12v x12 battery pack 12v solar controller

[Adelie]

Originally Posted by john61ct

Doing triple DC to AC to DC adds no energy, will not help avoid PSOC

only **loses** energy due to greater conversion losses.

And think about it, how will one 12V unit store the energy to fill up a dozen of the same size?

Convert to Wh and do the math, if it isn't just 100% obvious to you intuitively.

The only actual energy sources here are

1. solar (poor)
2. genset (medium)
3. shore (ideal)

The boat is unattended and apparently on anchor so the only energy source that works is solar regardless.

The question is what can be done cost effectively.

Automatic system to isolate and charge batteries individually would be great but it would probably be an expensive custom job.

Solar panels in series would also work if there was an available controller with the appropriate input and output voltages. 12x 20w-30w panels would have plenty of juice to recharge the bank in a week. But sourcing the controller sounds expensive. Not as sure here.

That leaves running an inverter off of solar panels. All the parts should be off the shelf. The boat already has a charger. Maybe he needs another panel, maybe not, 2wk is a lot of time to recharge. The questions I see are:
A. Is a battery between controller and inverter really necessary?
B. How to limit charger draw so it doesn’t overload inverter or shorten its life?
C. Is some sort of cutout needed to turn charger on and off? Would a simple timer circuit work? If power to charger cuts off, when it comes back does it need intervention to restart charging or will it take up where it left off?

Yes there are more losses by running thru an inverter but I believe the goal is to minimise cost not maximize efficiency.

[john61ct]

I'm just clarifying the factors, the key issue is getting enough energy inputs.

The use case is pretty much set up to guarantee any effective solution will be complex and costly in any case, IMO it's probably easier to change those limiting conditions.

No need for solar panels to be put in series if they are properly selected in the first place.

The panel voltage does not need to be relevant to the battery requirements.

Putting lots of 20-30W panels are just silly when 250-350+W panels are common.

The Genasun boost SCs would be my starting point, but if their output needs to be upconverted anyway, then any collection of standard 24V ones will do.

I have no idea why you'd want to insert an inverter in the picture, AC power has no role to play here afaict?

[john61ct]

Originally Posted by Kburg55

Here is a link with the battery specs. I did most of my research but went with the lowest cost option.

Putting in electric propulsion requires either very deep knowledge or very deep pockets, ideally both.

Save your money so after this bank's worn out you get something better, likely cheaper too, I assume you aren't in mainland China?

> My charger on shore power gets a voltage runaway effect after full charge. It hits 192v at less than 1 amp.

Is it too late to get your money back? Not fit for purpose unattended, you must be present to regulate it manually.


> Ideally I could buy a new charge controller that has solar as well as ac input and is constant voltage output

Fantasy land.

Your time spent at Bulk / CC vs Absorb / CV is not up to the charge source, just depends on SoC, chemistry resistance and amps rate.

It needs to hold CV after the setpoint is reached, not allow any higher under any circumstances, and needs to have an adjustable Hold Absorb timer, unless stop-charge is based directly off the current taper (endAmps)

> Is it possible to use a dc-dc in the same circuit as the ac-dc charger.

Anything is possible with the right electrickery knowledge set.

As I said above, you really need to be in a techier DIY EV-oriented environment.

Your biggest hurdle is those very rarely bother with lead at all anymore, and access to grid mains is assumed.

The combination of off-grid, the high voltage, low-CAR legacy chemistry, your desire to charge unattended for weeks at a time, are all just such an "unusual" set of outlier difficulties, IMO you really should spend a lot more money and get a professional involved.

Kludging something cheap & unconventional can be made to work, but the bank will get murdered pretty quick, and you could easily cause fires or even an explosion.

[Kburg55]

I guess the best solution is to make sure I am charging up for as long as possible when returning to dock. And most likely invest in 144v solar...



With the original batteries the previous owner would run the generator and the charger while underway as to charge and run in hybrid mode. What are your thoughts on this. Does that cause more wear on the batteries? as the current has to flow through the battery to reach the motor.



These batteries are to tide me over till the next energy revolution. But the solar tender will be necessary to maintain them till then.



Thanks again for your help!

[Adelie]

Originally Posted by john61ct

I'm just clarifying the factors, the key issue is getting enough energy inputs.

The use case is pretty much set up to guarantee any effective solution will be complex and costly in any case, IMO it's probably easier to change those limiting conditions.

No need for solar panels to be put in series if they are properly selected in the first place.

The panel voltage does not need to be relevant to the battery requirements.

Putting lots of 20-30W panels are just silly when 250-350+W panels are common.

The Genasun boost SCs would be my starting point, but if their output needs to be upconverted anyway, then any collection of standard 24V ones will do.

I have no idea why you'd want to insert an inverter in the picture, AC power has no role to play here afaict?

Solar panels need to be in series if the solution is a controller that doesn't boost. That's the point of having 12x 20w-30w panels, to get the desired voltage to the controller without taking up too much real estate. If there isn't a controller that will output for a 144v bank it's moot.

The Genasun booster SCs will only charge up to 48v. The OP's existing system is 144v. If there is another booster that will work with a 144v bank then great, otherwise time to look for another solution.

Using an inverter is a way to deal with the voltage stepup using the existing charger. Though it sounds like it's not the greatest charger and needs to be replaced. Once again efficiency is not the main goal, cost is provided the system can stop and start daily.

The decision to use a 144v bank and motor probably was done for good reasons at the time, but without consideration of the future, i.e. now when the mooring situation has changed.

All of the charging solutions discussed here involve AC, whether it is overt or not. MPPT controllers involve AC as an intermediate step as do DC-DC converters

What's "afaict"? Forum rules say to use English.

[Adelie]

Originally Posted by Kburg55

I guess the best solution is to make sure I am charging up for as long as possible when returning to dock. And most likely invest in 144v solar...



With the original batteries the previous owner would run the generator and the charger while underway as to charge and run in hybrid mode. What are your thoughts on this. Does that cause more wear on the batteries? as the current has to flow through the battery to reach the motor.



These batteries are to tide me over till the next energy revolution. But the solar tender will be necessary to maintain them till then.



Thanks again for your help!

Investing in 144v solar is fine if you can find a 144v controller. I've browsed and not found anything. Doesn't mean it's not out there, but it doesn't strike me as being a very high volume product if it is made and thus is likely to be expensive.

The next energy revolution is likely 20yr away so I wouldn't hold my breath.

[john61ct]

As far as I can tell.

There is no solar controller that boosts that high.

And again, the panels could be at 140V or only 50V without being in series, does not matter wrt the voltage output of the controllers.

As I stated DCDC boost conversion is needed anyway, so going from 24V should also be included rather, than only looking at 48V.

Propulsion does routinely need to be at much higher voltages than House storage, but DC conversion is normal, many EV, telecom and industrial systems use ~300Vdc as a backbone and use buck conversion into battery systems at the POL point of load.

So the voltage is really not the major issue, the other aspects I pointed out are all much bigger obstacles.

[john61ct]

Originally Posted by Kburg55

I guess the best solution is to make sure I am charging up for as long as possible when returning to dock. And most likely invest in 144v solar...

Does not exist afaik. Again, DC conversion will get you there, as is common in many domains but never cheap done properly.

The DIY EV and Endless Sphere guys can help more, see caveats above.

> With the original batteries the previous owner would run the generator and the charger while underway as to charge and run in hybrid mode.

Yes that's fine, but with lead you need 6-7hrs to get to Full even with kW of power available, above and beyond your engine load.

If you're at 85%+ SoC when you get to your mooring, then a smaller amount of solar will be able to finish the long tail, take another 5-6 hours, but unattended? more difficult and expensive.

> What are your thoughts on this. Does that cause more wear on the batteries? as the current has to flow through the battery to reach the motor.

Nothing goes through the batteries, only current left over after the engine loads is available for charging.

If you're willing to set up quick-connects for intra-bank 6x solar controllers @24 each would work, break the bank apart end of your voyage out, put it back together before the next one.

Then you're dealing with standard consumer-grade gear, under a couple grand might get you there.

[Kburg55]

Well back at the boat and trying to figure everything out still, think I figured out the problem with the ac charger... Blown fuse... Most likely from previous battery pack.
My house solar is an old school solid state that says it is field adjustable but I still need to open it up and up the charging voltage.



Been doing some research and found a 144v solar charge controller.

https://m.alibaba.com/product/60677259575/Hot-Sale-144V-30A-Solar-Charge.html
Not sure if I want to take that leap yet, need to map out panels and see what I will need.


Thanks again for pointing me in the right direction.