Going Lithium

[tlmgcamp1]

4 year old stock FLA in garage all winter on Battery minder. Noticed that the wood it sat on was wet. Moved it to a dry spot and sure enough, a puddle formed. So I am going to Lithium a little sooner than I planned. Can anyone recommend a source of detailed installation information? My converter will.do lithium but not the solar controller. I also believe that I need a dc-dc charger to protect the TV from the high amperage of a discharged lithium.

 

[Isaac-1]

The biggest issue of switching to LiFePo4 batteries is to unlearn all those Lead Acid battery things that you assumed applied to all batteries, such as the need to float charge them and keep them fully charged while in storage, as the opposite is best for LiFePo4

 

[tlmgcamp1]

The biggest issue of switching to LiFePo4 batteries is to unlearn all those Lead Acid battery things that you assumed applied to all batteries, such as the need to float charge them and keep them fully charged while in storage, as the opposite is best for LiFePo4

I am planning a switch to be able to turn off the solar panels to keep the batteries from charging when not in use.

 

[DonTom]

? My converter will.do lithium but not the solar controller. I also believe that I need a dc-dc charger to protect the TV from the high amperage of a discharged lithium.

Solar controllers are cheap these days and easy to replace with a controller that can do lith as well as LA.

The ~1-volt higher voltage (not the amperage, which means only the capacity on a battery) from the lith batteries will not hurt your TV. I assume its running from a 120 VAC inverter. They normally can even accept the close to ~15 VDC input while the lith battery is charging.

My TV in my Y2K RV is fed with my 300-AH lith to an inverter to the TV and it is happy even while it is charging at close to 15 VDC.

But to be sure, if possible, check your inverter input voltage range. Some will go into an alarm and shut off right at 15 volts. You will most likely be just below that anyway, at around 14.6 VDC while the battery is being charged via your lith converter. Even less if not a lith converter.

-Don- Auburn, CA

 

[Lou Schneider]

How many lithium batteries are you planning to install? In the real world, if you're only putting in one or two 100 a/h batteries the series resistance of the long wire coming from the tow vehicle's alternator will limit the initial charge rate to a safe value. It only drops the voltage a volt or so at the battery end when the battery is at a low state of charge but that's enough to control the current.

DC to DC chargers are only needed to limit the charging current to a safe value if you're installing a large battery bank or (ironically) if you want more charging current than the stock wire can deliver. The stock charging profile of an automotive alternator (starting at 14.5 volts when cold to deliver a quick fill-up to the starting battery, then ramping down to 13.5 volts as the alternator warms up) is actually a pretty good match to a lithium battery as long as there's something to limit the initial surge into a discharged battery. Like I said, a long charging wire will do that.

 

[Isaac-1]

Just to add to what Lou said, a DC-DC Charger can also be important in a motorhome where the house batteries may be located closer in wire feet to the alternator.

 

[Lou Schneider]

Just to add to what Lou said, a DC-DC Charger can also be important in a motorhome where the house batteries may be located closer in wire feet to the alternator.

200 a/h of lithium in my Safari Trek under the entry step (about 20 wire-feet of 8 gauge cable from the alternator) drew a maximum of 50 amps from the alternator when heavily discharged, making a DC-DC charger unnecessary. More batteries than that would require one to limit the charging draw from the alternator, though.

 

[Isaac-1]

True, where as I have 420AH in my Trek which I relocated to under the kitchen sink, and do have a DC-DC charger, though I am not sure it is required, I feel better about having one.

 

[tlmgcamp1]

Solar controllers are cheap these days and easy to replace with a controller that can do lith as well as LA.

The ~1-volt higher voltage (not the amperage, which means only the capacity on a battery) from the lith batteries will not hurt your TV. I assume its running from a 120 VAC inverter. They normally can even accept the close to ~15 VDC input while the lith battery is charging.

My TV in my Y2K RV is fed with my 300-AH lith to an inverter to the TV and it is happy even while it is charging at close to 15 VDC.

But to be sure, if possible, check your inverter input voltage range. Some will go into an alarm and shut off right at 15 volts. You will most likely be just below that anyway, at around 14.6 VDC while the battery is being charged via your lith converter. Even less if not a lith converter.

-Don- Auburn, CA

There is no inverter.

 

[tlmgcamp1]

How many lithium batteries are you planning to install? In the real world, if you're only putting in one or two 100 a/h batteries the series resistance of the long wire coming from the tow vehicle's alternator will limit the initial charge rate to a safe value. It only drops the voltage a volt or so at the battery end when the battery is at a low state of charge but that's enough to control the current.

DC to DC chargers are only needed to limit the charging current to a safe value if you're installing a large battery bank or (ironically) if you want more charging current than the stock wire can deliver. The stock charging profile of an automotive alternator (starting at 14.5 volts when cold to deliver a quick fill-up to the starting battery, then ramping down to 13.5 volts as the alternator warms up) is actually a pretty good match to a lithium battery as long as there's something to limit the initial surge into a discharged battery. Like I said, a long charging wire will do that.

Only looking at 1-100Ah lithium. I have heard the idea of the TV wire controlling power. Honestly, that sounds a little sketchy as. My thought is that wire is not generally intended to be a device for controlling. Almost like saying "we know we are at capacity when the tires blow". Maybe I am not fully understanding the concept

 

[tlmgcamp1]

200 a/h of lithium in my Safari Trek under the entry step (about 20 wire-feet of 8 gauge cable from the alternator) drew a maximum of 50 amps from the alternator when heavily discharged, making a DC-DC charger unnecessary. More batteries than that would require one to limit the charging draw from the alternator, though.

My last TV (need to check this one) had a 30 amp fuse on the hot lead to the trailer. Using your scenario, my single 100Ah should peak around 25 amps. That doesn't leave me much. I need to check that fuse, trying to control flow to battery to 1/2 of that fusr

 

[Mark_K5LXP]

I have heard the idea of the TV wire controlling power. Honestly, that sounds a little sketchy as. My thought is that wire is not generally intended to be a device for controlling.

Wire is a stable component. If it's operated within it's ratings it will do the same thing the same way indefinitely.

Wonder and guess or measure and know. Put in your battery, set everything up the way you'll typically use it. Run the battery dead, and see what current you're pulling from the TV. The weak link is the trailer-TV connector. Some are only rated for 10 or 15A. None of this is guesswork - you can measure the TV's voltage drop, trailer's voltage drop and actual current. If you discover things are out of bounds then from there a mitigation plan decided. You might discover things are just fine.

Mark B.
Albuquerque, NM

 

[Gary RV_Wizard]

The ~1-volt higher voltage (not the amperage, which means only the capacity on a battery) from the lith batteries will not hurt your TV. I assume its running from a 120 VAC inverter. They normally can even accept the close to ~15 VDC input while the lith battery is charging.

My TV in my Y2K RV is fed with my 300-AH lith to an inverter to the TV and it is happy even while it is charging at close to 15 VDC.

I believe that "TV" in the OP's context meant "Tow Vehicle" rather than "TeleVision". So yes, a discharged lith battery can put a severe load on the TV's alternator.

 

[tlmgcamp1]

I believe that "TV" in the OP's context meant "Tow Vehicle" rather than "TeleVision". So yes, a discharged lith battery can put a severe load on the TV's alternator.

Yes...Tow Vehicle. The TV fuse for the trailer is 30 amp, as is my converter. Aside from charging the battery, I believe the only other big draw is brakes. I have a 120v/LP fridge. If I could limit the charge to the lithium to 10 or 15 amps, I think that is comfortable

 

[tlmgcamp1]

So any suggestions on brands for the solar controller?

 

[zulutron]

So any suggestions on brands for the solar controller?

Victron. How much solar do you plan to install?

 

[IBTripping]

For a 12 volt 100 amp lithium battery, you won't need an expensive solar charge controller. You might consider an MPPT rather than a PWM controller. But, if money is an issue, you can get a PWM Renogy 30 amp controller for about $30 on Amazon which will work fine. Some of the brand names that are popular include Victron, LiTime, BougeRV, and Renogy. Amazon has a Victron MPPT15 amp controller for about $60. There are a bunch of off brand models which may work fine and cost much less. I purchased an inexpensive controller to begin with as I was learning to set up a solar system. Works great. But, don't know how long it will last. I'll use it as a backup controller.

Here's some links to inexpensive brand name controllers:

https://www.amazon.com/Victron-SmartSolar-Charge-Controller-Bluetooth/dp/B075NQQRPD

https://www.amazon.com/Renogy-12V-Solar-Charge-Controller/dp/B0DXF37VLR

https://www.amazon.com/Controller-Display-LiFePO4-Lithium-Battery/dp/B0CTJM9XBZ

 

[zulutron]

For a 12 volt 100 amp lithium battery, you won't need an expensive solar charge controller.

OP needs to figure out how much wattage he's putting on his roof before buying a charge controller.

FYI -- all your Amazon links can be shortened by deleting everything from "ref=" on, like so:

Amazon.com: Victron Energy SmartSolar MPPT Solar Charge Controller (Bluetooth) - Charge Controllers for Solar Panels - 75V, 15 amp, 12/24-Volt : Patio, Lawn & Garden

Buy Victron Energy SmartSolar MPPT Solar Charge Controller (Bluetooth) - Charge Controllers for Solar Panels - 75V, 15 amp, 12/24-Volt: Energy Controllers - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

 

[tlmgcamp1]

OP needs to figure out how much wattage he's putting on his roof before buying a charge controller.

FYI -- all your Amazon links can be shortened by deleting everything from "ref=" on, like so:

Amazon.com: Victron Energy SmartSolar MPPT Solar Charge Controller (Bluetooth) - Charge Controllers for Solar Panels - 75V, 15 amp, 12/24-Volt : Patio, Lawn & Garden

Buy Victron Energy SmartSolar MPPT Solar Charge Controller (Bluetooth) - Charge Controllers for Solar Panels - 75V, 15 amp, 12/24-Volt: Energy Controllers - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

I have 100w now. We don't boondock but would like to have the option of a day or two in an unforseen situation. There may be another 100w in the future but that is probably a 50/50 possibility. Trailer itself is 30amp

 

[tlmgcamp1]

For a 12 volt 100 amp lithium battery, you won't need an expensive solar charge controller. You might consider an MPPT rather than a PWM controller. But, if money is an issue, you can get a PWM Renogy 30 amp controller for about $30 on Amazon which will work fine. Some of the brand names that are popular include Victron, LiTime, BougeRV, and Renogy. Amazon has a Victron MPPT15 amp controller for about $60. There are a bunch of off brand models which may work fine and cost much less. I purchased an inexpensive controller to begin with as I was learning to set up a solar system. Works great. But, don't know how long it will last. I'll use it as a backup controller.

Here's some links to inexpensive brand name controllers:

Amazon.com

Amazon.com

Amazon.com

What is the difference between PWM and MPPT?