EcoTrek battery self-discharge rate?

[Luv2Go]

Regarding LiFePO4 battery storage at full charge, I read in an article somewhere that with this particular chemistry it did not matter whether you stored them at half or full charge, they do not degrade like some of the other lithium ion chemistries when kept at full charge. Unfortunately I can't find the article so can't link it.

My personal experience is much like davydd's, when I tested my Thundersky batteries at about four years old they still had over 110% of the rated capacity. At seven years when I sold it there was no noticeable degradation. I kept those batteries floating at about 3.45V per cell their entire life, the first year they floated at about 3.6V (per Thundersky recommendation)! I am floating my current pack at about 3.4V in the Roadtrek, and I leave it plugged in all the time.

The interesting thing is I'm now replacing the Thundersky pack in the RV I sold, they were killed by the current owner by accidentally NOT charging them over the winter!

So my opinion is, if the charging system is properly designed, to leave the coach plugged in all winter. I would expect Roadtrek's Ecotrek system to be properly designed, especially in 2019, which is about the 7th to 8th revision IIRC. Otherwise you'd hear about a lot more Ecotreks being replaced then I've heard of. JMHO and experience.

[arvitrekking]

I live in Michigan had this same question. I call RT last fall and they recommended to have the shore power plugged in, batteries on, and let the battery management system maintain the batteries.

[Davydd]

Luv2Go,

Thanks for corroborating my experience about keeping lithium batteries fully charged. All it takes is a 15a 120VAC source and you don't have to have a 30a sophisticated campground like source. Every home by code has that outside. Most people already carry a 30a to 15a adapter and extension cord. Unless you store remotely without a source of power it is not much of an inconvenience.

[Road_F'ed]

Anybody know what these are? 2018 Zion

https://scontent-ort2-1.xx.fbcdn.net...dc&oe=5D430696

[markopolo]

Looks like two breakers (black box like things) in parallel and they had to grind down the lugs to give some space. The red heat shrink covered things are probably just heavy gauge wire with lugs on the ends.

I don't know what that run is used for though.

[Road_F'ed]

No resets on the black boxes, I thought they might be terminal blocks. I also thought the red things were breakers or fuses. Some CB are automatic and do not have resets. Odd looking setup. Guess I could take off the heat shrink and see.

I get your logic might be cheaper to parallel breakers than to install just one large one.

Originally Posted by markopolo

Looks like two breakers (black box like things) in parallel and they had to grind down the lugs to give some space. The red heat shrink covered things are probably just heavy gauge wire with lugs on the ends.

I don't know what that run is used for though.

[GeorgeRa]

It seems as 2 circuit protection devices mounted on 2 junction blocks going nowhere, perhaps it is a prep option for a future addition. Being not protected and fully exposed they are likely on the ground side. It would be helpful to have a description tag attached.

[markopolo]

I just happened to have a breaker that looks just like those and I recalled that RT had used parallel breakers in Booster van so not unusual for them.


Klixon circuit breaker:

circuit breaker.jpg

[Road_F'ed]

I think you got it, checked and they do come in automatic reset 150Amp sizes. Some schematics show a 300 amp circuit breaker in that part of the circuit. But failed to mention how they pieced it together. Thanks very much for your help.

[GeorgeRa]

That is interesting and I must admit, I have never seen parallel CBs, new for me. If there is a difference in resistance one would likely trigger first somewhere between 150-300A.

[booster]

Originally Posted by GeorgeRa

That is interesting and I must admit, I have never seen parallel CBs, new for me. If there is a difference in resistance one would likely trigger first somewhere between 150-300A.

Exactly right, George, and it is why parallel is generally not recommended by circuit breaker manufacturers. A resistance difference like from the connections or trip mechanims could cause an unbalanced amp flow though the pair and make one trip early, with second right behind it.



What might also be seen would be the actual trip point of the breakers being different within the tolerance of them one could go earlier. If the tolerance is a fixed amount of amps, rather than a percent of load the smaller pair could drop out earlier or later depending on what the mismatch is.


Combining the two breakers is not recommended as far as I know, unless the pair of breakers are factory assembled to match well enough to not have issues and the parallel connections are factory installed and tested. This is the way the smaller 40 amp silver can type auto reset breakers were in our Roadtrek, and I called the manufacturer to confirm that point. The said as long as the in and out had long studs and the jumpers were solid bars on shorter pins all was OK as they were factory assembled.


If someone at Roadtrek saw the OK version of parallel, it would certainly be possible they misunderstood and thought it was always permissible to stack the breakers and did it with off the shelf singles.

[GeorgeRa]

Originally Posted by booster

Exactly right, George, and it is why parallel is generally not recommended by circuit breaker manufacturers. A resistance difference like from the connections or trip mechanims could cause an unbalanced amp flow though the pair and make one trip early, with second right behind it.



What might also be seen would be the actual trip point of the breakers being different within the tolerance of them one could go earlier. If the tolerance is a fixed amount of amps, rather than a percent of load the smaller pair could drop out earlier or later depending on what the mismatch is.


Combining the two breakers is not recommended as far as I know, unless the pair of breakers are factory assembled to match well enough to not have issues and the parallel connections are factory installed and tested. This is the way the smaller 40 amp silver can type auto reset breakers were in our Roadtrek, and I called the manufacturer to confirm that point. The said as long as the in and out had long studs and the jumpers were solid bars on shorter pins all was OK as they were factory assembled.


If someone at Roadtrek saw the OK version of parallel, it would certainly be possible they misunderstood and thought it was always permissible to stack the breakers and did it with off the shelf singles.

Thank you for reply, what are these 2 things, have part numbers, fuses? They don't look like solid copper connections.

[booster]

Originally Posted by GeorgeRa

Thank you for reply, what are these 2 things, have part numbers, fuses? They don't look like solid copper connections.

If I can read it correctly, it looks like it says "wire breaker", which may mean it is a fusible link.

[markopolo]

I think they're really short heavy gauge wires with lugs on each end with heat shrink applied over. Someone thought the lugs would be too close together and took a grinder to them to make them smaller.

[GeorgeRa]

This circuit would be weird with either cables/lugs or fusible links, it would cost more than a single 300A CB, and functionality would likely be not as good.

[booster]

Very odd, as Marko said they do look like the other lugs, ground for clearance so could be just a cable.



I blew them up and they actually say wire brk/brk and also 4/0 on them. They also have a CSA label on them that would infer some kind of testing on them.


If the parts on each end really are breakers, then these would be just parallel connections and maybe from the breaker manufacture based on the CSA labels, but could also could be final assembly testing of the area that had been run through CSA so all the parts have to be identifiable.


I have seen a lot of stuff on our Roadtrek that probably came from a test setup during product design or redsign and would normally have been "cleaned up" for production. Perhaps that is how the setup was born, but of course it could actually be cheaper than on big breaker, too.

[GeorgeRa]

It seems as Roadtrek needed an auto reset 300A CB which could be difficult to find, so I look and here it is from Del City folks. I am going tangent off this thread, sorry.

[markopolo]

Sometimes topics go where they have to go.

I don't think that the CSA # in this example indicates any specific testing or suitability.

I see this in the Class Description - https://www.csagroup.org/testing-cer...?class=5852-01

Wiring harnesses are not specifically investigated with regard to the ampere/voltage ratings of the wire and components unless uncertified components are involved. These aspects are the responsibility of the end user.

and this under the Certification Record - https://www.csagroup.org/testing-cer..._0_000-5852-01

Certified cables and Certified flexible cords and also consisting of various lengths of these wire, cut, stripped and/or semi-stripped without additional components, to customer's specifications.

for Applied Wiring Assemblies Inc. (on the EHGNA creditor list)

Some of the wiring photos here - Applied Wiring Assemblies Inc - look very similar to the photo posted earlier.

[booster]

Originally Posted by markopolo

Sometimes topics go where they have to go.

I don't think that the CSA # in this example indicates any specific testing or suitability.

I see this in the Class Description - https://www.csagroup.org/testing-cer...?class=5852-01


and this under the Certification Record - https://www.csagroup.org/testing-cer..._0_000-5852-01


for Applied Wiring Assemblies Inc. (on the EHGNA creditor list)

Some of the wiring photos here - Applied Wiring Assemblies Inc - look very similar to the photo posted earlier.

Sure looks like that is where they came from, certainly makes sense to farm out things like cables for many reasons.


I just noticed when I looked at the pix again for Roadtrek assembly. I think part of the reason it looks so odd is that one of the cables is likely attached to the wrong end of the short cable.


I would be relatively certain that to keep the voltage drop and thus current even in each of the breakers the in and out should be on each end so each breaker sees the resistance of of one of the small cables. The way it is one breakers sees neither of them and one sees them both.

[RossWilliams]

The original post here essentially raised the question of which was better, storing the batteries with a continuous charge, reducing the charge to 50% and risking them discharging completely or storing the batteries at a higher charge.

You have a complex system with both AGM and lithium batteries and limited real world experience available for a relatively new system. Optimal theory says the AGM battery is going to do better fully charged, the lithium better charged at 50% and there should be no parasitic draws. I think it is a mistake to make optimal the goal here. The real risk is that you seriously damage a battery by letting it fully discharge.

For three months, perhaps the best way to avoid that would be to leave it on the charging system that was designed to maintain the charges. If you don't trust the charging system, then leaving the batteries fully charged and hoping that they will survive whatever parasitic draws exist would be the other option. Wait until you can monitor the batteries and have real world results before you try to optimize how you handle storage.

You could also check out the "Roadtrek E-Treks & Ecotreks" group on Facebook. There are lots of people there with real world experience specifically with these systems. They might be able to give some guidance on storage.