diy solar

diy solar

Using an RV Converter as a Charger

Knightoj

New Member
Joined
Nov 9, 2020
Messages
1
Hello. I'm an RV owner and still in the process of learning about Lithium batteries. I have a Progressive Dynamics converter and here is a quote from one of their FAQs in response to question of using the lead/acid charger to charge a lithium battery:

"Yes, if you are willing to live with an expensive battery that is only partially charged. The Normal Output voltage of the PD9200, PD4000 and PD4500 Series voltage provides only 13.6-volts and a full charge voltage for Lithium needs to be 14.4 – 14.6 Volts. The PD9200, PD4000 & PD4500 Series Charge Wizard will initially jump to 14.4-volts in the Boost Mode when first connected to 120 VAC power and will remain there until the battery voltage reaches 13.8-Volts, then automatically drops down to the Normal Mode of 13.6-Volts. The faster charge rate of Lithium means that in the Boost Mode it will reach this 13.8-Volt point after only a few minutes of recharging and then the charging current will drop to ZERO AMPS and will not add any additional charge to your Lithium Battery. This lower charge state will not damage your battery, but will eliminate most of the advantages you paid for."

From one of Will's videos he was saying to increase the life of lithium batteries keep them charged between 10/20 to 80/90 percent. So if I use the PD converter to charge to 13.6v and be careful that I don't discharge below12% wouldn't the PD charger work?
 
FWIW, I've never seen an RV converter that does an equalization cycle. Iota, Progressive Dynamics, Powermax, etc. Not a single one offers that. Iota MIGHT have an IQ4 module that has an equalization function, but that's an add-on.
 
I have a Powermax pm3 55, cant I just turn the high pot down inside of my converter and use it to charge my Battleborn?
 
I have a Powermax pm3 55, cant I just turn the high pot down inside of my converter and use it to charge my Battleborn?

Welcome to the forum. Set your unloaded voltage to 14.4V, and you're good to go. Leave it in 3 phase mode. Don't use constant voltage mode.
 
FWIW, I've never seen an RV converter that does an equalization cycle. Iota, Progressive Dynamics, Powermax, etc. Not a single one offers that. Iota MIGHT have an IQ4 module that has an equalization function, but that's an add-on.
my PD4600 has an equalization mode
 
my PD4600 has an equalization mode

No it doesn't. It reverts to boost mode once every 21 hours for 15 minutes. They call it equalization, but it isn't. It's technically a forced re-bulk.

From:



1609946783989.png
For cyclic applications, this isn't a concern, but for an RV on long-term shore power, this isn't optimal for LFP. It's not likely to do any harm because it's going to hit 14.4V almost instantly and the current will taper to nothing. The Storage mode at 13.2V might actually pull down the SoC of the LFP slightly if it's in use, so re-bulk could be a non-issue. Due to the uncertainty, I would likely not choose to use this in an LFP application. If this RV is not in-use, I would disable the converter.

This behavior is essentially the same as a Powermaxx PM4. The PM4 is adjustable, so the impact of the re-bulk can be eliminated.
 
No it doesn't. It reverts to boost mode once every 21 hours for 15 minutes. They call it equalization, but it isn't. It's technically a forced re-bulk.

From:



View attachment 32346
For cyclic applications, this isn't a concern, but for an RV on long-term shore power, this isn't optimal for LFP. It's not likely to do any harm because it's going to hit 14.4V almost instantly and the current will taper to nothing. The Storage mode at 13.2V might actually pull down the SoC of the LFP slightly if it's in use, so re-bulk could be a non-issue. Due to the uncertainty, I would likely not choose to use this in an LFP application. If this RV is not in-use, I would disable the converter.

This behavior is essentially the same as a Powermaxx PM4. The PM4 is adjustable, so the impact of the re-bulk can be eliminated.


hello again Snoobler, you seem to be a wizard at this stuff

I am curious about a very similar questions, the manufacturer of my rig has advised me the stock charger is the following

Progressive Dynamics 45 amp converter. The model # is PD4045KA.

PD actually told me that there is a jumper i can adjust to allow the charger to work with lithium. Thoughts?
 
FWIW, I've never seen an RV converter that does an equalization cycle. Iota, Progressive Dynamics, Powermax, etc. Not a single one offers that. Iota MIGHT have an IQ4 module that has an equalization function, but that's an add-on.
Magnum does
 
hello again Snoobler, you seem to be a wizard at this stuff

I am curious about a very similar questions, the manufacturer of my rig has advised me the stock charger is the following

Progressive Dynamics 45 amp converter. The model # is PD4045KA.

PD actually told me that there is a jumper i can adjust to allow the charger to work with lithium. Thoughts?


Switch to operate in 14.6V constant voltage mode or 13.6V constant voltage mode with charge wizard enabled if installed.

14.6V would be bad. would only do for rapid charge and would want to disable the moment 14.6V is hit.

13.6V would be fine, it would just take about 6 hours to get 90-95% charged. Never 100%.

Charge Wizard:


Would behave as I described in post #8 above. Likely fine, but not optimal. Would charge it to a higher state of charge more quickly at 14.4V, top it off at 13.6V and then float at 13.2V. Ever 21? hours, repeat the run to 14.4V.

Magnum does

Link?
 

Switch to operate in 14.6V constant voltage mode or 13.6V constant voltage mode with charge wizard enabled if installed.

14.6V would be bad. would only do for rapid charge and would want to disable the moment 14.6V is hit.

13.6V would be fine, it would just take about 6 hours to get 90-95% charged. Never 100%.

Charge Wizard:


Would behave as I described in post #8 above. Likely fine, but not optimal. Would charge it to a higher state of charge more quickly at 14.4V, top it off at 13.6V and then float at 13.2V. Ever 21? hours, repeat the run to 14.4V.



Link?
Would you recommend that i buy something else more suitable for lithium? I want the right tools for the job ;)

edit: interesting bc PG told me literally , " this is what we would do at the factory to upgrade this unit to our new lithium compatible controller"
 
Last edited:
They're shoe-horning their existing technology into a new battery chemistry that needs little to no tweaking to act as a drop-in for lead-acid batteries.

What is your application?
  1. do you plan to cycle the batteries daily?
  2. do you plan to use it on shore power for extended periods?
  3. do you plan to keep it stored on shore power?
1 would benefit from the charge wizard as it would recharge the battery faster, but it would be ideal if it didn't have the "equalization" cycle every 21 hours.
2 and 3 would benefit from a constant 13.6V voltage.
If 3 involves absolutely no power use at all, it would be best to turn off the converter.

With LFP charging, you never want to exceed 14.6V in bulk (lower voltages work too) or float above 13.6V. It's that simple.
 
They're shoe-horning their existing technology into a new battery chemistry that needs little to no tweaking to act as a drop-in for lead-acid batteries.

What is your application?
  1. do you plan to cycle the batteries daily?
  2. do you plan to use it on shore power for extended periods?
  3. do you plan to keep it stored on shore power?
1 would benefit from the charge wizard as it would recharge the battery faster, but it would be ideal if it didn't have the "equalization" cycle every 21 hours.
2 and 3 would benefit from a constant 13.6V voltage.
If 3 involves absolutely no power use at all, it would be best to turn off the converter.

With LFP charging, you never want to exceed 14.6V in bulk (lower voltages work too) or float above 13.6V. It's that simple.
you know what funny? lol you said "its that simple" and i actually did not understand a word you said !!! LMAOOOO

jk i understood some

Ill be mostly boondocking and hardly ever connecting to shore power , maybe 15amps from driveways from time to time but no RV parks.

I will be full timing in my truck camper so yes i believe i will be cycling the batteries daily, although im not sure to what levels, i guess that depends on how much power /solar i produce/uce

I will not be on shore power for extended periods

I will not be storing the rig on shore power


relying almost completely on the solar so i wonder if that changes the thoughts on the stock Progressive dynamics charger
 

Switch to operate in 14.6V constant voltage mode or 13.6V constant voltage mode with charge wizard enabled if installed.

14.6V would be bad. would only do for rapid charge and would want to disable the moment 14.6V is hit.

13.6V would be fine, it would just take about 6 hours to get 90-95% charged. Never 100%.

Charge Wizard:


Would behave as I described in post #8 above. Likely fine, but not optimal. Would charge it to a higher state of charge more quickly at 14.4V, top it off at 13.6V and then float at 13.2V. Ever 21? hours, repeat the run to 14.4V.



Link?

Inverter Chargers | Magnum Dimensions - Magnum Energy

1610035668587.pngThat is the best i can do. All the really high end inverter chargers do that. You do a good job you have helped me a bunch. Look at the 3012 or the 2812 inverter charger. not just charger.
www.magnum-dimensions.com
 
They're shoe-horning their existing technology into a new battery chemistry that needs little to no tweaking to act as a drop-in for lead-acid batteries.

What is your application?
  1. do you plan to cycle the batteries daily?
  2. do you plan to use it on shore power for extended periods?
  3. do you plan to keep it stored on shore power?
1 would benefit from the charge wizard as it would recharge the battery faster, but it would be ideal if it didn't have the "equalization" cycle every 21 hours.
2 and 3 would benefit from a constant 13.6V voltage.
If 3 involves absolutely no power use at all, it would be best to turn off the converter.

With LFP charging, you never want to exceed 14.6V in bulk (lower voltages work too) or float above 13.6V. It's that simple.

Thank you for this info. I am working to switch my RV to LiPo this spring as I am looking to do more camping without shorepower but only for 2-3 days.
My situation/application will be primarily #2 and 3 above.

I assumed I would have to change out my converter anyway.
So I am thinking the Powermax converter that you can dial in the voltage to 13.6V that was mentioned above in posts #6 and 8.
 

Inverter Chargers | Magnum Dimensions - Magnum Energy

View attachment 32442That is the best i can do. All the really high end inverter chargers do that. You do a good job you have helped me a bunch. Look at the 3012 or the 2812 inverter charger. not just charger.
www.magnum-dimensions.com

Per the subject line "Using an RV Converter as a Charger" and my text you quoted, we're not talking about inverters. We're talking about converters - devices that only take AC and convert to DC for RV house battery charging.


Thank you for this info. I am working to switch my RV to LiPo this spring as I am looking to do more camping without shorepower but only for 2-3 days.
My situation/application will be primarily #2 and 3 above.

I assumed I would have to change out my converter anyway.
So I am thinking the Powermax converter that you can dial in the voltage to 13.6V that was mentioned above in posts #6 and 8.

Welcome to the forum.

LiPo is not LFP. It tends to refer to Lithium Polymer or "pouch" cells, which can be extremely dangerous. If you intend to do LiPo, I would urge you to go LFP.

As LFP are essentially drop-ins for many 12V lead-acid applications, your converter may be fine. What is it?
 
you know what funny? lol you said "its that simple" and i actually did not understand a word you said !!! LMAOOOO

jk i understood some

Ill be mostly boondocking and hardly ever connecting to shore power , maybe 15amps from driveways from time to time but no RV parks.

I will be full timing in my truck camper so yes i believe i will be cycling the batteries daily, although im not sure to what levels, i guess that depends on how much power /solar i produce/uce

I will not be on shore power for extended periods

I will not be storing the rig on shore power


relying almost completely on the solar so i wonder if that changes the thoughts on the stock Progressive dynamics charger

The unit you reference in 13.6V mode with a charge wizard module is fine.
 
Welcome to the forum.

LiPo is not LFP. It tends to refer to Lithium Polymer or "pouch" cells, which can be extremely dangerous. If you intend to do LiPo, I would urge you to go LFP.

As LFP are essentially drop-ins for many 12V lead-acid applications, your converter may be fine. What is it?

Good catch, moving to LiFePO4. Need to recalibrate my brain, always called them LiPo for the RC trucks. I will have to look up the converter model exactly to be sure.
 
Per the subject line "Using an RV Converter as a Charger" and my text you quoted, we're not talking about inverters. We're talking about converters - devices that only take AC and convert to DC for RV house battery charging.

Welcome to the forum.

LiPo is not LFP. It tends to refer to Lithium Polymer or "pouch" cells, which can be extremely dangerous. If you intend to do LiPo, I would urge you to go LFP.

As LFP are essentially drop-ins for many 12V lead-acid applications, your converter may be fine. What is it?
FB_IMG_1610071267680.jpg

WF 8955pec is the converter model.

From the website:
The WF-8955 model provides 55 Amps and a clean, constant 13.6 VDC nominal output, for reliable operation of electronics and appliances. Automatic three-stage charging extends the life of your battery with output voltage modes of 13.2 VDC range “float” mode, 13.6 VDC range “absorption” mode, and a 14.4 VDC range “bulk” charge mode.
 
Last edited:
Back
Top