Tiniest Hymer Promaster Carrado/Axion

[GeorgeRa]

Originally Posted by EdSoCal1

I've read all 30+ pages of posts, but being a newbie, I hope someone doesn't mind clarifying. I'm looking at solo RVing for a bit, tho my son, gf and toddler might use it once in awhile, but since they've done tent camping, maybe they could make this work for them. The Travato seems a fit too, but I don't need the extra length if I just end up with a wetbath anyway. And the Sprinter based RVs sound like a typical Mercedes high expense maintenance, otherwise, the Winnie Era 70M with drybath and slideout looks awesome. Feel free to shoot holes in my logic, you all know much more than me on this.

1) A/C Generator: Running the A/C off a generator is fine by me. On the Axion, would that be the underhood generator powered by the RV engine? And can it also power the Microwave oven, but probably not both A/C and Microwave?

2) Propane: Alde furnace/water heater and Stove

3) The standard AGM batteries power which items? Refrigerator via DC voltage? No alternative power source (no propane) for refrigerator? TV?

4) Does having solar really do much for the AGM batteries that running the underhood generator for half hour wouldn't do?

Thanks

Starting a new thread could be a good idea.

[EdSoCal1]

I meant above questions to be about the Axion only. I didn't make that clear, sorry.

[gregmchugh]

Originally Posted by EdSoCal1

4) Does having solar really do much for the AGM batteries that running the underhood generator for half hour wouldn't do?

One of the things you need to do to get a long life from your AGM batteries is to get them to a full charge on a regular basis. AGM batteries have two stages of charging followed by a float charge voltage when they are at full charge.

The first phase of charging is the bulk phase where the batteries can take high charge currents up to the point where they are 80-90% full. This phase of charging is a good time to use the underhood generator since it can provide high charge current.

The second phase of charging is the absorption phase where it takes several hours of charging at lower charge currents to bring the batteries to full charge. This phase of charging is a good time to use the solar since it can provide lower charge current over an extended period of time. This is not a good time to use the underhood generator since you don’t want to be running the engine for hours at a time to provide a low level charge current. If you are driving anyway then there is no need to worry about it but if you are camping in place then running the engine for hours is not desirable.

A good strategy if you are camping and not driving is to run the underhood generator in the morning to do the bulk charging and let the solar handle the absorption charge the rest of the day. If you have a need for high load devices during the day then this strategy may not work out but unless you are using the air conditioner from the inverter you will typically not use a lot of power during the day.

[EdSoCal1]

Thanks, Greg for the thorough response on the solar charging and how important it is to top up the AGMs. You also made me think, if the RV is parked at home for a long time, the solar would be great in keeping the AGM batteries topped up.

[avanti]

But, you don't really have to top them up EVERY cycle, right?

[gregmchugh]

Originally Posted by avanti

But, you don't really have to top them up EVERY cycle, right?

No, but I don’t remember any specific rules for how often they should get to full. It always seems to be often or regularly or some other wishy washy instruction...

[gregmchugh]

Originally Posted by EdSoCal1

Thanks, Greg for the thorough response on the solar charging and how important it is to top up the AGMs. You also made me think, if the RV is parked at home for a long time, the solar would be great in keeping the AGM batteries topped up.

When parked for a long time you have several options.

1. Use solar or shore power to keep them fully charged.

2. Have them disconnected from the loads and just let them sit. AGM batteries have a very low self discharge rate. Every once in awhile charge them back up to full. I will let someone else propose a guideline on how often based on the self discharge rate which I don’t recall at the moment.

[gregmchugh]

Originally Posted by EdSoCal1

Thanks, Greg for the thorough response on the solar charging and how important it is to top up the AGMs. You also made me think, if the RV is parked at home for a long time, the solar would be great in keeping the AGM batteries topped up.

I should add that in order to keep the chassis battery charged when parked for a long time you can use the solar or shore power option along with a Trik L Start or some other device connecting the chassis battery to the AGM battery.

I don’t think there is a battery separator any more on vans with the underhood generator.

[mumkin]

Originally Posted by EdSoCal1

Thanks, Greg for the thorough response on the solar charging and how important it is to top up the AGMs. You also made me think, if the RV is parked at home for a long time, the solar would be great in keeping the AGM batteries topped up.

The solar is fabulous for keeping your AGM(s) topped up if it is parked some of the time. No more running out every few days to make sure that the battery is OK. I love my solar and would never be without it again.

The fridge can be set to 12v only - which Roadtrek told me to do. It is the same fridge as the Axion. The solar can keep it going for a few days if little else is tapping it. No more propane fridge (hooray... level doesn't matter).

For your starting battery, most recommend one of those solar trickle chargers that you can plug down by the steering column.

The underhood generator is just a second larger alternator. I wouldn't even try to run the AC and microwave at the same time. And I wouldn't plan to be running the AC all night. I would think more in terms of a couple hours to cool down the rig until the sun goes down and you can open all the windows and use the fantastic fan. Oh wait... you only have a little bathroom fan... But it shouldn't be hard to cool a van that small.

[silex840]

To those of you asking to use an app with your solar charge controller instead of the MT50 remote display, one of these wireless add-on boxes will do the trick. Much more convenient than the wired option. There is both an Android and iOS app as well.

EPever eBOX WIFI 01 RS485 to Wifi Adapter for MPPT Solar charge Controller Communication Wireless Monitoring by mobile phone APP (eBox-WIFI-01) https://www.amazon.com/dp/B07CJLVZ13..._fRQhBb52W9B98

EPever eBOX BLE 01 RS485 to Bluetooth Adapter for MPPT Solar charge Controller Communication Wireless Monitoring by mobile phone APP (eBox-BLE-01) https://www.amazon.com/dp/B078Y3W9Y3..._mZQhBbYWTYN62

Bluetooth being the preferred option since won’t need to disconnect from WiFi every time to check on stats on a separate local network.

[wincrasher]

Originally Posted by silex840

To those of you asking to use an app with your solar charge controller instead of the MT50 remote display, one of these wireless add-on boxes will do the trick. Much more convenient than the wired option. There is both an Android and iOS app as well.

EPever eBOX WIFI 01 RS485 to Wifi Adapter for MPPT Solar charge Controller Communication Wireless Monitoring by mobile phone APP (eBox-WIFI-01) https://www.amazon.com/dp/B07CJLVZ13..._fRQhBb52W9B98

EPever eBOX BLE 01 RS485 to Bluetooth Adapter for MPPT Solar charge Controller Communication Wireless Monitoring by mobile phone APP (eBox-BLE-01) https://www.amazon.com/dp/B078Y3W9Y3..._mZQhBbYWTYN62

Bluetooth being the preferred option since won’t need to disconnect from WiFi every time to check on stats on a separate local network.

That is the route I went with my Victron solar controller. Their bluetooth dongle and phone app not only gives detailed output information, but does data logging so you can see what it's done over time. I have months of data in the log, not sure what the upper limit is on it.

[silex840]

Hey guys so random thought. My other vehicle besides the Axion is a Nissan Leaf all electric car with a 24kWh lithium battery pack. Is there a way to wire the 12v@100A car battery off the Leaf to one of the lithium power switches in order to power the coach? Would this require reprogramming the built-in 2000W pure sine wave interver?

Or does it make more sense to use a 1500W inverter (pure sine wave even necessary?) off the car battery to get the 120VAC@15A with the shore power cord connected? This would be done while stationary of course. The ultimate goal would be to charge up the coach battery while still being able to draw power as needed which I wasn’t sure if it was possible with the first suggestion with a direct connection.

[kmrotterdam]

I enjoyed reading all the comments for this thread on the Axion. I've learned a lot and I have signed a purchase contract for the Axion with all the options. I will be picking it up in a little over one week. Someone mentioned on here that there were no Facebook pages for the Axion, unlike Facebook pages for almost all the other big name models, so I created one if anyone is interested: https://m.facebook.com/groups/215749...content_filter

I am so looking forward to my new van, I've had an American Cruiser for a while and loved it, but I wanted something new to take me into the future for the next 20 years.

[falfal3]

Congrats!!! Thanks for the FB page, I'll be joining that one fo sho. One tip, I went out and found I had drained my batts down to 4.68 vdc. nothing in coach would power up. I tried hooking to 30 amp svc for 24 hrs and driving for an hr, NO GO! Talked with cust svc, Nevin, who had me hook batt charger directly to inverter (pos and neg). Charged up to 12 vdc, then generator would work. I'll now make sure to have each bank charged (ecotrek 400) but only use 1 unless I'm hooked to shore power.

[booster]

Originally Posted by falfal3

Congrats!!! Thanks for the FB page, I'll be joining that one fo sho. One tip, I went out and found I had drained my batts down to 4.68 vdc. nothing in coach would power up. I tried hooking to 30 amp svc for 24 hrs and driving for an hr, NO GO! Talked with cust svc, Nevin, who had me hook batt charger directly to inverter (pos and neg). Charged up to 12 vdc, then generator would work. I'll now make sure to have each bank charged (ecotrek 400) but only use 1 unless I'm hooked to shore power.

The Roadtrek BMS system should not allow that to happen. The owners should not have to go through hoops to keep from having dead, allegedly hi tech, batteries.

[falfal3]

Originally Posted by booster

The Roadtrek BMS system should not allow that to happen. The owners should not have to go through hoops to keep from having dead, allegedly hi tech, batteries.

I agree, BUUUUUUT, that's my reality. I'm fine, now I know, with always leaving 1 bank fully charged and off. I feel bad for those that only have an Ecotrek 200.

LOVIN' my little Axion.

[kmrotterdam]

Do the EcoTreks have to be ON to charge when connected to shore power or while driving?

[falfal3]

Originally Posted by kmrotterdam

Do the EocTreks have to be ON to charge when connected tn shore power or while driving?

yes for both but with shore power, inverter must also be on. Inverter doesn't need to be on when driving, at least that's what "How To" for Ecotrek says.

[kmrotterdam]

Goodness, I have to remember all of this!
Inverter & EcoTreks on when on shore power, but inverter off when driving, but EcoTreks remain on. And don't forget to turn EcoTreks off when you've arrived at your destination!

[BBQ]

.

For shore power,
you MUST turn on the inverter BEFORE plugging the cable in the socket.

I know this is crazy... so many little things to remember.