Switching to Lithium Batteries

[Sandridge4]

Hello-I am currently considering switching from SLA to Lithium batteries and have read as many applicable threads here as well as other web sources. The reason for considering the switch is being able to run the fridge while going down the road, in the last year of full time living we have only had 3 nights without shore power and we have a portable generator if batteries needed topping off. My rig currently has 600 watts of solar panels a 30 amp MPPT controller capable of charging lithium and a converter that is also lithium capable.

Is a DC-DC controller necessary for my TV connection? If not needed what are the benefits of having the DC-DC?

What else am I not considering or will need to purchase for a successful lithium conversion?

[ncitro]

Sandridge4 I ran my setup without a DC to DC for about a year with no issues. That is not to say you will not, just my experience. It offers two things, one it isolates the trailer from the truck electrically, theoretically eliminating the risk of overloading the factory wiring (since the lithium batteries are capable of taking so much charge current). I never experienced this issue, but some do worry about it. The second reason is you can raise the charging voltage, and increase the output current. In my case I run the Renogy 40A version, so I get my required charge voltage for lithium and more output (Ford diesel with dual alternators so plenty of power available). Basically I went from about 7 amps of charge from the factory 7 pin to 40 at the higher voltage lithium needs to get to 100%. I run my residential fridge, internet gear in the trailer, and sometimes my crock pot via my inverter, and always arrive at 100% SOC even if its raining and I am not getting any solar. I think its a great upgrade.

Be advised if you go with a larger DC to DC it does require upgraded wiring from the truck, there are a few posts from those of us that have done it. There are also some posts from a few that have used the factory wiring to use a 20A DC to DC.

[howson]

Hello-I am currently considering switching from SLA to Lithium batteries and have read as many applicable threads here as well as other web sources. The reason for considering the switch is being able to run the fridge while going down the road, in the last year of full time living we have only had 3 nights without shore power and we have a portable generator if batteries needed topping off. My rig currently has 600 watts of solar panels a 30 amp MPPT controller capable of charging lithium and a converter that is also lithium capable.

Is a DC-DC controller necessary for my TV connection? If not needed what are the benefits of having the DC-DC?

What else am I not considering or will need to purchase for a successful lithium conversion?

My .02 is to start by getting two 100ah lithium batteries or one 200aH (depending on where you're going to mount it and how much space you have). That much battery capacity will effectively quadruple the amount of power available for use off-grid. Learn to live with the "larger gas tank" (the 200ah of batteries) and ensure you're satisfied with the charger and current solar performance. In other words, how long it takes those two components to "refill the gas tank". If you find that you need more x (we don't know what that is right now), that information will inform the next best upgrade.

Howard

[Sandridge4]

howson ncitro Well the day for the conversion finally came! I ended up with 2 LiTime 100AH batteries and also decided to change the converter to a Powermax…. Since I was spending money I also added a Victron Smart Shunt and Victron 100/50 MPPT charge controller. Now for the questions.
1. on the shunt I have seen several people say many of the settings need to be changed for lithium? I don’t see any setting recommendations for lifepo4 on the Victron website.
2. Other than the pre programmed charge controller settings is there anything else that should be changed for the charge controller? Again Victron says the lithium settings are pre programmed or can be customized but nothing indicating what they should actually be?

Thanks for any advice!!

[Kathy&Jim_Imagine]

Best bet is to contact the battery mfg. and find out if they have recommended settings for the Victron (or other brands) gear. I use Lion UT1300's and contacted Lion for that info. They were happy to share their recommended settings for all my Victron gear. I just had to tell them what components and model numbers I had and they e-mailedt over the info.

[howson]

howson ncitro Well the day for the conversion finally came! I ended up with 2 LiTime 100AH batteries and also decided to change the converter to a Powermax…. Since I was spending money I also added a Victron Smart Shunt and Victron 100/50 MPPT charge controller. Now for the questions.
1. on the shunt I have seen several people say many of the settings need to be changed for lithium? I don’t see any setting recommendations for lifepo4 on the Victron website.
2. Other than the pre programmed charge controller settings is there anything else that should be changed for the charge controller? Again Victron says the lithium settings are pre programmed or can be customized but nothing indicating what they should actually be?

Thanks for any advice!!

TucsonJim -- didn't you just buy LiTime batteries, too? (I may be mistaken.) If so, what settings are you going to use with your Victron gear?

Scott ( Sandridge4 ) -- if there's any question about the PowerMax, timelinex has one, too.

Howard

[timelinex]

TucsonJim -- didn't you just buy LiTime batteries, too? (I may be mistaken.) If so, what settings are you going to use with your Victron gear?

Scott ( Sandridge4 ) -- if there's any question about the PowerMax, timelinex has one, too.

Howard

I had the 60a pm4 and that worked great till I replaced it with a 100a. I haven't put the 100a thru its paces but so far it works. Both of then ran on CC, so i cant comment on using them in the 4 stag setting.

[TucsonJim]

TucsonJim -- didn't you just buy LiTime batteries, too? (I may be mistaken.) If so, what settings are you going to use with your Victron gear?


Howard

I did purchase four LiTime batteries. Each battery came with excellent documentation in the box that defines the charging and monitoring criteria. It was very well written and comprehensive.

Jim

[howson]

Each battery came with excellent documentation in the box that defines the charging and monitoring criteria.

Do you have the ability to scan and post the information, Jim?

[TucsonJim]

This link has the charging and usage information for all their batteries.

https://www.litime.com/pages/compare-batteries#0

Jim

[Sandridge4]

I had the 60a pm4 and that worked great till I replaced it with a 100a. I haven't put the 100a thru its paces but so far it works. Both of then ran on CC, so i cant comment on using them in the 4 stag setting.

I am running cc, have emailed them as the fan seems to run about every 3 minutes for 30-45 seconds.

[ncitro]

I am running cc, have emailed them as the fan seems to run about every 3 minutes for 30-45 seconds.

Just a note for your and timelinex if by CC you mean constant current, you (hopefully) actually mean constant voltage. The violtage should be fixed and the current should vary as the state of charge increases.

[timelinex]

Doh! Yes, I mean constant voltage!

[Sandridge4]

Sandridge4 I ran my setup without a DC to DC for about a year with no issues. That is not to say you will not, just my experience. It offers two things, one it isolates the trailer from the truck electrically, theoretically eliminating the risk of overloading the factory wiring (since the lithium batteries are capable of taking so much charge current). I never experienced this issue, but some do worry about it. The second reason is you can raise the charging voltage, and increase the output current. In my case I run the Renogy 40A version, so I get my required charge voltage for lithium and more output (Ford diesel with dual alternators so plenty of power available). Basically I went from about 7 amps of charge from the factory 7 pin to 40 at the higher voltage lithium needs to get to 100%. I run my residential fridge, internet gear in the trailer, and sometimes my crock pot via my inverter, and always arrive at 100% SOC even if its raining and I am not getting any solar. I think its a great upgrade.

Be advised if you go with a larger DC to DC it does require upgraded wiring from the truck, there are a few posts from those of us that have done it. There are also some posts from a few that have used the factory wiring to use a 20A DC to DC.

ncitro did you document your installation on the forum? I have found several others but am interested in yours since we have similar TV’s and am now thinking the 40A DC to DC will be my next upgrade. Want to start planning and building a shopping list!

[ncitro]

ncitro did you document your installation on the forum? I have found several others but am interested in yours since we have similar TV’s and am now thinking the 40A DC to DC will be my next upgrade. Want to start planning and building a shopping list!

I did not do my own write up, but I did my install around the same time Howard did his, and posted a lot about the process in his thread.

https://gdrvowners.com/forum/operati...e-battle-borns