Uhaul solar and lithium

[kombiguy]

Progress continues, as do questions. New Lifepo4 battery, shore power cord, and PD4045 power center. While doing all the electric, I found that the original solar panel was producing 12 volts in sunshine. I have no idea how to figure out watts or amps. The real question is how do I connect the solar panel to the battery? Do I need a solar controller, or can I just connect it straight to the battery?

[mary and bob]

The original solar panel had a very small output as it was only designed to maintain the battery when the trailers sat on the rental lots. It had a controller that was attached to the battery box. Best to toss it and maybe use the original mounts for a good modern panel.

[kombiguy]

That seems to be the general school of thought. I'll probably get rid of it and just use my portable panels. Thanks!

[Motoboss]

With a new lithium battery you’ll want a controller and a modern solar panel. You can use a suitcase style that has a controller built in so it connects to the battery and ease of movement to follow the sun. If going hard mounted a typical wiring set up is solar panel to controller, controller to battery.
Additionally, typically you’ll want 200 watt solar panel for every 100 amp hour battery, although 150 watt panel seems to surfice.

[kombiguy]

OK, I'm with you so far. How does that integrate with the PD4045 power center that also charges the battery?

[Alex Adams]

Originally Posted by kombiguy

OK, I'm with you so far. How does that integrate with the PD4045 power center that also charges the battery?

You have a separate connection for the solar charge controller to the battery and one for the PD4045. Both should be able to charge the battery at the same time.

[kombiguy]

Excellent! Thanks! That'll make my life a lot easier!

[Mike Meyer]

Originally Posted by Alex Adams

You have a separate connection for the solar charge controller to the battery and one for the PD4045. Both should be able to charge the battery at the same time.

Don’t think that the PD 4045 will completely charge Lithium Iron phosphate batteries doesn’t have the special voltage output to top them off

[gordon2]

Originally Posted by Mike Meyer

Don’t think that the PD 4045 will completely charge Lithium Iron phosphate batteries doesn’t have the special voltage output to top them off

You don't need to top them off!

So.. this is a very involved subject, but the point I was making is that many existing chargers and converters will charge a LifePo4 but not fully charge them. Lead acid batteries live the longest if they are kept fully charged in storage and not discharged more than needed and not less than 50% for the most part. So topping them off is good. Yet LifePo4 batteries live the longest if stored at about 50% charge, and used from about 10-20 % charge at the low end to 80% at the high end. So topping them off all the time might actually shorten their life. Of course for people over about 60 years of age.. the difference in LifePo5 life span in those cases is roughly between the same to double. So if you are older then 60-65, then buying a special converter / charger might mean the difference between leaving the LifePo4 battery in your will for your heirs or not

[Motoboss]

Originally Posted by Mike Meyer

Don’t think that the PD 4045 will completely charge Lithium Iron phosphate batteries doesn’t have the special voltage output to top them off

Yes I believe it does. It should have a changeable pendant just for Li batteries. I recently purchased a PD4635 VL, the “V” denotes and “L” denotes Lithium. Not 100% positive about the PD4045 model but it “should” have the same VL designation.

But as @gordon2 posted not necessary…….

From the Progressive Dynamics website

“ PD4000 Series Features

Switch selects between Lead Acid and Lithium Batteries.

Compact & lightweight.

Reverse battery protection with easy to replace fuses.

Electronic current limiting.

High and low AC input protection.

Intelligent, variable speed, cooling fan.

Automatic thermal protection.

Front access to large wiring compartment.

Snap-lock cover stays shut while traveling – opens with a touch.

Attractive lightweight panel design made from black impact-resistant high temperature polymers.

Covered by one or more of the following U.S. Patents: 7,782,002 and RE39,461.”

[jwcolby123]

Originally Posted by mary and bob

The original solar panel had a very small output as it was only designed to maintain the battery when the trailers sat on the rental lots. It had a controller that was attached to the battery box. Best to toss it and maybe use the original mounts for a good modern panel.

Just permanently attach it to the battery!