Converting Roadtrek Agile from Ecotrek to AGM

[TerrierTude]

Msnomer, what is PSW?

[oilman]

Pure Since Wave Inverter...

[gregmchugh]

Originally Posted by TerrierTude

Msnomer, what is PSW?

Pure Sine Wave

[MaxCapacity]

I have a 2018 SS Agile, which after a few early repairs is functioning well. If the worse case scenario happens and my lithiums fail, AND I want to keep it long term, I would look at replacing them with Battleborn Lithiums. And if I was Battleborn, I would be looking at a conversion kit to do this.

[TerrierTude]

Based on the excellent advice on this forum, I'm looking to replace my inverter and my Ecotrek battery (both of which have been problematic) with best of breed components. My repair place is nervous about doing this. I get that it must be more involved than just removing one component and dropping in another, but what really is involved in making the swap of these two components?

[JohnnyFry]

Noting the InstantPot®: It does not draw 75 watts but closer to 1,200Watts (depending on size) and it has electronic controls which require a Pure Sine Wave inverter (which is probably what you already have). 1,200 watts would draw about 110-115 amps from the battery and use 55-60 Amp hours for a 30 minute run time.

[ponti33602]

FWIW - Having 2 EcoTreks I went into heavy learning mode since they closed down last week. Reading much on all the FB sites I am feeling that much of what is going on is bad configurations/installations as I try and piece info together.

Also, I am reading where you should only charge 1 battery at a time if you have Rev H batteries whether from the GU or being plugged in. L batteries just recently came out and have a shut-down feature.

I spoke with KS2 who manufactures the batteries for Roadtrek and they have shipped batteries to dealers directly. That is potentially hopeful news for those of us with these batteries.

Attached are the Balmar recommended settings from KS2. I learned how to check mine from a YouTube video and is very straight forward. It was also mentioned that some of the EcoTreks were simply set too high. It almost sounds like (optimist on my part I know) that much of this is installation rather than design.

Anyway, I will test my Balmar settings this weekend. I have attached the sheet from KS2 if anyone wants to look. He said this should be used for both the H and or L batteries.

Another member here got this from KS2 and I also contacted them as I had a few additional questions/clarifications.

[Daniii]

If the inverter is in the rear, there are likely heavy cables between the battery and inverter. That's where I attached the output from my Zamp controller and 160W semi flexible panels. 2015 SSAgile. AGM batteries. I am not convincer of the cost/benefit/hassle of Li batteries. In fact, I read where they are putting one AGM in the circuit with Li's, as a sort of surge suppressor.

[Billinnc]

Originally Posted by TerrierTude

If I am going to go through the expense of this process, I would like to have as many AGMs as are practical. That said, I am not an energy hog. I have never run my air conditioning and would prefer not to. I get by fine, even in the desert with the Fantastic Fan, open windows and Reflectix. I've never used the microwave and wouldn't if boondocking, but I might want to use an electric kettle. I also have solar lights that I prefer to use instead of the LEDs (solar gives a softer light). But I would like to have a day or two of reliable house power without running the engine. I do want to put on the inverter and cook something in my Instant Pot pressure cooker which draws 75 watts (and that cooks most things in under an hour). I'd also like to be able to charge phones and laptops. I seldom watch the TV, but would like the option of watching a DVD or two if I got bored at night boondocking. However, having to run the engine to power batteries once a day is not a dealbreaker. Since the rig is my car, even when boondocking, I'm usually driving somewhere to a trailhead, so that gets the job done. I have the EcoTrek 400 AMP hr lithium power module. I have a small AGM as well, but all it really does is charge up the Lithium. Also i have solar. I would like more power than this.

Could you tell me the model number of your pressure cooker that only draws 75 watts? Sounds like what I need but haven't found any with less than 700 watt draw.
Thanks

[Mfturner]

Specific to the InstaPot, it does not draw full power the whole cooking time in pressure cooking modes. My Kill-a-watt showed that it only drew full power until it was up to pressure, then it drew about 300mA for the rest of the time to run the electronics. Slow cooking or sautee modes would draw differently, I suspect slow cooking PWM's the power but I'd have to plug it all in to check.

For example, I could run the smaller 3 qt InstaPot on my MM612 Magnum inverter in the old camper, which is modified sine wave and spec'ed at 600W continuous. It drew about 700 watts for less than 10 min until it was up to pressure, which is more than the 600W continuous rating but under it's surge limit. The MSW output didn't seem to bother the InstaPot, and the smaller InstaPot was a great size for camping for the 2 of us, so we have it in our new camper as well.

[TerrierTude]

I have the tiny IP that draws 750 watts (could I have mistakenly left off the last zero). And, as a pressure cooker, it doesn't draw that much consistently. It will use full power to come up to pressure, but once there,drops down to lower draw.

[booster]

Originally Posted by Mfturner

Specific to the InstaPot, it does not draw full power the whole cooking time in pressure cooking modes. My Kill-a-watt showed that it only drew full power until it was up to pressure, then it drew about 300mA for the rest of the time to run the electronics. Slow cooking or sautee modes would draw differently, I suspect slow cooking PWM's the power but I'd have to plug it all in to check.

For example, I could run the smaller 3 qt InstaPot on my MM612 Magnum inverter in the old camper, which is modified sine wave and spec'ed at 600W continuous. It drew about 700 watts for less than 10 min until it was up to pressure, which is more than the 600W continuous rating but under it's surge limit. The MSW output didn't seem to bother the InstaPot, and the smaller InstaPot was a great size for camping for the 2 of us, so we have it in our new camper as well.

I think a Kill a Watt calculates based on a true sine wave, so the actual energy consumption could be somewhat different than actual for a modified sine wave. How much is hard to tell. Plus it doesn't take into account the inverter losses. It is best to monitor the DC power used from the batteries with a battery meter that reads in watt hours as amp hours will not be right on because of voltage drop at high loads and you would have to guess at the right voltage to calculate watts.

[CAS3]

Can you point me to the you tube video on testing the unit

[ponti33602]

Originally Posted by CAS3

Can you point me to the you tube video on testing the unit

https://youtu.be/df0JpbERGHk

[MobileCabin]

I am thinking of rewiring the 4 AGM in my Agile. There is a pair of 6v in front and a pair in the rear. Right now the 2 sets a tied together with a cable from rear (+) to front (+) and the (-) of each through the chassis. The inverter connects to the rear set and the cabin power from the front set (the sprinter also appears to feed into the front set).

The change I want to do is to make the standard connections on the diagonals. I will have to tie the (-) with a new cable and at least remove the chassis connection from one set. I will probably use the (+) in the rear near the inverter and then the (-) from the front as the diagonal connections. Now the question.

Which is better, run another cable from the front diagonal (-) to the inverter/charger or use the chassis as the feed to the inverter? Copper is a better conductor than the chassis metal, but the chassis has much more metal.

Thanks,
Pat

[booster]

Originally Posted by MobileCabin

I am thinking of rewiring the 4 AGM in my Agile. There is a pair of 6v in front and a pair in the rear. Right now the 2 sets a tied together with a cable from rear (+) to front (+) and the (-) of each through the chassis. The inverter connects to the rear set and the cabin power from the front set (the sprinter also appears to feed into the front set).

The change I want to do is to make the standard connections on the diagonals. I will have to tie the (-) with a new cable and at least remove the chassis connection from one set. I will probably use the (+) in the rear near the inverter and then the (-) from the front as the diagonal connections. Now the question.

Which is better, run another cable from the front diagonal (-) to the inverter/charger or use the chassis as the feed to the inverter? Copper is a better conductor than the chassis metal, but the chassis has much more metal.

Thanks,
Pat

The goal is to have the cable resistance the same in each pair of batteries that are wired in series to get 12v. I assume two 6v in the front and two 6v in the rear. The coach being powered from one end and the inverter from the other is an issue if you want to get even lengths, though.


One way to do it would be:


Connect one of the rear - to one of the front +


Connect the other rear - to the other front +


This means two cables from front to rear of large size which would be 1/2 of the max inverter draw on each cable


Connect both of the front - to the chassis ground


Connect both rear + to the inverter with equal length cables


Connect inverter - to chassis


Connect any loads running on the current front batteries and/or alternator charging with a third cable connected to the inverter +. It would be sized for max current draw on the front or max charging from the alternator.


It is two extra cables front to rear, but it would give you a near perfectly balanced system, I think.

[MobileCabin]

Booster,

I like that way.

Thanks,
Pat

[MobileCabin]

Booster, one more question. If I added a shunt, should it be between the front 2 (-) and the chassis?

[booster]

Originally Posted by MobileCabin

Booster, one more question. If I added a shunt, should it be between the front 2 (-) and the chassis?

That would be the logical place to do it, for sure. Two equal length from the batteries to one side and a short single of bigger size to the chassis.


Do try to get the shunt into the coolest and cleanest area you can though, like behind a cutout in the grille area that lets some air in. Best to have them in the van, but tough in this case without a lot of extra cable.


In the rear you might want to simplify wiring by using two short equal length positives to a binding post from the batteries plus and include the alternator charging and van loads cable to it also. Then a single larger cable to the inverter.

[booster]

It is likely that someone will point out or ask about charge and discharge voltage issues in a system like proposed for MobileCabin, and it is a very valid question, IMO.


When you have a long cable between the two 6V batteries you have introduced a voltage drop that shows up between them in an area that is nominally 6V, not the 12V of the system or charger, so your actual charging voltage is whatever you read at the charger/inverter side connection to the batteries (rear ones in his case) minus whatever the voltage drop is in the center section of cable. This is an issue because if you have a charger that has remote voltage sense, it won't compensate for that loss because it doesn't know it is there because it has to see 12v and is connected to the first battery plus.



I don't know of any way to compensate the charge voltage to take care of this issue as the voltage drop changes with current. If you turn it up at full charge, it will be too high at low currents. IMO, you are better off to just set the charger at the high end of recommended for the batteries and let it be low initially, as you are low anyway in bulk charge. The voltage from the loss will just keep you low a bit longer, but by the time you get to near full on the batteries, they will be seeing almost charger voltage, so your top off charge and monitor calculating full from the amps and volts will be plenty accurate. Of course, using the largest cables you can fit and afford will make the voltage drop lower and improve things a lot.


In the etreks with AGM, the two front battery setup and wiring is one (but not only or worst) issue they have that appears to give them the reduced battery life we hear of fairly regularly. Rewires of them has been discussed here several times in the past with similar changes to what MobileCabin is considering.