bought an EverStart Maxx 29 DC and the Noma 80w crystalline solar panel kit

[Homeless in Canada]

I'm only using the battery to power a 17 Watt 120 volt LED light bulb and a phone charger through a small 60 watt rated cigarette socket type inverter 

 I used the battery for a few evenings and charging it during the day by a 2 amp battery charger that I had running off the inverter as I was driving to jobs but after a couple of nights the light LED light would start to flicker on and off so I guess the charger wasn't doing the job

I got a different battery charger a noco genius 7200 but I think it draws too much power for the little inverter. I had access to shore power for about four hours during which I had the battery charging off the genius charger and the light was good again however the Noco charger never went above 25%

 so I got an 80 watt Noma solar panel kit. I chose this one because it came with the charge controller and a bigger power inverter it says it's for medium and large applications.

I have the panel out in the sun hooked up to the battery and the voltage on my multimeter reads 12.13 which is up from 12.06 just a few minutes ago so I guess it's working.

 if I disconnect the panel the battery voltage is 11.98 also up a few hundredths of a volt since I tested it a little while ago.

So if my battery voltage is 11.98 how far did I deplete it? And is there any yusin rigging up the genius charger to run off the alternator while I am driving? I have days where I'm driving to jobs all day long and don't really have time to set up the solar panel and other days where I'm not driving I don't really feel like running the engine charge my battery

 

[jimindenver]

You depleted it a bit over 50%, much lower and the inverter would shut off.

The most important thing is that you generate more power than you use be it by solar or else wise. A 2 amp charger would take at least 25 hours and even that is wrong because it takes a certain amount of power just to keep the battery from losing voltage. Unfortunately a 85 watt panel is not going to put out much more than the charger. Combined it would take days to recharge the battery and that's only if you did not put any loads on it.

You need more power.

So once you get the battery fully charged back up...in a few days, you can start seeing it as producing more power than you consume. Your 80 watt panel is rated for 4.4a and you are not going to see that due to the 30% loss of a PWM system. Closer to 3 amps to the battery in the end. Now you would think that a 85 watt panel and a 75 watt light would be a good match but the thing is the light is actually 75 watts PLUS what it takes the inverter to create the power (close to 7 amps) while the panel does not actually give you 85 watts. So while your panel puts out 3 amps a hour, it takes over 2 hours of full sun to cover one hour of running the light. That does not include the phone charger but it is a example of how to understand the concept of power in/ power out and the balance between them.

I would suggest getting a second panel but seeing the price of the kit I think there may be a more cost effective means. There are solar lights that can be quite bright and even charged off of a USB cord just as your phone can be. This would not only get rid of the inverter but you would also be able to charge them off of a USB adapter in your cars 12 volt port or another connected to your battery/solar system. It's always easier to use less power than it is to create more.

Should you go the more power route you could get another 80 watt panel or even a inexpensive 100 watt as long as the voltage is similar. (yours is 18 volts) Output would still be under 8 amps so you could continue to use the same controller. Even so I still suggest a less power hungry light.

The last thing, and this may be controversial but your battery is dying sitting there at such a low voltage. The longer it is like that, the more damaged it becomes. You need to get some serious charging going on as soon as possible. I do not know anything about your vehicle so you may need to check it out first but the last time I was in a similar situation I put a set of jumper cables between the trucks battery and the low battery and then run the truck. You might even want to keep the RPM up a bit because at idle your alternator doesn't put out its peak and running the vehicle takes a fair amount of the alternators output. You can't realistically charge up the battery fully this way but you might get enough back into it in a hour that the solar has a chance of catching up.

There are reasons why doing this is not idea but you are not trying to get the optimum output, you are trying to save your battery.

 

[Homeless in Canada]

I have some heavy Gage battery cable I could hook the house battery up to the alternator or would it be better to run the genie battery charger off the alternator while I'm driving I could do it either way

 

[jimindenver]

You can make a simple manual battery isolator by grounding the house battery and running 4 AWG cable + a switch and fuse between the two positives. I suggest a 12 volt circuit breaker because it acts like both a switch and a fuse. That way you can turn the switch on after you start the vehicle and off to keep from draining the starting battery.

If you are talking about doing it instead of the jumper cable thing but without the switch/fuse for brevity, I can not support hard wiring without at least a fuse.

On the Genie charger. At 2 amp it is too small to be of any serious use. You really do need some serious charging right now.

 

[DannyB1954]

In my van I am using the same battery, (actually two of them). I have solar but also charge through a solenoid from the alternator when the van runs. Solenoids are cheap. Get the continuous duty type though. The momentary types are made for heavy amperage for brief periods. If you leave them on a long time they will heat up and burn out. I use this one https://www.amazon.com/gp/product/B008R1T5IM/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1
from the battery I run the power to the solenoid through a circuit breaker. I used this one https://www.amazon.com/gp/product/B01CZDAQEY/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1
You will also want to put one on your house batteries. This way if the wire in between shorts both sets of batteries will shut off.

On the wire in between use the heaviest gauge that you can find. The reason is the thinner the wire is, the more electrical resistance there is so the voltage drops. When charging batteries this is not a good thing. To charge the voltage needs to be higher than the battery. Usually 13.8 volts. Using small wire the voltage at the house battery may be too low to fully charge the battery. I found that buying jumper cables and cutting off the ends is cheaper than buying the wire. I use the Walmart 4 ga. 20'. They go for about $20. These are actually aluminum that are copper plated but they work just fine. I get the terminals from the electrical department I use the type that tighten with an allen screw. If they ever need to be taken apart and cleaned it is very doable.

To protect the wires I run them through the black irrigation hose that they sell cheap in the garden department.
Here is a video a lady did when I installed a solenoid system in her van.

 

[Homeless in Canada]

the Noco genius charger puts out 7.2 amps and stops charging when the battery is charged. It only draws 150 watts so I'm thinking it might be possible to rig up a slightly larger inverter and run it off the cigarette lighter

I've got the charger and Battery plugged in at my storage locker now I'll leave it here overnight so the battery gets a good charge

https://no.co/g7200

 

[DannyB1954]

the Noco genius charger puts out 7.2 amps

Lets say that battery has 100 amp hours of energy. If you use half that, you have used 50 amp hours. That charger in an hour will put out 7.2 amp hours.To put back 50 amp hours of power it will need to charge for 50amp hours/7.2 of charging = 6.9444 hours.

If you charge it off of your alternator that puts out 50 amps, it will take you 50 amp hours/50 amps= 1 hour. These are just ball park figures, but that is how the math works. If you drive an hour during that day to get to town and back, your battery got charged with out any effort on your part with a solenoid system.

Anytime you convert energy you will waste some in the process usually in the form of heat. With your charger, you are converting 12 V DC to 120 V AC, then back to 13.8 V DC. Energy will be lost in both the inverter and the battery charger. Watts is volts times amps. 150 watts / 12 volts = 12.5 amps. You are using 12.5 amps of power to charge a battery at 7.2 amps. See how the loses add up? and it is taking you the better part of the day to do it.

 

[Homeless in Canada]

I have a cargo trailer and the cost of running heavy gauge battery cable from the alternator to the trailer where I use the battery is prohibitive.

The most practical is to carry the battery from the side door of the trailer and place it in front of the passenger seat every morning. I can run a few feet of battery cable through the firewall and then charge the battery directly off the alternator or using the charger.

My follow-up question then is how do I know when it is time to stop bulk charging directly off the alternator in order to avoid overheating the battery. Do I just feel it with my hand or is there a voltage at which it is recommended to switch to the solar panel or a lower amperage charger.

 

[B and C]

The voltage regulator of the alternator takes care of the voltage when the battery is gets full just like it does for your engine battery.

 

[Homeless in Canada]

After leaving the battery on the charger all night the voltage is 13.18.

If the 120 volt LED light bulb uses 17 Watts and I'm running it on a 60/75 watt inverter what is the actual power consumption?

on the inverter it says input 12 volt 8 Amp Max. And a maximum output of 75 Watts for 5 minutes. So am I correct in assuming that the inverter is using about 96 Watts to deliver 75 Watts. So the power loss is approximately 33%?

17 Watts / 12 volts is just under 1.5 amps. With a 33% power loss my light bulb is consuming two amps per hour.

 

[B and C]

You need to get rid of that 120V light bulb. A 12v LED light can give a lot of light for a lot less power.

 

[jimindenver]

13,18v on the charger or off?

13.18v while still connected to the charger means the battery is far from full. 13.18v off of the charger and having set for a hour or two, (preferably 24 hrs) is a good full resting voltage.

FLA batteries are not full in a hour if they are 50 amps down and you hit them with a 50 amp charger. It doesn't work like that. The battery will accept the full output of the alternator/charger until it reaches 85-90% full and then it starts tapering the acceptance rate. That last 10-15% takes forever. Those last few amps can be provided by your charger or even the 80 watt solar panel. Had you used the jumper cables for a hour first and then over night on the charger, the battery would stand a better chance of being full.

By the way. Jumper cables, a isolator or solenoid all do the same thing but with different gear. I suggested the jumper cables because they took no building or buying of gear and would have allowed you to get the battery back up, stopping the damage that will continue to happen until the battery is returned to fully charged.

 

[Homeless in Canada]

13.18 volts off the charger.

So how do I know it is time to stop the bulk charge with the jumper cables and switch to the solar panel for the top off

 

[jimindenver]

You would need a amp meter or DC clamp meter to know when the absorption rate was tapering to the point that the solar panel could take over. As it is a hour should be enough to get the voltage up enough to give the solar a chance.

 

[DannyB1954]

I have a cargo trailer and the cost of running heavy gauge battery cable from the alternator to the trailer where I use the battery is prohibitive.

The most practical is to carry the battery from the side door of the trailer and place it in front of the passenger seat every morning. I can run a few feet of battery cable through the firewall and then charge the battery directly off the alternator or using the charger.

My follow-up question then is how do I know when it is time to stop bulk charging directly off the alternator in order to avoid overheating the battery. Do I just feel it with my hand or is there a voltage at which it is recommended to switch to the solar panel or a lower amperage charger.

If the alternator is charging your battery, it will not over charge. It has a voltage regulator that keeps the voltage below what would harm a battery. When you are done driving just put it on the solar system.

 

[greeneyedggirl]

If the alternator is charging your battery, it will not over charge. It has a voltage regulator that keeps the voltage below what would harm a battery. When you are done driving just put it on the solar system.

Just if anyone cares, Jim in Denver (http://jimindenver.com/) is a seasoned, experienced installer of complete power systems.  I met him this year at the RTR and then spent a bunch of time with him while he was helping other people in our Caravn get solar installed, or even repaired (one woman's rig was a complete mess) and he's really good at what he does.  His own setup is impressive and a joy to see because he thought of everything, even has his rooftop solar on a tilt/swivel so that he can get maxs power froim the sun.  

So he's not just another person with an opinion and questionable knowledge, he's a professional that does this for a living. It's great to have him here, and if you follow what he says, you'll have a great system you can count on!

 

[highdesertranger]

Jim who? hahaha just kidding, great guy. highdesertranger

 

[Homeless in Canada]

I got a 12 volt light bulb screws into a standard light socket. Battery is doing much better only takes a couple of hours with the solar panel to get a good charge.