[uNik]

This week for 2 evenings I made some aluminum welding.

Since I do not have ~220v shore-power in my work-place I didused vans batteries and ~220v power inventor.

My ProMaster has 3 deep-cycle 105A marine auxiliarybattery’s, with original vans I do have 4 batteries on BOARD all connected inparallel.



After about 2 h of a weld job, have to mention TheWelding-Arc time was aprox ~15min.

I discharged all 4 batteries to 12.5volts (measured on eachbattery separate).

I do not have solar-panels yet. The way to charge batteriesis to DRIVE a van.

I decided just to IDLE vans motor for about 20 min.



To my SURPRISE after 20 minutes of idling vans motor avoltmeter show’s 13.8V on every battery.



FOLKS; have to mention = After I installed my POWERAux-system I constantly monitoring alternators upcoming VOLTAGE. When motor isrunning, alternator makes 14.1 ~14.2 volts. (does NOT matter driving or idling)



So, my BOTTOM Line = by Watt’s law I have

220Amps (vansalternator rating) x 14volts = 3,080 Watts of power !!!!



This numbers is WAY HIGH 3080W

if any of Solar’s panels I may accommodate on my ROOF

 

[uNik]

My Question to FOLKS with Solar-Panels; How long it takes approximately to charge BATTERYs from 12.5v to 13.8v ???

 

[jostalli]

How is your house battery connected to your alternator and where are you monitoring your alternator's voltage?

 

[papab]

I think your post is a bit confusing, your batteries are not charged up to 13.8 V, It sounds like they were charging at 13.8 V with the van running. What voltage do you read when you haven't charged for several hours and the loads are off? That will be a better measure of how much they are charged up.
http://batteryuniversity.com/learn/article/how_to_measure_state_of_charge

You don't need to size the solar from the size of the alternator, you need to size it based on your daily load.
Try one of these:
http://www.rvsolarelectric.com/index.php?route=directory/directory&directory_id=3
http://www.amsolar.com/home/amr/page_26

 

[uNik]

How is your house battery connected to your alternator and where are you monitoring your alternator's voltage?

Every battery is connected by marine-boat switch 1,500amps MAX rating for 1 min, continuos load 400amps.
So I do have total 4 switches and 4 batteries.
This way I can connect all 4 or any combination of batteries I need.
Sure for WELDINING MAX power needed.

From a van's battery I run 2 gages wire to a 1rst switch.
All 4 switches accommodated to 2x2inch aluminum channel.
Alumunum channel works like an electrical bass, which is connected to 5,000watts inventor. Rest of a switches (N* 2,3,4) brakes connection from bass to 3 auxiliary's batteries.

WILL post pictures later and schematics.

MONITORING VOLTAGE, (as I posted on beginning)
1) Motor running ALL 4 batteries in parallel Voltmeter = 14.1 volts
2) Motor NOT Running ALL 4 batteries separated (disconnected) from eatch other. VOLTAGE reading on every battery measured separately 13.7 to 13.8 volts.
I did measuments "Right after" I stopped motor running.
Will take advise and measure voltage after some time (1 hour, 1 day, 2 days)
I stopped motor

 

[uNik]

I think your post is a bit confusing, your batteries are not charged up to 13.8 V, It sounds like they were charging at 13.8 V with the van running. What voltage do you read when you haven't charged for several hours and the loads are off? That will be a better measure of how much they are charged up.
http://batteryuniversity.com/learn/article/how_to_measure_state_of_charge

You don't need to size the solar from the size of the alternator, you need to size it based on your daily load.
Try one of these:
http://www.rvsolarelectric.com/index.php?route=directory/directory&directory_id=3
http://www.amsolar.com/home/amr/page_26

Thank you very much for direction to wwwww.
I will really apriciate if you post voltage reading from your van's batteries in two cases.
1) MOTOR Running =Voltage ?
2) MOTOR NOT Running =Voltage ?

P.S. Yes, this above (voltage) really CONFUSE me, there for I post it to Forum

 

[papab]

Thank you very much for direction to wwwww.
I will really apriciate if you post voltage reading from your van's batteries in two cases.
1) MOTOR Running =Voltage ?
2) MOTOR NOT Running =Voltage ?

P.S. Yes, this above (voltage) really CONFUSE me, there for I post it to Forum

1)motor running, 14.1 - 14.3
2) motor not running, house battery is 12.8 when fully charged, after 8+ hr rest, no loads.

 

[uNik]

Posting pix
1.* Switches panel lays up on support board to position 5,000wats invertor a better position.
Job (1) was needed after install air-fan into fuel-tank cover-hatch. I did removed hatch and on existing opening mount aluminum-house (carpeted with blue-carpet) and computer +12v 120mm cooling fan.
THIS Vent with 120mm PC cooling fan I did used on my Sprinter van for 8 years (have to DRILL a hole in a Sprinter van)


2.** Switches panel from a back-side. For a main connect-contact I use aluminum plate 4mm thick.
On a pix you see 3 switches connected to 3 AUX batteries. The 1 switch on a right side is not connected (on a picture) and it designated to be connected to a main-van battery.


3.*** In a center of a pix you see PC cooling fan mounted in a house-box. Also wires from AUX 3 batteries box. In order to get every battery supported with 2=gages wire, I did used "skiny" wires 4 gages and 6 gages running in parallel So do Math :nerd: 6:3=2 or 4:2=2 :|


4.**** Main view. To protect switches I have plastic-glass 1/2" thick cover over contacts, in this picture plastic-glass cove standing on a back of driver's-seat


5.*****Back side of 5,000w power invertor. On a connecting lags "L" channel to what I screw aluminum "bass" terminal with 4 switches

 

[uNik]

After 12 hours measure voltage on each battery (was fully charged to 13.7v)
1* vans original battery =12.6v
2* aux =12.8v
3* aux=12.8v
4* aux=12.8v

It is kinda of ENIGMA to me ; where 1 volt went in 12h of batteries just sitting over-night without taking power from.

Other STAFF what I found in my alternator-charge batteries = if in 20 to 30 min I can fully recharge my batteries, WHY I NEED Solar-panels ???

Folks I am not denaing Solar-Power, but if I am driving every day, my alternator gives me power ANYWAY

 

[seapro]

12.8 is fully charged. Just after charging a battery will show higher because of "surface charge" which will drop usually within 24 hours. This happens without any load. That is why manufacturers usually recommend letting a battery "rest" before checking. Remember 12.8 is full up.

The van battery goes down because of continual loads due to computers, radio memory, and many other things. I observe the same thing. Also an open door causes a load for inside light(s). I have a Bluesea ACR charge relay connecting the two systems and I have a shore power connection. The charge relay works both ways. When I leave the van parked for over two weeks without being driven I plug it in at my storage garage and recharge the van battery from the house system.

I agree about solar and I have none. For me it is a waste as I do most camping in the north and often in the winter with low sun angles. Also I often camp in the shade under trees. My single 230 amp hour size 8D house battery is good for 2 or 3 days without recharge. Then a couple of hours driving fills it back up.

 

[MsNomer]

Finally. Someone who agrees with my reasoning re solar. I'm a true believer in the technology and for many/most people the van is a perfect application, but for much the same reasons you list, plus the debris that gathers on the roof when parked in our driveway under trees, just doesn't seem like it would work for us.

We have only 100 AmpHr house battery, but in three days sitting in the driveway in temperatures ranging from about 40° to 75° (the kind of temps we seek to hike in), fridge empty but running at 38° (worse case than full), we have used seven --that's s-e-v-e-n AmpHrs according to the TriMetric meter. LEDs and charging don't add much to that.

 

[johnnybesurfing]

After reading all the posts on this subject and calculating my needs, I agree with MsNomer, RD and Unik. No need for solar. Most of my energy will be for heating water for my shower (by the way will be used every day after a surf) and heating the back of the van with a olympian 3 radiant heater all with propane. I plan on putting a second agm battery under my seat as outlined here on the forum. Cheers

 

[jostalli]

It all depends on how you plan to use your van and what your energy needs are. For me I need all of the 600w of solar that is on my roof. If I'm parked for a few days I need solar to handle my energy needs so when the sun goes down I have full batteries to handle the loads overnight. The last thing I want is to have to start the engine. My loads are: convection microwave, induction cooktop, 12V A/C, led lights, fan, computer, phones charging, 1200w water heater, water pump.

 

[seapro]

Solar panels add wind resistance which reduces fuel MPG. I know the effect is small but at highway speeds i guess it might be at least a quarter of a mile reduction in MPG.

I go multiple nights (2 or 3) using only half of my 230 amp hours. I keep loads small. No A/C as I have 2 Maxxair fans one blowing in and one on exhaust to get a breeze through the van. No electric cooking and I have no propane aboard. I cook on a one burner stove filed by a butane canister. My microwave oven is a 750 watt unit without convection feature. I have no refrigerator as I use a super insulated top loading ice chest with a separate ice compartment. Consumption is 3 to 4 pounds of ice per day. I have a 750 watt Isotherm 4 gallon water heater. My cabin heat is via an Espar D2 heater running off a separate 10 gallon tank as my van is gas powered. Lights are, of course, LED.

 

[jostalli]

My three 200w solar panels are flexible. No wind resistance. You can't even tell I have solar panels.

 

[MsNomer]

In that case, they are going to heat the roof.

Two ways to approach the energy equation. More input or less output. Either way is fine.

 

[papab]

Finally. Someone who agrees with my reasoning re solar. I'm a true believer in the technology and for many/most people the van is a perfect application, but for much the same reasons you list, plus the debris that gathers on the roof when parked in our driveway under trees, just doesn't seem like it would work for us.

We have only 100 AmpHr house battery, but in three days sitting in the driveway in temperatures ranging from about 40° to 75° (the kind of temps we seek to hike in), fridge empty but running at 38° (worse case than full), we have used seven --that's s-e-v-e-n AmpHrs according to the TriMetric meter. LEDs and charging don't add much to that.

Wow, that's really low. What kind of fridge do you have? Does it have a freezer? My 4.3 cu ft novakool, with big freezer, in cool weather, avg current is about 1 amp, so for 3 days that would be about 70 amp hrs.

 

[MsNomer]

Engel MT45. I described it in the fridge thread a month or so ago. It is small by most people's standards, but holds more per volume because it is a chest. It can also serve as a freezer, but is not dual zone. Probably the single best decision I made in this build.

 

[RDinNHandAZ]

I guess my words somehow misstated my feelings about solar. I think it is the greatest thing since a flush toilet or mechanical refrigerator my nominees for best inventions ever! I love my 200 watts. I use it, in fact, I do not use the van's alternator except in unusual situations like days of rain. Flex panels are great taped or glued on, and the low mounted solid panels I have are a bargain, work forever, cool the roof in sun, and seldom need any cleaning. What's not to like? I have full batteries before noon each day, use all the electricity I want, and never worry about charging, driving, etc. We go to Anza-Borrega Desert Park in two weeks and will camp and hike for days. If I didn't have solar I would have to drive. NADA.
RD

 

[MsNomer]

Yep, solar is great when you like and can tolerate sun. We avoid it.