Hello all-

Has anyone made or found a 32v solar charger for their loco batteries?

I saw a thread here about Quick Charge 32V solar chargers, but I couldn't find the the product, and I already have one of their 32v plug-in chargers for when I have access to the mains.

This is for a GE 80-tonner, with no good access to power mains.

Thanks-

Mike

Probably not useful, but I found this thread on the "DIY solar forum" about boats with a 32v battery bank (which someone notes is similar to a locomotive battery system), I don't know if this will work for you but this company might have some ideas: https://diysolarforum.com/threads/solar ... uff.44824/
https://outbackpower.com/products/charg ... xmax-60-80

One can put several solar panels in series, e.g. two 12v in series = 24v. Now 32/12 doesn't come out even ... so I'm not sure. One would also need an appropriate controller between the panels and the batteries... all I've handled are 12v. Maybe you put multiple 12v controllers in series ???
I'd sure want to test that before I hooked up the expensive batteries...

-dc

Hey folks,
There are great solar charge controllers on the market that can be configured in the settings for a wide range of battery voltages. One of my favorites is the Midnite Solar Classic, linked below.

https://www.altestore.com/store/charge- ... er-p11901/

This charger can be configured to charge or maintain any battery from 12-72 volts. That means car batteries to full diesel locomotive batteries made up of a string of 8-volt batteries or dual 32-volt batteries.

I run one on an excursion caboose that doesn't have a generator, and it has worked like a charm for years. I have configured mine to charge as if the batteries are AGM-type batteries this sets the peak charge voltage to 14.4volts to avoid boiling off the electrolyte and not to affect any sensitive systems that may be connected to the battery.

The charge controllers aren't cheap, but they are far cheaper than new batteries!

I had a Midnite Solar Classic on our system here for several years. It finally "let the smoke out" one day and I have since replaced it with a Victron unit but I agree the Midnite is a pretty good unit.

It was my understanding that the 'modularity' of voltage in a photovoltaic array was at the CELL level, not the panel. I have been out of the actual loop in fabrication of these things for some time, so I don't know the degree to which you might 'cut up' nominal 12V panels and assemble a properly-safed 32V array from the sections, but it almost certainly wouldn't involve rocket science.

Keep in mind that "32V" isn't the actual voltage the charger would put out. Check your battery chemistry and charge control. The output "from" the charger ought to be regulated to match the state of charge of the battery chemistry, same as for chargers from plug-in electricity.

At the rate of charge necessary for locomotive batteries, consider connecting OTS panels in series and using a voltage-to-voltage converter of appropriate capacity to transvert the result to appropriate charging voltage.

There is a wide range of options for solar charge controllers. The most basic charge controllers (cheap) require the solar module voltage to be above the battery voltage to charge the battery - while an advanced (expensive) charge controller (like I link above) can boost or buck the battery charge voltage from any connected solar panel(s) to match your charging need plus optimize the solar input to maximize energy harvest.

There are also design considerations for how you arrange and size the solar panels, that is probably a topic for another thread.

At the charge controller level, these advanced controllers are pre-configured with optimal settings and have a user-friendly configuration screen that allows the settings to be modified to match whatever your application is. If you can feed it with DC voltage between 12-150V you can charge any rechargeable battery of any size with a charge controller like this with pre-programmed charge settings based on the battery chemistry the user selects.

For lead acid batteries, I err on the conservative side and program my chargers for AGM chemistry, it keeps the top-end charge voltage a little lower and isn't as aggressive when the charger tries to equalize the batteries. I also disable the auto equalization feature and set it to manually equalize only when I tell it to. This greatly reduces my battery watering needs and still provides enough power to start a diesel locomotive or to keep the lights on, radio working, and cash register running in a mobile ticket-taking or concessions application when HEP is not possible.

I have used these types of charge controllers to maintain batteries of many sizes. I connect it to maintain my tiny Fairmont M9 battery, all the way up to cell tower and radio repeater backup batteries. It is overkill on the M9 but just what the doctor ordered for bigger batteries - the point is that it is universal.

I do recommend using an input combiner box with DC circuit breakers plus a transfer switch if your DC sources have different native voltages. This will protect your circuit from faults and accidentally connecting two different sources to the same charge controller.

I am happy to help anyone design a solar charger to fit their application and budget, the recommendation above is the high-end option where the machine does all of the hard work for you, there are plenty of options for smaller scale or more budget-conscious boundary conditions.

Happy charging :-)

Everyone agrees that proper battery charging consists of three or four levels of charge rate. Initial bulk charge, taper down to finishing charge, etc. But the world isn’t always perfect and trying to design a perfect charger for locomotives isn’t necessary. The proof of this is the charging systems used on locomotives. They are strictly voltage regulators that pay no attention to the charge profile. Their goal is to apply a certain voltage to batteries regardless of what the charging current is. Most locomotives keep the batteries charged to 74 volts. Some RR’s use 75 volts and some go all the way down to 72 volts. Automobiles and trucks charge their batteries the same way. They use voltage regulators in the alternators.

So if you want to charge a 32 volt battery set, use a voltage regulator that can be set for 37 volts. Solar panels are not made to be cut up into sections in order to select just the correct number of cells. They are totally sealed units and won’t last long if those seals are broken.

Locomotives operate many hours per day for many days on end. And their batteries can last upwards of 10 years.

The key is to build a cheap 37 volt regulator and feed it with typically two solar panels wired in series that produce upwards of 50 volts total. The regulator then uses only 37 of those volts. But depending on the Sun angle and time of day, the solar panels never produce what they are rated for. But as long as they provide over 40 volts, the battery charger will be fine.

On a related topic, can anyone point me to a source for small 32v power supplies. We want to power several of the original 32v DC fans in our dining car, and need a proper DC source for those.

Greg

A few thoughts… Is the whole diner 32V? If you’re running 110/220V AC circuits, you could possibly change out the motors. AC motors have less parts to service or wear out. Or see if you can find an AC to 32VDC converter. You might find one for marine applications. Though if “marine” is in the description, it’s gonna be more expensive.

We are changing out all the lighting to 110V, but we really want to keep the original fans since they are original, fit, and work. :-) In the dining room, they are neat looking ceiling fans and in the kitchen they are odd shaped exhaust fans.

They is some who want to just install 24v power supplies and run with the reduced speed, but since the the fans are set up with resistor banks and 3 speed switches, it just seems a shame to not to use then as designed.

Ahhh. I thought you were considering exhaust fans. AC to 32VDC power supplies are available. You’ll have to figure out your total current draw of the circuit to size the power supply or supplies. Someone here may have already done something similar.

The answer is simple. Look for a 32 volt power supply on Amazon. There are numerous variable voltage power supplies there. Pick the one that suits your needs.

I just finished up moving our solar installation from a shed to our NYC caboose. I now have a bank of six 250W solar panels on the roof, angled to the south. Inside the car in one of the lockers is a Victron 150/35 charge controller, three Battle Born 24 volt 50 AH lithium batteries and a 120/240 volt inverter. The caboose now powers the main building and the rest of the site.

There is room for expansion with four more panels, two facing east and two facing west. A separate charge controller would be used to handle these four panels. At our site the sun comes up directly to the east, swings around to the south and sets due west. In the morning I will be able to get meaningful power from the two easterly panels until the main bank gets into the game, and by evening the westerly panels will pick up power from the setting sun.

There is also room for expansion on the storage side of things as well with room in the locker to easily fit three more batteries, perhaps more. Fortunately lithium technology is more tolerant of batteries of different ages working together so it will not be much of a problem to add batteries as money allows.