Small automatic solar charger?

cadillackid · 12-28-2019, 09:02 AM

part of my RedByrd build is installing the glass cockpit (fully glass switch panels ,etc)..

"Renote start" is also part of the project. this project entails having a telematics system running 24/7 which will allow me to monitor the bus and also turn on / off the webasto. and probably eventually the engine if I choose. (some safeties need installed for that to work).

anyway my aim is to have a secondary AGM deep cycle battery with an isolator which is charged from the alternator when the bus is running, or be charged via a battery-tender built-in if my engine block heater is plugged in.. I have a nice little battery tender with a charger-controller built in that works from shore power so when im plugged in things are good.. I need something like that for solar.

however for those times im road-tripping and my bus may sit outside for a few days at a time.. im looking for something to bolster the battery..

a small solar panel i can mount someplace pretty easily outside or leave it in a windshield, etc..

what is out there where i dont need to buy inverters and charge controllers and special panels / battery banks.. is there any type of Good automatic all-in-one type device that will do a decent job for what I want?

im still working out the details on power usage.. I need to do more studies on the cellular portion of it to get a handle on just how much juice ill be pulling in an idle state.

for anyone that doesnt know me. this bus doesnt go campng and i dont live in it.. so im not looking for ways to power lights, stereo, TVs, etc.. just give a bolster to the secondary battery.the bus is my roadtrip mobile, grocery getter, and Super-Duper espresso-shop-locater.. its fully seated and will stay that way..

lets see your ideas!

-Christopher

john61ct · 12-28-2019, 01:31 PM

Charge controller is required, every solar controller is automatic, you do not mention any relevant factor.

MPPT extracts more efficiently, bit more cost, can work with the more efficient high voltage panels.

We need more info to get more specific, starting with your panels, bank battery model, ideally links.

Otherwise just voltage of your bank, wattage and VoC ratings of the panels, feature sets, brands and cost.

Victron MPPT SmartSolar are great value.

None of this has to do with how you use the energy, inverters etc.

But if you have no need for a House bank, then just beef up your Starter, use solar to keep it topped up when sitting away from mains.

PNW_Steve · 12-29-2019, 01:23 AM

https://www.amazon.com/Battery-Tende...82857521&psc=1

cadillackid · 12-29-2019, 07:55 AM

Quote:

Originally Posted by john61ct

Charge controller is required, every solar controller is automatic, you do not mention any relevant factor.

MPPT extracts more efficiently, bit more cost, can work with the more efficient high voltage panels.

We need more info to get more specific, starting with your panels, bank battery model, ideally links.

Otherwise just voltage of your bank, wattage and VoC ratings of the panels, feature sets, brands and cost.

Victron MPPT SmartSolar are great value.

None of this has to do with how you use the energy, inverters etc.

But if you have no need for a House bank, then just beef up your Starter, use solar to keep it topped up when sitting away from mains.

the main reason to have a separate bank is that the computer will be on constantly.. (arduino or pi zero not sure which yet for the core).. if for some reason I dont have enough sun (or shore) to make more power than I use i dont want to kill off my starter batteries.. so ill have a single smaller battery (because it fits in my battery box) that will be just for the purpose of running said accessories.. im using a standard "car type" AGM battery as it is made to be charged with an alternator and can be cycled lower than a standard lead acid. my main starter bats are also AGM.. however the T444E engine is notorious for not starting (even though it cranks at a decent speed). when the batteries are low..

I just didnt know if there was some type of nice all in one device or set which is already made for what I want to do.. vs sourcing a panel and the proper inverter (do I need one?) and charge controller.

so far in my calculations my peak electrical usage in idle mode will be 10 watts..

most of the consumer devices on amazon, etc seem to be anywhere from 2-10 watts peak.. so im guessing i need to do something along the lines of steve's post..

in that link you can get a "bought together" with a 30 watt monocrystaline panel.. is that the wrong type of panel to have? it looks like perfect size to mount to a bus roof and not affect driveability or MPG's too much.

-Christopher

john61ct · 12-29-2019, 12:10 PM

Nothing you are talking about has anything to do with an inverter.

A panel and solar controller are all that you need to get started.

Quote:

Originally Posted by cadillackid

so far in my calculations my peak electrical usage in idle mode will be 10 watts..

most of the consumer devices on amazon, etc seem to be anywhere from 2-10 watts peak.

Peak schmeak, measure your "needs to always be on" loads' consumption,

in total Ah per 24hrs, with a coulometer like Watts Up.

If it is on a similar scale to the vehicle ECU, just add some solar no need for a separate battery.

Or if you do, then you need a VSR / ACR, might as well move the ECU to that side too, leave Starter batt completely isolated except when solar is charging when vehicle is not being used.

Use a proper deep cycling battery for that, and only AGM if really necessary, otherwise poorer value than FLA.

cadillackid · 12-30-2019, 03:35 PM

john, what is a proper deep cycle battery? I always thought AGM was that? they state "AGM deep cycle" when ive bought them..

so inverter is only necessary if I want to change voltage or run AC (120VAC)? otherwise since im looking to run everything DC a charge controller is my main need?

so im building for 10 watts continuous.. if it ends up lower, great my batteries last longer.. obviously im going to run bigger than 10 watt solar as how often do you really achieve peak out of a panel? i live in ohio.. we have below 32 degree sun angle 1/4 of the year and way too many cloudy days.. if im in sunny florida im not likely looking to remotely start up my webasto heater..

im not going to put the engine ECM on the second system.. low voltage to that ECM is something they really dont like.. in fact it makesd engine starting all that much hardfer if you kill the batteries on a T444E / DT466E ECM.. it will be a secondary battery. now the webasto will be on the starter bank.. you typically omnly run that a couple hours at a time.. my isolator could be made to pull back in if my sercondary battery charges to completion.. thus putting a top charge on the starters..

but really start simple and build up is my mantra..

-Christopher

john61ct · 12-30-2019, 08:55 PM

Quote:

Originally Posted by cadillackid

john, what is a proper deep cycle battery? I always thought AGM was that? they state "AGM deep cycle" when ive bought them.

99% of vendors are fraudsters in this market. 99% of AGM batts are only good for cranking, aka Starter batts.

If you really need AGM, stick to Lifeline, Osyssey or Northstar, can trust them. But FLA last longer better value: Rolls/Surette, Trojan, Deka/East Penn, U.S. Battery, Crown, Superior.

The best battery value by far is Duracell (actually Deka/East Penn) FLA deep cycle golf cart batteries, 2x6V, around $200 per 200+AH @12V pair from BatteriesPlus or Sam's Club. Deka labeled same batts also sold at Lowes.

https://marinehowto.com/what-is-a-deep-cycle-battery/

Yes inverter is for loads need 120vAC

Solar controller is to charge battery from panel.

Consumption is measured in 12V Ah per 24 hours, need to put back in 10-20% above what you take out, and ideally battery gets back to Full 100% SoC each day.

Panel rated for 100W will contribute about 25-30 Ah per day in ideal conditions.

A Webasto could easily use 60-100Ah per day in winter, half that if just overnight.

Best to actually measure with a Watts Up type coulometer.

If you have a House bank do not put **any** load on Starter, save it for cranking only, never gets run down at all so doesn't need even 0.001% what the House bank does.

Use a VSR/ACR combiner, not a cheap isolator.

It joins the two circuits only while charging is active, from either side.

o1marc · 12-30-2019, 09:17 PM

Quote:

Originally Posted by john61ct

The best battery value by far is Duracell (actually Deka/East Penn) FLA deep cycle golf cart batteries, 2x6V, around $200 per 200+AH @12V pair from BatteriesPlus or Sam's Club. Deka labeled same batts also sold at Lowes.

Actually they are a better deal than that. They are $98.99ea at Costco, and are 210AH ea. So for $200, you're getting 420AH@12v.

john61ct · 12-30-2019, 11:46 PM

Nope, AFAIK Costco's suck, not a Deka product, made by JCI not even a proper deep cycling line.

I have heard of people scamming their warranty though

PNW_Steve · 12-31-2019, 12:57 AM

Quote:

Originally Posted by o1marc

Actually they are a better deal than that. They are $98.99ea at Costco, and are 210AH ea. So for $200, you're getting 420AH@12v.

New math?

4 x GC2's will yield 12v 430 a/h and would cost closer $400.

For $200 you could buy two and have a 12v - 215 a/h bank.

Series - voltage is additive. Amp hours stay the same.

Parallel - voltage stays the same and am hours are additive.

john61ct · 12-31-2019, 02:24 AM

That too

8-D

cadillackid · 12-31-2019, 06:44 AM

great read John!!

my big issue is SPACE.. i dotn have the space for 2 golf car batteries.. I dont want to put flooded batteries inside.. then I need to build an enclosure, vent it and of course lose seating space (remember my bus still has and will have its seats.. its not a camper or a house)..

I have a 3 Group-31 battery box.. and some of that space is used for the transmission electronics.. I realistically have room for a group-24 battery.. thus why I plan to run ONLY the internet-connected computers from it...

realistically this is a battery i can fit.

https://www.trojanbattery.com/pdf/da..._12_170_DS.pdf

The webasto - the pl;an is not for it to be running all the time.. the design is the computer to be running all the time and I use my App to turn on the webasto an hour or 2 before i drive the bus.. in my short bus, the webasto circulates heat through the engine and through the heater loops.. since no fans are on and the engine thermostat is closed it warms the system up within an hour to 140 degrees or so from 35.. more than enough to have easy starting and instant heat. assuming in this scenerio the webasto runs on high it pulls about 4 amps (except about 9 while its glowplug is lit to fire the heater which is maybe a minute)..

John - is something like this a good one for a proper isolater / combiner?

https://www.victronenergy.com/batter...tery-combiners

the "house" bank is only for things that need to run when the bus is turned off.. so yes it may make sense to run the webasto off that bank.. but on the 444E engine, there is a circuit that measures voltage going to the starter itself when cranking.. (it will throw a code if its low).. separate power sources and possible voltage potential between the 2 is a good way to blow up the detection circuit in the ECM.. so i want to keep all the engine-trans-starter circuits across one bank.

-Christopher

o1marc · 12-31-2019, 11:33 AM

Quote:

Originally Posted by john61ct

Nope, AFAIK Costco's suck, not a Deka product, made by JCI not even a proper deep cycling line.

I have heard of people scamming their warranty though

It's an Interstate battery, they don't suck.

john61ct · 12-31-2019, 12:39 PM

Well JCI is the maker of Interstate's relabeled batteries. They aren't great, for true deep cycling usage, Deka's are much much better.

Are you saying the ones at Costco are actually labelled as Interstate?

PNW_Steve · 12-31-2019, 12:57 PM

I am a fan of the GC-2 FLA batteries when it comes to the best value considering capacity, longevity and cost.

Given your space and location limitations you may want to consider AGM. For a given usable capacity they are smaller than FLA and can be safely used inside.

Take a look at :https://www.wholesalesolar.com/99601...6v-agm-battery

cadillackid · 12-31-2019, 02:22 PM

is the trojan Smallish FLA I linked, a good candidate? it is in a package I can handle and is 12 volt so I only need one..

o1marc · 12-31-2019, 03:38 PM

Quote:

Originally Posted by john61ct

Well JCI is the maker of Interstate's relabeled batteries. They aren't great, for true deep cycling usage, Deka's are much much better.

Are you saying the ones at Costco are actually labelled as Interstate?

Yep, I have 4 of them.

https://www.costco.com/interstate-6-...100476406.html

john61ct · 12-31-2019, 11:02 PM

Yes, and 150Ah is a decent capacity if you start running heavier loads. But then you'll want 100-200W of panel, still a pretty small system.

But overkill for just counteracting ECU & self-discharger. If you do end up getting multiple panels, ideal is if they all match.

A Victron 75/15 gives a fair bit of flexibility, up to 220-250W for ~$120

cadillackid · 01-01-2020, 06:22 AM

Quote:

Originally Posted by john61ct

Yes, and 150Ah is a decent capacity if you start running heavier loads. But then you'll want 100-200W of panel, still a pretty small system.

But overkill for just counteracting ECU & self-discharger. If you do end up getting multiple panels, ideal is if they all match.

A Victron 75/15 gives a fair bit of flexibility, up to 220-250W for ~$120

defimitely a small system.. remember the bus isnt a camper, I dont sleep or live in it.. it has no capabilities for "life" other than being on the road.. so the solar system is purely to maintain the internet connections and run the webasto for an hour or two max before I drive the bus.. if I were building a Camper I would definitely go with a larger solar system.

-Christopher

john61ct · 01-01-2020, 06:38 AM

Then a 200W panel + controller with that battery and some sort of combiner/VSR/ACR would work perfectly.

Assuming you also wanted the Starter batt charged by the solar, and House also charged from the alternator while driving.

Side benefit, House loads can't pull Starter SoC down below cranking level.

A Ctek D250S Dual unit might act as controller + combiner (actually a DCDC charger) and save a little money, but its SC is not great and 14.4V output a bit low for that Trojan.

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