Solar powered trickle charging.

[Kappy]

Hi
Been awhile since I've been on here, been running around the country house minding.
Back in WA and looking for a solar solution to keeping numerous batteries charge.
While I'm away I have several batteries on trickle charge/maintainers, however my landlord keeper turning the power off and I end up having to replaced expensive batteries.
So looking for some guidance to set up a cost effective, safe, set and forget solar system(if that's possible} to maintain trickle charge for about 5/6 batteries.
About 3 large car batteries approx 95 ah and several smaller motorcycle style batteries.
TIA
Cheers
Kappy

[Keith Morris]

"tanks" here-----Kappy,
Good to hear from you again. Your problem is easily fixed.
1: Replace the housekeeper.
2: Contact T-1 Terry.

Keith.

[T1 Terry]

"tanks" here-----Kappy,
Good to hear from you again. Your problem is easily fixed.
1: Replace the housekeeper.
2: Contact T-1 Terry.

Keith.

not interested in house keeping Keith
Now for the proper answer. I'm assuming we are talking lead acid batteries here.
You will need to read the whole thing because I was thinking while one finger typing and came up with a better solution after I'd typed the first bit

If you just want to maintain the batteries fully charged, you will have a problem with electrolyte stratification .... I think that's a word Basically, the acid is not being stirred up by the bubbling and the strong mix ends up on the bottom and the water on the top, each wrecking the plates in their own way.
Top of the line mains chargers have a storage function that actually does the full charging cycle every mth or so to keep the acid mixed, the rest of the time it holds them at a voltage lower than the point where any charging will occur, but high enough to replace the loses that are inherently part of the lead acid chemistry.
About the best solution I can come up with is to buy a pure wave inverter, connect it to the biggest capacity battery and connect a solar panel to that with a simple controller that will hold it at 13.8v while the sun is out. Plug the mains charger into the inverter and attach cables that spiderwebs across the other batteries, each one from the charger itself and not just the batteries linked in a daisy chain from one to the next. Set the charger to maintenance charging and all should be well with the world when you return ...... hopefully The catch is, any one battery can drop a cell and drag all the other batteries down with it till they are all dead. You could add a diode in the positive of each battery and just use the main battery as the voltage sensing battery with no diode in the cabling ..... a bit agricultural, but it would do what you want .....then the damage, if any, is limited to the failed batteries.

The other alternative and maybe the better choice, is to just link the batteries from the biggest battery as above, use the diode in the linking battery cables to keep them from discharging each other, and put a better quality solar charger on the big battery so it cycles each how ever long. The Dingo 20/20 is a good choice for this because you can set how many days before it returns to the boost stage and then goes through the cycles .......

How was that, clear as mud

T1 Terry

[Kappy]

Since posting an interim idea popped into my head.
Thanks.
I run the trickle/conditioner chargers I have off my bus solar system, they shouldn't dent my lithium set up, should theyY
I mostly have little Ctek chargers that are .8 to 1.5 amp conditioning chargers.

You sorta lost when you started taking diodes.

Maybe more research in the future.

[Dot]

Simple, disconnect the batteries. Nice to see you back after a longish time.

[T1 Terry]

Simple, disconnect the batteries. Nice to see you back after a longish time.

Depends how long before they will be reconnected and charged Dottie. 6 mths is about the limit, they will have self discharged to the point of damaging themselves if left any longer.

Yes Kappy, that fits into idea one, but separate chargers for each battery will work even better than the spiderweb of cables to link all the batteries to the one charger and diodes in each positive cable. A diode is just an electrical one way valve, the charging can go through the one way valve(diode), but discharging can't return through the one way valve(diode) The silver line on the end of the diode indicated which end has the blocking gate, the charge can go from the no stripe end through the silver stripe, but not back the other way
https://components101.com/diodes/1n4004 ... equivalent
Jaycar or any electronics shop carry these items and they are cheap

T1 Terry

[Kappy]

Thanks Terry

I plan on using these style conditioning chargers.
https://www.supercheapauto.com.au/p/sca ... r&start=12
https://www.amxsuperstores.com.au/motor ... rger-xs0-8
Do I still need to fit diode, both claim set and forget.
The Ctek I've used long term before.
at .8amp they shouldn't damage my Bus solar set up should they?

[T1 Terry]

These are basic maintenance chargers, they do not have a programmable return to boost function so the acid mixing will not occur, they might remain at a charged voltage, but without the acid being remixed they will slowly destroy themselves.
If you had a timer that would turn off for a week, then on for a week and so on, you could use that to power the CTek chargers.

If you had a Victron Multiplus inverter, they have an aux battery charging circuit as part of the build with a 4 amp outlet that is designed to keep the start batteries charged over a long free camp.

The down side with using mains maintenance chargers, they have a history of going crazy and charging the battery at bulk mode voltage until it is destroyed, more than one motorhomer has discovered this happening when they go to move the vehicle out of the shed, destroyed start batteries.

Personally, I'd go with the Plasmatronics Dingo using the program 4 menu and setting the float voltage at 13.1v and return to boost every 60 days so the acid remains mixed.

You would only need one and network the cables to all the other batteries from there ..... do you have them close together?

If you want, I can build the basic set up and you can connect each set of battery charging leads from there, would that help?

T1 Terry

[Kappy]

Thanks Terry,
What would that look like size and $$$ wise.
I will evaluate my needs when I return home next week and start planning the future.

[T1 Terry]

Thanks Terry,
What would that look like size and $$$ wise.
I will evaluate my needs when I return home next week and start planning the future.

Do you have the 12v nom. solar panels? (VMP 17 to 18v) open circuit voltage 21v to 22v

T1 Terry