Ecotrek tandem AGM Lifep04

[markopolo]

Here's a report of an Ecotrek 200 Lifep04 module being added to an existing AGM battery powered 2015 CS Adventurous:

https://www.facebook.com/groups/road...7306536761663/

There was an incentive offer last year.

It's good to see folks are getting them and it's going to be interesting to read reports of the setup and performance.

[gregmchugh]

Originally Posted by markopolo

Here's a report of an Ecotrek 200 Lifep04 module being added to an existing AGM battery powered 2015 CS Adventurous:

https://www.facebook.com/groups/road...7306536761663/

There was an incentive offer last year.

It's good to see folks are getting them and it's going to be interesting to read reports of the setup and performance.

If you read the report in that post from the owner with the 800 amp hour Ecotrek CS, who is also here on the forum, his boondocking experience in Death Valley sounds similar to the boondocking experience of a certain Advanced RV owner we hear from regularly. Seem to have similar boondocking performance in both vans.

Roadtrek has always touted the ability to add the Ecotreks to current vans while keeping the AGMs in place. They just recently extended this capability by having AGMs in all Ecotrek vans

[markopolo]

Have you learned or heard much about the tandems?

My assumption is that it's a fully functional AGM setup that won't shut down from cold. The lifep04 module might shut down but you'd still have full function of the coach. I'd like to find out if that's what it is. Just curious - no interest in purchasing.

I think the Lifep04 setup just have the AGM for the benefit of the Lifep04.

It would be nice to know the difference between the AGM + Lifep04 and the Lifep04 + AGM rigs.

[gregmchugh]

Originally Posted by markopolo

Have you learned or heard much about the tandems?

My assumption is that it's a fully functional AGM setup that won't shut down from cold. The lifep04 module might shut down but you'd still have full function of the coach. I'd like to find out if that's what it is. Just curious - no interest in purchasing.

I think the Lifep04 setup just have the AGM for the benefit of the Lifep04.

It would be nice to know the difference between the AGM + Lifep04 and the Lifep04 + AGM rigs.

Good questions. Not sure yet if they wire both configurations the same or not. Would take some rewiring of an existing van with an Ecotrek added to reproduce the configuration of the Ecotrek factory system. If they do a simple parallel battery drop in not sure how they handle the two separate 12 volt connections to the Ecotrek for charge and load which are tied together in the standard wiring.

Another puzzle to be solved by the dedicated group of Roadtrek armchair engineers, unrecognized by the establishment for their rigorous pursuit of scientific knowledge about the mysteries of Roadtrek electrical systems...

[booster]

It would be interesting to see the difference in how the AGM primary and lithium primary are setup, especially in how they charge and discharge them. The two styles o batteries take quite different profiles and equipment to be taken care of well, so there must be compromises. There was speculation early on that they were just paralleled in, but then they took them off the market for a while, so that could have changed to be wired like the lithium primary systems.

Now that Roatrek appears to be over the hump of getting the lithiums to function in use, it will interesting to see how they do over time. Tesla found out that the AGM in their cars took a real beating, with many of them not even lasting a year, so Roadtrek may have similar things happen. Time will tell, and least the AGM is the cheapest part of the system and should be on the 6 year warranty.

[gregmchugh]

Based on the installation instructions, the add on Ecotrek is simply wired in parallel with the existing AGMs and the two 12 volt connections on the Ecotrek are connected together with a short cable.

If you have not seen this you might find it interesting...

http://www.battcon.com/papersfinal2005/ngpaper2005.pdf

[booster]

Originally Posted by gregmchugh

Based on the installation instructions, the add on Ecotrek is simply wired in parallel with the existing AGMs and the two 12 volt connections on the Ecotrek are connected together with a short cable.

If you have not seen this you might find it interesting...

http://www.battcon.com/papersfinal2005/ngpaper2005.pdf

Interesting article, wish they had done AGMs also, though.

It seemed to do what would be expected, with the lithium doing most of the work early on. I was a bit surprised the the very initial discharge came from the wet cells, so they went down a little.

In the application they used, they have few discharges and very long times on float, so the wet cells would stand a better chance of getting back full. It would certainly change a bunch on repeated cycling every day.

They did say that both batteries need to have similar charge and float voltages, and that might be an issue as some say lithium should not be floated, and the lithium would probably be at a higher voltage than the lead acid battery at rest.

Trying to make both types see conditions to maximize their life is an interesting exercise, I am sure, especially if there is a constant voltage charger on the system that probably would be too high for lead acid batteries for long perionds.

Time will tell, though.