19 replies to this topic

[Jollyrogers]

I had a long post. Lost it. Still a long post.

2nd set of AGMs are on last leg in 2015 Hawk. Dometic AC/DC 65. Dual fans and LED lights.
I camp by myself. No fridge typically and use a cooler. I could leave the house and probably camp a week.

With wife fridge and power requirements are maxed for my Hawk. I used to get a couple days without charging. Now I can’t make it through the night even after a full charge. Time to replace, but noticed I can get a Lifepo BMS 100ah fairly reasonable now. Not worried about charging in low temps either.

We tend to charge and cool fridge night before using shore power. Camping we use a 200w suitcase (lithium compatible) or a honda 1000 (we camp under trees a lot in the NF) to keep batt(s) charged. Either do the job.

I’d like to just disconnect from truck. The truck to house charge just sucks. Probably because of the smart alternator and poor wiring to house batts.

So I THINK what i want to do is:
-1x100ah BMS LifePo
-Progressive Dynamics PD9145ALV for shore power so I can top off before traveling or charge from genset. It has the IOTA DLS-30/IQ4 and have read mixed info about charging lifepo batts with it.
-Battery monitoring
-Add 100w roof solar to charge while driving. And use 200w suitcase and honda 1000 once at camp spots. Either will do the job after a few hours. Most trips are within 4 hours travel time.

Later maybe add a DC-DC and improved wiring for truck (2019 RAM 2500) to House batts.

Is this a sane way forward? Do I have to replace the IOTA? Could 100w roof keep me going ok long enough while traveling for the day? Or should I go improved wiring and DC-DC now, and replace the IOTA later? How hard is it to replace anyways (I am pretty sure I can do it as I’ve been a radar tech for 30 years)?

I’ve read a lot and it’s all overwhelming but got me to at least this point. It’s also an investment of money I really don’t want to spend… lol, but seem I need to at some point.

I have a solo trip for a week in Aug planned. At a minimum I could just get the battery and keep it charged with my suitcase since I won’t be using any real power. But by this fall the wife will be wanting to hit the appalachian mountains.

Edited by Jollyrogers, 05 July 2023 - 04:41 PM.

[Cpt Davenport]

I added a 206 ah SOK lithium to replace the lead acid factory battery on my 2022 Hawk. I have 175w panel on the roof with an aux 130w foldable panel. I can go 5 days with little to no sun running the fridge, two fans, lights and charging my electronics. The only change I made to the factory install was disconnecting the camper from the alternator. I will eventually instal a DC/DC charger with larger wire from truck to camper, but have not needed to do that yet. Beauty of the lithium is I can run it down to 50% or less with no worries. I'm able to also charge the battery from shore power with no modifications but not to 100%. No worries though as the solar tops it off just fine.

[Jollyrogers]

@Cpt Davenport what AC-DC converter/PS does your year have?

I’ve read the IOTA w/IQ4 may send 14.8v and will only get the Lifepo to 60%, which would suck if using my generator. The BMS may protect if the voltage is slightly high?

It does sound like I could get away with it though, and use solar to top off, and forego a truck connection.

[Vic Harder]

Lots to think about.  Starting with the rooftop solar.  100W is very small, but using that for 4 hours would give you a maximum of 28AH of charging (100W/14V=7A is your charging current, times 4 hours = 28AH... but you will never see that given about 20% in various losses).

 

Is that enough for you?  

 

In contrast, charging from the Alternator could get you 30A or more, so 120AH of charge in 4 hours.

 

Vic

[Jollyrogers]

Thanks Vic. It may make sense to wire the truck and go DC-DC, especially for ROI. I just don’t like it I know my 200 suitcase charges and keeps up with my fridge in good sun draw, I see 10-15amps during bulk rate charge. So your point is valid for the 100w panel.

I know I have to do something for during travel, and have never been fond of the connection to the truck.

[Cpt Davenport]

@Cpt Davenport what AC-DC converter/PS does your year have?

I’ve read the IOTA w/IQ4 may send 14.8v and will only get the Lifepo to 60%, which would suck if using my generator. The BMS may protect if the voltage is slightly high?

It does sound like I could get away with it though, and use solar to top off, and forego a truck connection.

I'm uncertain of what converter is in my unit. I seem to remember getting my lithium charged to the upper 80's% when plugged in though. I will take note next time and report. If you have the time and money I would do the DC/DC charging and wire upgrade. I have not run out of juice yet but came close. Charging from the truck would provide peace of mind for the close calls on rainy days. 

[Jollyrogers]

Thanks! I have a generator for emergency. But Yea, I am looking at going DC-DC now and pricing things out instead of roof solar.

I need to go read through the threads I guess to see what is best.

[Cpt Davenport]

I would not skip the roof solar. It is a small investment for free power. My 175w flexible panel was around $250 and weighs under 7 pounds installed. I just finished a 3k mile trip and only had quite a few cloudy/rainy days. My battery never fell below 60% with no other means of charging. The combination of solar and charging from the alternator is the optimum set up. This way you can leave the generator behind.

[TacomaAustin]

It is important to know your own consumption rate in watt hours per day.  My consumption rate on a hot August day with a 12 volt fridge and excessive use of the vent fan can exceed 500 watt hours over 24 hours.

 

To add to what Vic said, definitely go larger than than the planned 100 watts on the roof solar panel.  My main reason is the roof solar panel lays flat. So, with blue skies and good sun on a summer day, a 175 watt panel may only provide a 150 watt charging rate, which I'll guestimate to be little more than 10 amps per hour.

[Jollyrogers]

I’m probably right there with you Austin, on daily usage when camping with the wife.

I talked it over with her and she suggested “I do it right”.

So with that:
1. Lifepo 100 amp probably add a second within a month or 2 if I like the setup.
2. Victron smart Dc-Dc 30a isolated
3. 6ga from truck to charger. breaker at each end.
4. Anderson connector in bed
5. Victron shunt smart batt monitor.
6. Progressive International PD9130LV AC/DC for shore power.

I will charge from truck during travel, and my 200w suitcase or 1000w genset as needed when stationary.

I’ve read the DC-DC can run hot. Where is best place to mount in a side dinette HAWK?

Is the PD9130LV a drop in replacement for the IOTA/IQ4?

I guess I can figure out how to bring wiring in. Not sure what to do about camper lights yet…. which have to work for VA safety.