through the shunt so how can a SOC meter quantify it?

If our assumptions about the relays using most of the power, they can easily be separated from the rest of the controls. I think Lithionics shows them that way in a couple of the pix on their site, IIRC. That would just leave the BMS proper to account for any power use, and my guess would be that it would use a relatively constant amount of power when it is active. Even if it was variable power use based on battery output, it could pretty easily built into the monitor programming. I have seen that one of the monitors currently available, don't remember which it is, has a setting for "self discharge" in % of battery capacity which is intended for lead acid batteries when they are in storage, so I would think it must not be too difficult especially since the other brands don't seem to have any problem with real monitors on their lithium systems.

[markopolo]

Is RT still using the relatively small capacity 200A modules and a switch for every module? If so, doing away with that concept would be an additional way to reduce parasitic loss.

.3A x 8 modules for example is still a 2.4A loss. That's 58Ah per full day so I guess those rigs still need multiple manual switches for end users to keep the losses under control.

[booster]

Originally Posted by markopolo

Is RT still using the relatively small capacity 200A modules and a switch for every module? If so, doing away with that concept would be an additional way to reduce parasitic loss.

.3A x 8 modules for example is still a 2.4A loss. That's 58Ah per full day so I guess those rigs still need multiple manual switches for end users to keep the losses under control.

I agree, and getting rid of the switches would also get rid of the required user input, which really shouln't be needed on a high end system like these.

[cruising7388]

Originally Posted by booster

If our assumptions about the relays using most of the power, they can easily be separated from the rest of the controls. I think Lithionics shows them that way in a couple of the pix on their site, IIRC. That would just leave the BMS proper to account for any power use, and my guess would be that it would use a relatively constant amount of power when it is active. Even if it was variable power use based on battery output, it could pretty easily built into the monitor programming. I have seen that one of the monitors currently available, don't remember which it is, has a setting for "self discharge" in % of battery capacity which is intended for lead acid batteries when they are in storage, so I would think it must not be too difficult especially since the other brands don't seem to have any problem with real monitors on their lithium systems.

With a master BMS, the losses certainly could be programmed into a SOC meter designed for it, but with the RT multiple BMS system that permits turning discrete batteries on and off, it gets problematic particularly if there is just one shunt. And while mono-stable relay current is easily defined, the duty cycle isn't because with different conditions, some relays may or may not be energized, although with bi-stable latching relays, the duty cycle error would be negligible.

[booster]

Originally Posted by cruising7388

With a master BMS, the losses certainly could be programmed into a SOC meter designed for it, but with the RT multiple BMS system that permits turning discrete batteries on and off, it gets problematic particularly if there is just one shunt. And while mono-stable relay current is easily defined, the duty cycle isn't because with different conditions, some relays may or may not be energized, although with bi-stable latching relays, the duty cycle error would be negligible.

That is the point that is being made, ditch the multiple BMS and make the systems to size with one BMS and bistable relays, or at least relays after the shunt, which would be a single so the losses could be measured. All power measured except for a single BMS and maybe even that could be run through the shunt if designed carefully. It really can't be more work or cost to make the batteries stackable but with specific to size BMS than it is to add all the switches and wiring plus multiple BMS's.

[Cannuck]

Originally Posted by booster

Interesting, where is that information from? Anyone tested it yet? If that is accurate, that would be a big plus for them compared to what they have had.

We took our van in for a battery issue and they installed this upgrade. They told me the specs of the upgraded battery modules verbally so perhaps there is still room for some skepticism. It definitely works a bit differently. You no longer have to manually reset the batteries.

They were honest about the parasitic loads originally being 4 to 6 amps so I took their word at face value when they said it dropped to 0.3 amps. We will test it when we get a chance (at least 6 weeks from now) and pass along our findings. The most basic test would be to turn the fridge off and see if the solar raises the charge level.

[GeorgeB]

So there's hope that Roadtrek will finally fix their very problematic Ecotrek system. It's been 4 years of live R&D with the "help" of hundreds of frustrated customers.

It's not the opinion many Roadtrek dealers still have, recommending the AGM over the Lithium packages. See the dealer comment at 16:09

https://youtu.be/syOczMnnjHc?t=969

[markopolo]

Originally Posted by Cannuck

We took our van in for a battery issue and they installed this upgrade. They told me the specs of the upgraded battery modules verbally so perhaps there is still room for some skepticism. It definitely works a bit differently. You no longer have to manually reset the batteries.

They were honest about the parasitic loads originally being 4 to 6 amps so I took their word at face value when they said it dropped to 0.3 amps. We will test it when we get a chance (at least 6 weeks from now) and pass along our findings. The most basic test would be to turn the fridge off and see if the solar raises the charge level.

Do you know if the lithium setup still requires that spare AGM battery in the mix?

[Smith101]

Originally Posted by Cannuck

We took our van in for a battery issue and they installed this upgrade. They told me the specs of the upgraded battery modules verbally so perhaps there is still room for some skepticism. It definitely works a bit differently. You no longer have to manually reset the batteries.

They were honest about the parasitic loads originally being 4 to 6 amps so I took their word at face value when they said it dropped to 0.3 amps. We will test it when we get a chance (at least 6 weeks from now) and pass along our findings. The most basic test would be to turn the fridge off and see if the solar raises the charge level.

The solar will never raise the charge level of the lithium’s because it is connected only to the AGM which only drives the BMS period. Nothing else. Sounds rediculoud but that’s what they told me about my 2017 400 system.

[markopolo]

wpshivers describes the setup differently than that here: http://www.classbforum.com/forums/f8...html#post83565

A test would be to see if you can turn on lights or a fan with all lithium modules off. If you can turn on a light with all lithium modules off then that light would be powered by the AGM. That would mean that the AGM does more (or is able to do more) than just power the BMS.

[booster]

It does seem logical that the solar may be only connected to the AGM battery because all the lithium can be shut off. Having the solar not connected to any battery reference could damage the solar controller and anything else connected to it if has no battery reference and ballast. They likely would also not want the AGM to be able to be killed by running the coach as then they would not be able to restart the lithiums if in shut off condition. That whole scenario is definitely a cludge of band aids on unresolved design errors if that is how it is being done.

[markopolo]

It is kind of fascinating. The main thing though is that folks are enjoy their RV's & having fun.

[cruising7388]

Originally Posted by booster

It does seem logical that the solar may be only connected to the AGM battery because all the lithium can be shut off. Having the solar not connected to any battery reference could damage the solar controller and anything else connected to it if has no battery reference and ballast. They likely would also not want the AGM to be able to be killed by running the coach as then they would not be able to restart the lithiums if in shut off condition. That whole scenario is definitely a cludge of band aids on unresolved design errors if that is how it is being done.

In current production, the AGM battery is hard wired to the solar controller and the GU alternator. If the lithium battery is active the solar controller also looks at the lithium battery charge port.

[booster]

Originally Posted by cruising7388

In current production, the AGM battery is hard wired to the solar controller and the GU alternator. If the lithium battery is active the solar controller also looks at the lithium battery charge port.

That would certainly make sense, but would also allow the AGM to try to charge the lithium if the SOC was very low, possibly killing the AGM, I think.


I seem to remember someone saying that the lithium modules now have the charge and load terminals connected. Is that correct? If so, the solar would also be running the coach and charging the lithium, and connected to AGM, or do they disconnect the AGM when it is full?