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

[markopolo-ClassB]

NEC 2008:Table 250.122
Minimum Size Equipment Grounding Conductors for Grounding Raceway and Equipment

That would not seem to apply to how you're using that run of 6 AWG.

In an RV you'll typically see the following over current protection:
15A with 14 AWG
20A with 12 AWG
30A with 10 AWG
40A with 8 AWG
50A with 6 AWG
Etc.

That makes me all the more curious about the full intended use of the original line with the 150A breaker on it. I don't see it in the before schematic. Was it / is it used to boost an LFP module for example? What size AWG wire was 150A breaker protecting originally?

What are the triggers to take the C+ & D+ terminals offline? Is it low temperature, high voltage, high temperature, low voltage for for both but at different setpoints?

 

[ContinuousImprovement]

That would not seem to apply to how you're using that run of 6 AWG.

That makes me all the more curious about the full intended use of the original line with the 150A breaker on it. I don't see it in the before schematic. Was it / is it used to boost an LFP module for example? What size AWG wire was 150A breaker protecting originally?

What are the triggers to take the C+ & D+ terminals offline? Is it low temperature, high voltage, high temperature, low voltage for for both but at different setpoints?

We are asking lots of Aktiv owners to change there wiring so these are good questions.
1) The NEC is always clear that grounds must always be equal or greater than Hot and Neutral so 6awg is ok for all conductors. BTW: I find it interesting that Canadian electrical code does allow ground to be one size small.
2) convenance and commonality is one explanation for the 150amp CB. Two of the same CB are used elsewhere on the Aktiv.
3) my observations are that the KS2 battery opens the discharge side due to overcharging on that side and cold.

 

[ContinuousImprovement]

RVIA LV is the controlling standard for RV DC wiring. They only offer it in paper. so it will take time to arrive to our RV. Does anyone have a copy and what is the maximum current allowed on 6-awg wire?

 

[booster]

We are asking lots of Aktiv owners to change there wiring so these are good questions.
1) The NEC is always clear that grounds must always be equal or greater than Hot and Neutral so 6awg is ok for all conductors. BTW: I find it interesting that Canadian electrical code does allow ground to be one size small.
2) convenance and commonality is one explanation for the 150amp CB. Two of the same CB are used elsewhere on the Aktiv.
3) my observations are that the KS2 battery opens the discharge side due to overcharging on that side and cold.

Unless things have changed, as I haven't had to deal with it for a while, I think NEC allows undersized grounds in some places, particularly with large conductors in use. Underground feeders and bond to earth grounds, I think, were two of the places, IIRC. I think in the past, there was 12ga Romex that had 14ga ground wire, and they had two versions of 12ga. One was labelled "full size ground" or such.

 

[ContinuousImprovement]

I was wrong. RVIA-LV (Low Volt) standard. The circuit breaker for the 6-awg wire is now 70 amps. I also added the existing 50amp fuse to the figure.
https://sites.google.com/view/suiet-hacks-llc/rewiring-aktivs-ecotrek-system?authuser=0

 

[chris_g19]

This is Rev H

Just cracked it open. Going to make a schematic.

Build quality is much better than I expected honestly, real organized, nice battery heaters. Can't wait to test the cells. Hopefully they are good and it's just the BMS that got fried. Few hundred bucks can fix this mess, but I'll be paying more than that in labor. Oh well, it's fun, and if I can post my fix experience maybe some others will attempt it too.

Probably will change it from a 4S2P system to a 2P4S so one balancer and monitor can be used for all 400AH.

And of course, add Bluetooth so I can keep a close eye on performance.

 

[markopolo-ClassB]

Are the heaters in between the cells?

The cells look like these: https://www.aliexpress.com/item/4pc...0A-100ah-for-EV-solar-energy/32838532219.html

so around $2,000 of cells in the 400Ah system

 

[chris_g19]

Yeah, that's about right. I'll get into lots of detail with the components this week.

Yeah, that's the battery heaters there. I think I might hold up a manual control switch for them since I rarely get into cold weather. I'll have the battery temp sent to my phone, so manual control would make good sense. I'm a control freak anyways haha.

 

[gregmchugh]

Can you determine if the battery heaters were controlled by a simple thermostat circuit or were controlled by the BMS?

 

[chris_g19]

Yes for sure. That's easy. I'll play more after work.

 

[markopolo-ClassB]

Just for info:

50 packs are $150 each so $600 wholesale for 200Ah at 12V ............ ( https://www.alibaba.com/product-detail/3-2V-200Ah-Lithium-Iron-Phosphate_60687572989.html )

It would be useful to find a detailed specification sheet.

 

[chris_g19]

Yeah. I think the majority of us are not going to need to replace the cells though. These things should last many years. I think it's something else that failed, probably the BMS. I tested my cells and they are all perfectly in balance and about 80% SOC. I don't even think I'm going to bother doing a load test until I get everything else replaced and upgraded, I'm so confident the cells themselves are just fine.

 

[gregmchugh]

Yes for sure. That's easy. I'll play more after work.

I am just curious on how they were controlled since they seemed to be capable of operating when the BMS may have been off.

 

[chris_g19]

I'll check soon, but I'm pretty sure the BMS doesn't really turn off. It just allows charging/discharge or not. You never want to battery watchdog to stop protecting the battery. So could be either.

If I can't tell from the wiring, we may never know, because whatever they have in there I'm going to trash and replace with something top of the line with Bluetooth diagnostics.

 

[booster]

I wonder if something like this could just be easily used and get rid of all the Roadtrek BMS problems, parasitic, multiswitch etc.


https://www.elitepowersolutions.com/bms


on edit;


Or even better a one piece soltution?


https://www.elitepowersolutions.com/ibcs

 

[gregmchugh]

I wonder if something like this could just be easily used and get rid of all the Roadtrek BMS problems, parasitic, multiswitch etc.


https://www.elitepowersolutions.com/bms


on edit;


Or even better a one piece soltution?


https://www.elitepowersolutions.com/ibcs

ARV used them so they must be good...

Seriously, they make high quality stuff but I get the feeling that the DIY folks prefer something that is cheaper and more hackable...

 

[chris_g19]

Yeah. There are a few aftermarket BMS that will work well. I like the Smart 123 BMS made by some guys in the Netherlands.

Pulled a cell. Doesn't really have much for identify marks on it, but not a big deal. These things are all made in the same factory under different brand names.

2 heaters, 20 watts each

 

[chris_g19]

Found the BMS, they using some weird thing I've never seen. Probably low cost and cheap.

I bet this is the failing component.

 

[silverchris]

Looks like a CALB cell to me, from my research when I was buying some lifepo4 cells

 

[avanti]

Found the BMS, they using some weird thing I've never seen. Probably low cost and cheap.

I bet this is the failing component.

Mewyeah DKX906