Espar Battery Setup

[djb5118]

Hey all -

Decided this might be the best spot to get some advice. I'm currently building out an Espar D2 setup for my truck bed camper, and wanted to find a way to have the 12v power be something I rarely have to think about. At most, I would be running the heater for 8hr (or so) roughly 2x/weekend. Based on my research the heater will draw 2.8 amps in "boost" mode, so absolute worst case would be roughly 23ah per night or 45ah per weekend. That would mean I'd want at least a 100ah battery.

My questions:
-Does that battery assumption make sense?
-How large of a panel would be needed to keep this puppy charged up?
-Are there any reliable go-to sites to buy these type of systems that tells you everything you need to install? (i.e. how Crutchfield is for car audio)

Noob questions I realize, but still learning. I'm open to any thread suggestions also if there are specific topics around this already.

 

[plh]

Hey all -

Decided this might be the best spot to get some advice. I'm currently building out an Espar D2 setup for my truck bed camper, and wanted to find a way to have the 12v power be something I rarely have to think about. At most, I would be running the heater for 8hr (or so) roughly 2x/weekend. Based on my research the heater will draw 2.8 amps in "boost" mode, so absolute worst case would be roughly 23ah per night or 45ah per weekend. That would mean I'd want at least a 100ah battery.

My questions:
-Does that battery assumption make sense?
-How large of a panel would be needed to keep this puppy charged up?
-Are there any reliable go-to sites to buy these type of systems that tells you everything you need to install? (i.e. how Crutchfield is for car audio)

Noob questions I realize, but still learning. I'm open to any thread suggestions also if there are specific topics around this already.

You kinda answered your own question. You will need to dump 23ah per day back in to keep your battery 100% charged. The items missing are expected sun hours, and if you plan to be 100% off the grid every day or will you "recharge" during the week for weekend camping... Weekend warrior you will be good with a 100W panel. Just be sure you are getting sun during the week to keep it topped off.

 

[djb5118]

Remember to add up Espars ignition current.
I sort of remember my 12v D1 & X2 heaters draw about 12 amps for ignition what lasts about a minute. I expect Espar has ignition 'specs for your D2 published.

If its controlled on a thermostat, depending how many ignitions per night can add up...
Conversely, during its off time, it draws nothing. Total consumption average might be a wash.
Who knows ? Fire it up & take measurements...

Good point - I was able to find that the ignition draw is 8.3amps, so slightly less than your D1.

You kinda answered your own question. You will need to dump 23ah per day back in to keep your battery 100% charged. The items missing are expected sun hours, and if you plan to be 100% off the grid every day or will you "recharge" during the week for weekend camping... Weekend warrior you will be good with a 100W panel. Just be sure you are getting sun during the week to keep it topped off.

Ya - my use is primarily in the mountains in the PNW, so sun time is very day-by-day. I would be able to charge the battery during the week while parked at work or even plug in at the house. Of course, it's not always sunny when I'm at work either ha.

 

[secondseason]

So I have wondered the same thougths

I wondered the same thoughts when I put the heater in my van. What I have learned with 1 year of use has amazed me.
1- I think the 2.3 amps is at max heat which I have yet to use other than the how hot can I get it question.
2- When I leave it on the lowest setting and leave it on the power usage appears to be very low. I mean really low.

I have 2 100 watt solar panels on the roof and can charge while driving 2 100 amp batteries hanging under the van. I run a fridge full time/37 degrees and the heater on the lowest setting all weekend and never got below 12.5 volts on the bank.

The heat is worth any draw living up in the PNW helps dry out gear and warm up after skiing, hunting or mt. biking

good luck

 

[jonyjoe101]

in winter you get less amps out of your panels. My 240 watt panel connected to an ecoworthy 20 amp mppt gets me about 9 amps in winter about 12 amps in the summer. Thats with full sunshine. In cloudy conditions you might get 5 amps. Barely replacing what you used the night before.

With a 100 watt panel you might max out at 5 amps, maybe 2 amps in cloudy weather. That will never charge up your battery.

I always recommend get the biggest panel that you can fit on your roof, they squeeze every last ounce of power from whatever sun is available. Even when its raining I can get 2 amps out of my panel, where a smaller panel will give you nothing.

Panel is simple to install. You have to drill 4 holes, make sure you use rv putty tape so you wont get any leaks.
The wires can be run through any vents/etc you got on the roof. The "L" brackets to mount the panel you can buy at home depot for about 6 dollars.

For a smaller low voltage (less than 30 volts) panel all you need is a 10 amp wincong pwm controller (about 20 dollars), this will also work on the larger panels but wont get the higher amps it can produce out of it.

For larger high voltage (over 30 volts) panel , you need an mppt controller if you want to get maximun amps. ecoworthy 20 amp mppt (cost 100 dollars) will work, and you can also use it on smaller panels but wont extract any extra amps out of them.

The controllers all install the same 2 wires to panel, 2 wires to battery. You can leave them connected all the time, the controllers will never produce enough voltage to damage the batteries.

 

[djb5118]

What if I were to just skip the solar panel and charge the battery in the house regularly? I would imagine that wouldn't be the worst plan if I am only using this a few days a week?

 

[Bbasso]

Seems like solar would be your best best and I'd usually agree, but you should consider a blueseas ACR to charge your battery. Just be sure to drive it regularly or keep it topped off with the charger at your house.

 

[hour]

I would get a 105ah group 31 deep cycle - batteriesplus has this by Duracell on sale for $90 after coupon. Stash that under your sleeping platform. Get a cheap $5 fuse block (or a fancy blue sea one) and run 8 gauge to it. A cheap amp wiring kit would cost less than buying a spool of 8 gauge and a package of ring terminals, and I wouldn't sweat copper clad aluminum for this.

Now you could wire up LED lights in the shell and even give yourself a cigarette lighter and usb ports. They sell panels that have dual usb, voltmeter, and cig lighter all in one for ~$15 on Amazon.

I ran solar on my old trucks camper shell and never had the heart to drill for the wiring. Even uncooperative MC4 solar extension cables could still fit through the crack left from the shell's rear window meeting the tail gate. If you make your own solar cables, which I've started doing using low voltage landscape wiring, you could easily fit it through a crack in your shell and it wouldn't be a hassle given the flexibility of that wire

I'd do the above battery setup, a $10 10amp solar charge controller, and a flexible 100w panel. Adding a roof rack to your shell would give you a good place to secure the panel, but you could opt to just lay it on top and bungee through two of the grommets on opposing corners and down to your shells side windows or where the shell meets the truck bed. Tuck the wire through a crack in your shell glass and you're golden.

Total investment would be like $250 all from Amazon with prime shipping :victory: You could either leave mid day and hope that your battery was somewhat replenished by that time, or put the panel on the roof for one afternoon when you're in town. I wouldn't mess around with having to haul the battery inside to charge, weekend warrior or not.

 

[djb5118]

Is AGM worth the premium?

Luckily I have the roof rack already, so it could be a good mounting option, but temporary could work if I don't want to have the wire hanging out all the time.

 

[DaveInDenver]

Is AGM worth it? Maybe, depends. They are easier to install as orientation is not critical. They are completely maintenance free and don't vent normally if you happen to have a small enclosed space. But that is a double edged sword since you also can't add electrolyte if you overheat and cause it to boil.

In a vehicle I think sealed is better but in a more forgiving environment (temperature, vibration, etc) or a situation where a good box can be constructed the argument against wet cells isn't as strong IMO. You get more battery for your money with wet cells and being able to measure specific gravity and inspect the plates is useful.

 

[hour]

My thought is that you won't be in the truck bed sleeping when it's charging significantly, unless you're sleeping til noon. And even then... PNW. Snow. Overcast. If your sleeping platform is really low or you do some crude measurements and determine that a battery of your liking would fit better laying down, AGM. Otherwise I wouldn't waste the coin.

 

[jaho]

I have a truck and truck camper. My Espar is a coolant heater which I will be using as "block heat" in the winter when I can't plug in, but the coolant will be plumbed into my truck camper as a heater as well, I will be heating the camper with it during winter nights, but want to keep the functionality of the coolant heater even if the camper isn't on.

My question is, which battery do I connect to? I am hesitant to connect to my starter battery during camping because I will be running the Espar a lot, and the camper has 250 amp hour battery, so its logical to connect to the camper battery. But, if I take the truck camper off, I still want to be able to use the Espar, which would mean I would need to disconnect from camper power and connect to starter batteries?

The camper stays on most of the time, so moving the power source from one to the other wouldn't be a huge deal, but looking for a little guidance.

Thanks

 

[dreadlocks]

House Battery Obviously, how often are you really gonna take camper off if its tied into engine cooling loop.. If you take it off, and plug that up.. then setup like andersons or something so you can plug it into the starter battery.

or another battery just for the heater thats joined to house batteries with camper, and becomes its own house battery with camper removed.. a block heater has a circulation pump to run too so thats going to take a bit more power.. my Webasto OEM block heater has option to set custom low voltage disconnect, think by default its at 11.7v.. mebe your Espar has similar functionality, that would make it much easier to integrate w/starter battery so you know it'll shut down before it drains battery to point you cant start it.