Adding 12v DC fridge & solar to 2001 Hawk (replacing ice chest)

[erika]

Hi all,

We are looking to replace our ancient ice chest in our 2001 Hawk, and add solar to run it. We are looking for some feedback on what to get- both the fridge & solar kit (we've already figured out usage calculations). We live in very sunny SW Colorado & camp in high elevations mountains in the summer and Utah desert in the spring. We definitely avoid the heat (above 85). We've looked at these 2 fridges:

1. Engel SB70 DC front opening fridge-freezer for $670.
https://engelcoolers.com/products/70-rv-camping-fridge?variant=33052513763461

Anyone with this Engel SB 70 DC fridge - are you happy with it and how loud is it? We are used to quiet nights and a loud fridge would be a huge bummer. It is self-venting - easier install but bummer for heat retainage?

2. Truckfridge TF 65 fridge with freezer for $699 + $50 shipping:
https://truckfridge.com/products/tf65-12v?variant=32009758212132

We are leaning towards this fridge since we've only seen positive reviews thus far, and they are supposedly Isotherms which FWC uses. The cabinet models are not self-venting and cutting into the camper requires more work. However, after a few of you stated it's not a big deal, we are thinking this may be better so that all the heat is not blown back into the camper.

Anyone know how the 2 brands compare as far as function, quietness of compressor, etc?
Anyone install one of these in a 2001 Hawk and have to vent it?

SOLAR
My neighbors - an electrician & electrical engineer - have helped us with all the calculations. They used this 200W solar kit on their van for $350 & have suggested it for us:
https://www.renogy.com/200-watt-12-volt-solar-starter-kit/

This would be more than we need. We have calculated a 150W would be sufficient for a small fridge & lights. We have 2 deep cycle batteries that will work.

After hearing from several of you, the 200W kit above should be more than sufficient for our needs, even if selecting shady spots.


Thanks for any help!

 

[craig333]

I'm very happy with the noise level of my Truckfridge. As for venting its necessary. I'd really be surprised if the Engel wouldn't benefit from venting also. Its not hard. I watched Marty from All Terrrain campers cut a vent for mine. It was easier than I thought.

 

[CougarCouple]

Hello ericka

We have an Engle MR040 and are happy with our choice. Can be freezer or refrigerator not at same time. Best secure in front of rear axle not behind.

What I would look for in solar.
100ah lithium battery
Dc-dc charger/ solar charger combination with ability to monitor system (depending on vehicle one that can work with new smart alternator)
Placing solar panels in central area of roof is ideal, avoid over front bed area ( measure mounting area before buying)
Do this refrigerator/solar install with the understanding of mounting all mapped out before buying

I’m not an expert but just some point I think are important.
Contact a couple of companies that do solar installs and see what they recommend. There is a recent thread with companies listed.

Russ

 

[ckent323]

I recommend using the Amps per Day Calculation spreadsheet to estimate your electrical usage before buying a house battery and solar system - at the link here:

https://www.wanderthewest.com/forum/topic/828-amps-per-day-spreadsheet/

Once you have a good idea of your electrical consumption needs then you can start designing a system.

Keep in mind that the amount of power available from a Lead acid type battery (FLA/AGM/Gel) is roughly 50% of the rated capacity when discharged routinely (i.e. a 100 Ah battery will provide ~50 Ah of power). Whereas an LiFePO4 battery will provide around 80% of rated capacity when discharged routinely without significantly reducing the battery life.

In addition, a lead acid battery needs to be fully recharged as soon as possible before discharging again in order to maximize battery life. A LiFePO4 battery on the other hand can tolerate a partially charged state.

The point of this is that if your electrical usage in 24 hours is say around 30 Ah - 40 Ah (typical 12v refrigerators consume an average of 2 or 3 amps per hour or 24 to 36 Ah per day) then you need a battery that can cover the overnight usage as well as a solar system that can produce at least as much power that you use a day on average (which varies significantly due to shade, weather and season).

Given weather and shading effects on solar power production many folks add margin to their system size to ensure that in the event they have one or two successive days of low solar production they can avoid shutting off the refrigerator or not have to run the vehicle to recharge the batteries from the alternator.

Considering these things a number of use have upgraded our Solar systems to large residential panels producing more than 300 watts per day due to weight and cost considerations. Panels this size require a controller that can handle upwards of 48 volts and 20 or 30 amps (e.g. Victron 100/20 or 100/30).

Large residential panels are available from residential panel distributors. I bought an LG 360 watt panel for $325 which weighs 40 pounds. I have seen 320 watt panels from other manufaturers as cheap as $235. My new 360 watt panel replaced two 100 watt panels that weighed 21 pounds each and cost $100 each.

If you are using cheap 12V AGM batteries and don't mind replacing them every couple of years due to sulfation caused by cronic undercharging then you may decide to use a smaller and slightly cheaper solar system.

I chose more expensive Lifeline 6V AGM Deep cycle battries that cost just under $300 each. They are now 3 years old and have 3 cycles on them with deepest discharge (2 times) of 50% according to my Victron BVM-700 battery monitor. They are rated for well over 800 cycles.

Vic Harder put together a good post which is worth reading if you have not already:

So, you want to setup a good electrical system in your camper?

https://www.wanderthewest.com/forum/topic/21249-so-you-want-to-setup-a-good-electrical-system-in-your-camper/?hl=%2Bwant+%2Bsolar


I hope this is helpful

Craig

 

[BC3400]

I recently cut upper and lower vents into my FWC and found it fairly easy. Start from the inside by removing the plywood to find the edges of the frames, then use a drill bit to drill a hole into the corners to mark them on the outside. We got the vents from FWC and they installed easily once I had the holes cut out.

 

[erika]

I'm very happy with the noise level of my Truckfridge. As for venting its necessary. I'd really be surprised if the Engel wouldn't benefit from venting also. Its not hard. I watched Marty from All Terrrain campers cut a vent for mine. It was easier than I thought.

Great to know, I have not heard any bad reviews about the Truckfridge, so we are definitely considering this one. Also great to know cutting the vents was easy.

 

[erika]

I recently cut upper and lower vents into my FWC and found it fairly easy. Start from the inside by removing the plywood to find the edges of the frames, then use a drill bit to drill a hole into the corners to mark them on the outside. We got the vents from FWC and they installed easily once I had the holes cut out.

Thanks so much for this info! My husband has a large shop full of tools so he can definitely handle this. Great to know it's not hard.

 

[erika]

I recommend using the Amps per Day Calculation spreadsheet to estimate your electrical usage before buying a house battery and solar system - at the link here:

https://www.wanderthewest.com/forum/topic/828-amps-per-day-spreadsheet/

Once you have a good idea of your electrical consumption needs then you can start designing a system.

Keep in mind that the amount of power available from a Lead acid type battery (FLA/AGM/Gel) is roughly 50% of the rated capacity when discharged routinely (i.e. a 100 Ah battery will provide ~50 Ah of power). Whereas an LiFePO4 battery will provide around 80% of rated capacity when discharged routinely without significantly reducing the battery life.

In addition, a lead acid battery needs to be fully recharged as soon as possible before discharging again in order to maximize battery life. A LiFePO4 battery on the other hand can tolerate a partially charged state.

The point of this is that if your electrical usage in 24 hours is say around 30 Ah - 40 Ah (typical 12v refrigerators consume an average of 2 or 3 amps per hour or 24 to 36 Ah per day) then you need a battery that can cover the overnight usage as well as a solar system that can produce at least as much power that you use a day on average (which varies significantly due to shade, weather and season).

Given weather and shading effects on solar power production many folks add margin to their system size to ensure that in the event they have one or two successive days of low solar production they can avoid shutting off the refrigerator or not have to run the vehicle to recharge the batteries from the alternator.

Considering these things a number of use have upgraded our Solar systems to large residential panels producing more than 300 watts per day due to weight and cost considerations. Panels this size require a controller that can handle upwards of 48 volts and 20 or 30 amps (e.g. Victron 100/20 or 100/30).

Large residential panels are available from residential panel distributors. I bought an LG 360 watt panel for $325 which weighs 40 pounds. I have seen 320 watt panels from other manufaturers as cheap as $235. My new 360 watt panel replaced two 100 watt panels that weighed 21 pounds each and cost $100 each.

If you are using cheap 12V AGM batteries and don't mind replacing them every couple of years due to sulfation caused by cronic undercharging then you may decide to use a smaller and slightly cheaper solar system.

I chose more expensive Lifeline 6V AGM Deep cycle battries that cost just under $300 each. They are now 3 years old and have 3 cycles on them with deepest discharge (2 times) of 50% according to my Victron BVM-700 battery monitor. They are rated for well over 800 cycles.

Vic Harder put together a good post which is worth reading if you have not already:

So, you want to setup a good electrical system in your camper?

https://www.wanderthewest.com/forum/topic/21249-so-you-want-to-setup-a-good-electrical-system-in-your-camper/?hl=%2Bwant+%2Bsolar


I hope this is helpful

Craig

Thanks for all this info, Craig. We have already calculated our usage & should be set with the deep cycle batteries we have. Our neighbors are electricians & electrical engineers and are helping us with this part. The only thing I'm trying to find now is a 150w solar kit that's one panel. We don't need 200w (the kit I linked) and would rather install only what we need. We'd like to upgrade to a new FWC at some point in the very near future.

 

[Beach]

Unless weight or space on the roof is a issue, going from a 150 watt system to the slight overage of a 200 watt system will be a plus when it comes to getting your batteries charged back up quickly. Shading, clouds, rainy days, on roof mounted panels will/can reduce panel output severely and if you enjoy a shaded campsite, you'll probably only get max panel output for a few hours per day. Vic might chime in here as he can provide you with hard numbers on what he sees with his Victron monitored system.

 

[goinoregon]

i would agree with beach's recommendation about solar panel sizing. i like a shaded campsite if available, so i had atc put 2 100 watt panels on my roof. with larger surface area, i figure i might catch more rays .

 

[erika]

Great points, Beach & Goinoregon. We rarely have cloudy days or rain for more than a day (if we are lucky) but we definitely seek out shady campsites whenever we can.

 

[Jon R]

Adding 35% extra panel capacity over what is adequate in sunny conditions will not come close to making up for the loss of output in shade or overcast conditions. My 400 watts of panels put out about 60 watts midday in overcast conditions. Less in shade. I’m not saying 200 watts is a bad sizing choice, but it won’t put out much more than 30 to 50 watts on overcast days.

 

[Vic Harder]

320w single panel on our Puma is plenty most days. Last August in Northern BC it couldn’t keep up. Having dcdc charging as an option provides a lot of flexibility and confidence.

Biggest thing is to have a good shunt based monitor so you can observe and adjust your usage

 

[BlueSky]

I guess I might be the odd man out here since I have just one 110w flexible panel (Sunpower) on the roof, Victron solar charger, and a Lifepo4 100ah battery, and I live in CO and have no problem keeping my Dometic 50 qt fridge going. I use the lights, furnace on cold mornings, fantastic fan on hot afternoons, water pump, and I charge my phone too. I am simply not running out of power. I was going to add a DC-DC charger but decided against it. Instead I have the old wire running from the bed plug-in wired to the truck's battery, and if anything ever happened to my Lifepo4 battery I would just connect the truck's battery and reprogram the Victron controller for Lead Acid. Just keeping it light simple works for me.

 

[erika]

I guess I might be the odd man out here since I have just one 110w flexible panel (Sunpower) on the roof, Victron solar charger, and a Lifepo4 100ah battery, and I live in CO and have no problem keeping my Dometic 50 qt fridge going. I use the lights, furnace on cold mornings, fantastic fan on hot afternoons, water pump, and I charge my phone too. I am simply not running out of power. I was going to add a DC-DC charger but decided against it. Instead I have the old wire running from the bed plug-in wired to the truck's battery, and if anything ever happened to my Lifepo4 battery I would just connect the truck's battery and reprogram the Victron controller for Lead Acid. Just keeping it light simple works for me.

Bluesky, this is all helpful info and especially great to know 110w has been enough for you in CO. We have another friend with a newer FWC Hawk in CO that has been fine with a 100w panel too. We camp in remote, high elevations in the summer and if there are any trees/shading, we still get many hours of sun. We'd also keep the same setup with our wired-in battery charger (to truck) and were wondering how that worked as a backup.

 

[BlueSky]

Bluesky, this is all helpful info and especially great to know 110w has been enough for you in CO. We have another friend with a newer FWC Hawk in CO that has been fine with a 100w panel too. We camp in remote, high elevations in the summer and if there are any trees/shading, we still get many hours of sun. We'd also keep the same setup with our wired-in battery charger (to truck) and were wondering how that worked as a backup.

I have not tried the truck battery backup yet. I have a fuse that I can put in when I want the truck battery as main power supply in place of the LifePo4. I'll wait until I really need it out in the boonies before trying it out

 

[oldhotrod]

I guess I might be the odd man out here since I have just one 110w flexible panel (Sunpower) on the roof, Victron solar charger, and a Lifepo4 100ah battery, and I live in CO and have no problem keeping my Dometic 50 qt fridge going. I use the lights, furnace on cold mornings, fantastic fan on hot afternoons, water pump, and I charge my phone too. I am simply not running out of power. I was going to add a DC-DC charger but decided against it. Instead I have the old wire running from the bed plug-in wired to the truck's battery, and if anything ever happened to my Lifepo4 battery I would just connect the truck's battery and reprogram the Victron controller for Lead Acid. Just keeping it light simple works for me.

No, I am in a similar boat. I use a 160wt flex panel and 50ahr battleborn. The simple system has kept up with my 50L endelb cooler, fantastic fan and lights no problem although it would be the minimum in my opinion.

 

[BlueSky]

I figure there are 3 main things that can break in the solar charged battery system, the LifePo4 battery, the solar controller, or the solar panel. If the solar panel or charge controller dies, then I have to manage the amp hours I have left in the LifePo4 battery until I can plug into shore power somewhere. Not the end of the world, but after a couple of days I probably have to head home and order stuff. I suppose a DC-DC charger would be handy in this situation. If the LifePo4 battery dies, then I can put the fuse in to connect everything to the truck's battery and change the battery setting on the Victron controller for lead acid. If I put that fuse in and it blows right away, then I am kinda screwed unless I can figure out what is going on. I suppose if I were to head out for a few weeks, say to Baja, then I would add a DC-DC charger and a second solar panel on the roof because that thing is exposed up there and it could get damaged. I could also add a switch that isolates the LifePo4 battery from the system. Don't mind me, I was an aerospace engineer

 

[craig333]

The way I see it is I'll get a bulk charge without a DC-DC charger and thats all I need until the solar can take over again. Unlikely I'd need shore power especially since I have an abundance of amp hours to start with. I even have my old controller still in place, just need to swap the wires if the controller failed. Nice thing about having two panels, I'll still get some charge even if one fails.

 

[erika]

Thank you for all this info everyone! I'm still getting my head around how it all works.