Switching To Lithium in Camper???

[Rbertalotto]

I'm replacing two 12V / 110aH AGM batteries with two 12V / 100aH Lithium batteries. I have a Progressive Dynamics 4 stage converter / charger in the camper that I installed a couple years ago.
I sent an email to PD for instructions on how to set this converter charger to lithium. They said to move a jumper wire and the charger will now "constantly output 14.6 volts"......Will this be bad for Lithium batteries. Is there not some type of multiple stages of charge for Li batteries?

Thanks in advance for your help!

 

[sunshine_eggo]

I'm replacing two 12V / 110aH AGM batteries with two 12V / 100aH Lithium batteries. I have a Progressive Dynamics 4 stage converter / charger in the camper that I installed a couple years ago.
I sent an email to PD for instructions on how to set this converter charger to lithium. They said to move a jumper wire and the charger will now "constantly output 14.6 volts"......Will this be bad for Lithium batteries. Is there not some type of multiple stages of charge for Li batteries?

Thanks in advance for your help!

Yes.

Yes.


Your PD do this?
Boost: 14.4-14.6
Absorption: 13.8
Float: 13.2
4th stage? Repeat above every X hours?

The default 4 stage is better than 14.6V constant by a good measure.

 

[Rbertalotto]

The Progressive Dynamics unit I have is the PD4655V...55amp output

Inteli-Power 4600 Series models can recharge the battery to 90% in 3-6 hours using our patented Charge Wizard technology:

• BOOST Mode 14.4 Volts – Rapidly brings RV battery up to 90% of full charge.
• NORMAL Mode 13.6 Volts – Safely completes the charge.
• STORAGE Mode 13.2 Volts – Maintains charge with minimal gassing or water loss.
• EQUALIZATION Mode 14.4 Volts – Every 21 hours for a period of 15 minutes prevents battery stratification
  & sulfation – the leading cause of battery failure.

 

[Rbertalotto]

I just read this in the owners manual:

- LI models DO NOT have Charge Wizard functionality -

It appears PD offers a "LI" version....

CAUTION: The 4600LI series converter/chargers are designed to recharge lithium iron phosphate (LiFePO4) batteries only. DO NOT USE TO RECHARGE LEAD/ACID BATTERIES!

BUT...It appears their LI products are still single stage:

The PD4655LIV Lithium Converter offers a single stage charging profile that output a constant 14.6v designed to keep your Lithium Battery Fully Charged.

Wouldn't the batteries BMS compensate for this?

 

[sunshine_eggo]

The Progressive Dynamics unit I have is the PD4655V...55amp output

Inteli-Power 4600 Series models can recharge the battery to 90% in 3-6 hours using our patented Charge Wizard technology:

• BOOST Mode 14.4 Volts – Rapidly brings RV battery up to 90% of full charge.
• NORMAL Mode 13.6 Volts – Safely completes the charge.
• STORAGE Mode 13.2 Volts – Maintains charge with minimal gassing or water loss.
• EQUALIZATION Mode 14.4 Volts – Every 21 hours for a period of 15 minutes prevents battery stratification
  & sulfation – the leading cause of battery failure.

This is actually a fine charger profile. 13.6V is a great absorption/float voltage that will get you to 95%+ capacity if the 14.4V didn't already get you there. The 13.2V will allow a little bleed down of the battery.

The "Equalization" charge is not needed and not beneficial, but 15 minutes isn't going to hurt anything. Technically, the battery will be "micro-cycling," and it might have a measurable impact on service life, but this option is WAY better than 14.6V constant voltage.

IMHO, MOST "Li" converters are at best a poor implementation and don't offer any added value that justifies their cost.

 

[Rbertalotto]

Thank You!.......

 

[HRTKD]

IMHO, MOST "Li" converters are at best a poor implementation and don't offer any added value that justifies their cost.

This is true. I have an IOTA Engineering DLS-55 with the IQ-LiFePO4 module. I'm not impressed. It's rarely used as I'm not often connected to shore power. I have the converter on a separate circuit breaker so I can isolate it from the rest of the system and turn it off.

Fortunately, I'm replacing the converter with a Victron Multiplus inverter/charger that is programmable.

 

[K8MEJ]

It's possible that his batteries are going to be located quite some distance away from his 14.6v converter, and RV manufacturers don't use the best wiring. So, with the voltage drop, he's likely to be in the low 14ish volts constant voltage at the batteries. If that's the case, then it's not so bad. Not ideal, but not so bad.

 

[Patricktxfl]

Yes.

Yes.


Your PD do this?
Boost: 14.4-14.6
Absorption: 13.8
Float: 13.2
4th stage? Repeat above every X hours?

The default 4 stage is better than 14.6V constant by a good measure.

I know this is old and your assumption is how it reads, however the dynamic in this is the lithium is about 1v higher. That means if lithium is at 50% SOC the logic of wet cell charging puts it in float at low amperage. This would be fine if plugging in overnight, but doesn't support or leverage fast charge that you want if using generator power.

 

[Patricktxfl]

It's possible that his batteries are going to be located quite some distance away from his 14.6v converter, and RV manufacturers don't use the best wiring. So, with the voltage drop, he's likely to be in the low 14ish volts constant voltage at the batteries. If that's the case, then it's not so bad. Not ideal, but not so bad.

I can agree to your wiring statement. I ran into this issue with 20+ feet of 10 awg between converter and battery. That means day one they installed a 45 amp charger that had wire resistance to between 15 - 20 amps. Not a big deal if your charging daily with light draw down so smart charge is quickly in float. Its a big deal if on generator and doubling your charge time on lithium.

 

[triplethreat]

I just went through this a few weeks ago, with the factory wiring, factory battery disconnect, auto reset breaker, and the end result was a .6 to .7 volt drip from the charger to the actual battery. I use a Mean Well NPB-750-12 converter/charger and have it set on FLA and 3 stage charging. The results of replacing the OEM wiring, battery disconnect, breaker, and shortening the route from the charger to the battery resulted in a .1 volt drop instead of .6 or .7 drop. I am using 2 AWG welding cable, a new Blue Seas battery disconnect, a Bussman breaker, and the reroute made the path from the charger to the battery about 50% shorter than OEM....plus it went from 6 AWG to 2 AWG

Having the charger on the 3 stage and FLA provides in my opinion, a great voltage setup for the LFP battery. 14.2V boost, 13.4 volts for float and by utilizing the 3 stage instead of 2 stage, at the end of charging, the charger stays on and serves as a 13.2V converter for the electrical stuff....lighting, control power for water heater, etc, etc.

 

[HRTKD]

I know this is old and your assumption is how it reads, however the dynamic in this is the lithium is about 1v higher. That means if lithium is at 50% SOC the logic of wet cell charging puts it in float at low amperage. This would be fine if plugging in overnight, but doesn't support or leverage fast charge that you want if using generator power.

This gets into what is safe versus what is optimal. It can be tough to know which you're getting with some equipment out there. A programmable device can be both, but the user has to be knowledgeable enough to know the difference as well as how to apply the change. When friends ask me for recommendations, I have to asses if they're smart enough to program a device without blowing things up. If they don't pass that test, there's no way I'll recommend anything but a non-programmable safe device.

 

[Patricktxfl]

I just went through this a few weeks ago, with the factory wiring, factory battery disconnect, auto reset breaker, and the end result was a .6 to .7 volt drip from the charger to the actual battery. I use a Mean Well NPB-750-12 converter/charger and have it set on FLA and 3 stage charging. The results of replacing the OEM wiring, battery disconnect, breaker, and shortening the route from the charger to the battery resulted in a .1 volt drop instead of .6 or .7 drop. I am using 2 AWG welding cable, a new Blue Seas battery disconnect, a Bussman breaker, and the reroute made the path from the charger to the battery about 50% shorter than OEM....plus it went from 6 AWG to 2 AWG

Having the charger on the 3 stage and FLA provides in my opinion, a great voltage setup for the LFP battery. 14.2V boost, 13.4 volts for float and by utilizing the 3 stage instead of 2 stage, at the end of charging, the charger stays on and serves as a 13.2V converter for the electrical stuff....lighting, control power for water heater, etc, etc.

Maybe your brand charger logic is different. Progressive Dynamics logic measures the higher lithium voltage and using wet cell logic the charger quickly goes to float at low current. If you have good monitoring like shunt, try running battery to about 50% and check charging amps every 10 - 15 minutes. Mine started high but quickly went to float which is okay for overnight shore, but not good for generator charging.

 

[sunshine_eggo]

Maybe your brand charger logic is different. Progressive Dynamics logic measures the higher lithium voltage and using wet cell logic the charger quickly goes to float at low current. If you have good monitoring like shunt, try running battery to about 50% and check charging amps every 10 - 15 minutes. Mine started high but quickly went to float which is okay for overnight shore, but not good for generator charging.

the issue with 99% of converter performance, Lithium or not, is crap wiring.

 

[Patricktxfl]

This gets into what is safe versus what is optimal. It can be tough to know which you're getting with some equipment out there. A programmable device can be both, but the user has to be knowledgeable enough to know the difference as well as how to apply the change. When friends ask me for recommendations, I have to asses if they're smart enough to program a device without blowing things up. If they don't pass that test, there's no way I'll recommend anything but a non-programmable safe device.

Yea I didn't want to make a more complicated change then plug and play upgrade to converter. 45 amp charger against a single 100ah lithium battery gives quick enough charge on gen.

No big appliances, start gen for that.

We seldom camp on shore power, so 100 watt solar usually does decent job of charging. Then we start up gen occasionally, so I want to leverage all charging speed possible. If I can achieve near 45 amp charge its a good match for 50 amp max suggested for battery, and even 15 minutes of gen adds significant power.

 

[triplethreat]

Maybe your brand charger logic is different. Progressive Dynamics logic measures the higher lithium voltage and using wet cell logic the charger quickly goes to float at low current. If you have good monitoring like shunt, try running battery to about 50% and check charging amps every 10 - 15 minutes. Mine started high but quickly went to float which is okay for overnight shore, but not good for generator charging.

I had discharged my 302AH LFP battery down to ~44% SOC, as per the Victron 712. I keep a 200W, 12VDC heating element handy for discharging it since I don't have an inverter to drain it down, and no reason to fire up the 12VDC fridge when I can discharge at a higher rate with the heater. So once it was down to around 44% SOC, I turned the Mean Well on and let it rip. I basically had nothing else on in the camper, as it was at home and we were not camping in it. It ramped up to 40 to 41 amps (the Mean Well 750 max current is 43 amps) and stayed there until the battery voltage reached the boost voltage...14.2V. Once that happened, the voltage stays there and the current starts dropping off until it reaches the 10% mark of the charger rated current, which is 43 amps....so right around 4.3 amps. At that point, it will switch to float voltage, which is 13.4V and the light on the charger will turn green, indicating that the battery is charged. I have no desire to run my LFP battery all the way up to the 14.6V and that is where the LFP setting on the charger would take it. I like the 14.2/13.4 numbers a whole lot better, as it will be less stressful on the battery and hopefully extend the length of service time for me.

Getting all the components that are inline between the charger and battery to a very small voltage drop while pulling the charging current, was key to being able to make those settings work successfully.

 

[Jbarnes1719]

Why not just install a dc to dc charger like the victron orion in between your factory converter/charger and lifepo batteries?

 

[Rbertalotto]

Here is a quick Update on my Li conversion. Camped 42 days this past spring/summer since the installation. I could not be any more pleased! Previous system with two 110aH AGM batteries, I'd discharge to 70% by the morning light. It would take until around 3pm with very good sun to get back to 100%. And at 70% SOC, the voltage would be 12.4v +/-......With 200aH of Li, and at 70% discharge until first light, with good sun the batteries are back up to 100% by noon! Even in poor light they always returned to 100% by late afternoon, where the AGMs would not. (420w (3x140w) of 12V / parellel solar on flat roof...In New England)...And the bonus of the voltage staying at 13.5-13.2V throughout the days allows my 12V TVs and my laptop to operate better. Then add the reduction of about 100 pounds from my tounge weight.......switching to Li was a no brainer!

 

[12VoltInstalls]

with two 110aH AGM batteries, I'd discharge to 70% by the morning light. It would take until around 3pm with very good sun to get back to 100%. And at 70% SOC, the voltage would be 12.4v +/-......With 200aH of Li, and at 70% discharge until first light, with good sun the batteries are back up to 100% by noon!

Something doesn’t add up for me.

Your two AGMs were how old?
70% state of charge with 100Ah of AGM vs 70% with 200Ah on LiFePo would mean you are depleting double the Ah capacity at twice the rate of discharge. This makes little sense, apples to apples.

I’m trying to understand this.

 

[Rbertalotto]

“Your two AGMs were how old”… seven years old