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Progressive Dynamics Lithium battery Chargers.... or are they just Power Supplies?

ghostwriter66 said:
Just want to make sure that we are on the same sheet of paper with what i am saying - you don't have to agree - just don't misunderstand what i am saying ...

So here goes some rambling ...

We have 1000's of LIFEPO4 batteries operating where I work. Along with that we have probably some of the most recognized experts in the field of EE and Chemistry working for these major oil companies ... Almost all of the experts that I have read have agreed on 3 things.

1. The greatest threat to LIFEPO4 is the stress that it suffers when exposed to HEAT. HEAT is the #1 killer of LiFePO4.

2. Right after that - a second greatest threat is failure from stress when exposed to keeping a LiFePO4 at a high charge voltage.

3. Batteries should be stored for long periods of time with no more than 45% charge.

4. A LiFePO4 battery can be safely and routinely overcharged to 4.2 volts per cell, but at 4.25 there is a break down of the organic electrolytes that can never be recovered from.

For where I work - they tell us that keeping a LiFePO4 battery above 85°F is the start of the "not recommended" scale. As you can imagine I work in South Texas and it was 82 degrees yesterday in WINTER. In summer we will have heat of 120 daily ... so yes - while the engineers agree that anything after 85 there is a gradual ramp up to "REALLY BAD" (157), we do all we can to keep the battery temps as cool as we can ...

FOR US -- we never set our charge voltage higher than the 13.88 volts (3.47 V/per cell). 13.88 is our maximum charge voltage. This is NOT based on anything scientific. And each manufacture has their own recommendations -- This is based on 10 years of our guys using these batteries all over the world. And 100's of engineers running real-world numbers.

For the record - we charge our batteries to about 96% (13.88) and run them down to 10% - and we find that's the best number FOR US to maximize the storage capability of these batteries.

BUT BUT BUT with all of that said -- and if you put 5 EXPERTS in a room you get 7 opinions -- LFP is such a new technology that ppl - even the experts all sort of only agree on about 80% of the stuff out there ... it truly is a new technology that is getting better every day ...

I will tell you though - that there are allot of battery companies that sell LFPs - especially some of the largest US ones - that honestly are just spouting CRAP in order to sell their batteries. Their answers are vague at best and they never can back up their answers with empirical data except "well the CEO has a PHd in something or other" type stuff ... (yes this is a sore point for me)
Click to expand...
@ghostwriter66
Your point 1 (for the benefit of newbies),with articles i've read, would indicate heat from 20degC to 30degC actually helps lifepo4 perform better(so not all heat is bad) Maybe they should relabel it as 'All heat above 85degF is bad'.

Also if charging from a (solely) solarPV source at very low C rates with intermitant cloud cover, might it benefit from a higher input voltage, to get the ions moving faster ie could you set the SCC charge at a CV of say 4v/cell but terminate the charge on hitting 3.47v/cell? Would love to see any studies done of this? (The difference might be so minimal as to be not worth the risks involved or, if there is not much solar gains to be had, it might make the difference of 20% on low numbers?)
 
Excellent topic. I really enjoyed the presentation and I'm finding I have been learning a lot from your posts! I have a DC to DC charger and I don't trust it to turn off at goal voltage. Additionally, sometimes we are storing our batteries and don't want to charge them 100% SOC. I have found a cheap voltage sensitive relay module I am using to *TURN OFF CHARGING* at 95% SOC and 50% SOC. This *charger controller* on time 4:58 in the video is my solution to stopping charging before I reach BMS limits.
 
Solarfun4jim said:
@ghostwriter66

Also if charging from a (solely) solarPV source at very low C rates with intermitant cloud cover, might it benefit from a higher input voltage, to get the ions moving faster ie could you set the SCC charge at a CV of say 4v/cell but terminate the charge on hitting 3.47v/cell? Would love to see any studies done of this? (The difference might be so minimal as to be not worth the risks involved or, if there is not much solar gains to be had, it might make the difference of 20% on low numbers?)
Click to expand...

That does not add up. There is a constant current period of charging where the voltage on the charger will be under the target voltage. During this time, the voltage is limited to keep the current at the desired level (or at the max of the charger). Since the voltage is limited, it does not mater what the target voltage is, your not going to "get the ions moving faster". Once the battery starts getting close to full charge the voltage will start rising till it hits the target voltage (Lets say 3.47 volts). Up to this point it does not mater if the charger had been set to a higher voltage.... because that voltage has not yet happened due to the current limitation.

Once you hit your target voltage, you are proposing to stop the charging. That is OK but the batteries are not yet fully charged. To fully charge them, you must hold the voltage at the target voltage till the current drops to zero or near zero.
 
FilterGuy said:
That does not add up. There is a constant current period of charging where the voltage on the charger will be under the target voltage. During this time, the voltage is limited to keep the current at the desired level (or at the max of the charger). Since the voltage is limited, it does not mater what the target voltage is, your not going to "get the ions moving faster". Once the battery starts getting close to full charge the voltage will start rising till it hits the target voltage (Lets say 3.47 volts). Up to this point it does not mater if the charger had been set to a higher voltage.... because that voltage has not yet happened due to the current limitation.

Of course. My misunderstanding. I thought that as the potential difference between the source and the cell was greater, then that moved the ions quicker right through the charge cycle....just realised now, that it only happens during the CV phase once the voltage creeps up. Thanks.
Click to expand...
 
1583615956514.png
The Progressive Dynamics supplies have a fixed target voltage of 3.65V. What they will do is hold it there indefinitely. I am more comfortable with turning off the supply (or at least significantly dropping the voltage).
 
Danny said:
Excellent topic. I really enjoyed the presentation and I'm finding I have been learning a lot from your posts! I have a DC to DC charger and I don't trust it to turn off at goal voltage. Additionally, sometimes we are storing our batteries and don't want to charge them 100% SOC. I have found a cheap voltage sensitive relay module I am using to *TURN OFF CHARGING* at 95% SOC and 50% SOC. This *charger controller* on time 4:58 in the video is my solution to stopping charging before I reach BMS limits.
Click to expand...
@Danny. The setup you show seems to turn off charging at the end of the Constant Current (CC) phase. Is that correct? If so, the batteries never really get fully charged to the target voltage because there is no Constant Voltage (CV) Phase.
 
In my experience the constant current phase ends not when the voltage target is reached but when the current is limited by the battery and not the charger.
FilterGuy said:
View attachment 8709
The Progressive Dynamics supplies have a fixed target voltage of 3.65V. What they will do is hold it there indefinitely. I am more comfortable with turning off the supply (or at least significantly dropping the voltage).
Click to expand...

If I had my preference, when the charge current reaches or decedes $ta amps the charger voltage would drop to 0 or optionally $brv.
Where $ta is termination amperage and $brv is battery resting voltage.
I would like those values to be configurable and with sensible defaults.

For a 100ah 12.8 volt nominal lifepo4 battery meant to be charged at 0.2 c I would set $brv to 13.8 volts and the termination amperage to 0.5 amps.
I would set the cv no higher than 14.4 volts and the cc to 20 amps.
 
Last edited:
smoothJoey said:
In my experience the constant current phase ends not when the voltage target is reached but when the current is limited by the batter


If I had my preference, when the charge current reaches or decedes $ta amps the charger voltage would drop to 0 or optionally $brv.
Where $ta is termination amperage and $brv is battery resting voltage.
I would like those values to be configurable and with sensible defaults.

For a 100ah 12.8 volt nominal lifepo4 battery meant to be charged at 0.2 c I would set $brv to 13.8 volts and the termination amperage to 0.5 amps.
I would set the cv no higher than 14.4 volts and the cc to 20 amps.
Click to expand...
Yup, that is exactly what I would want..... Do you know of one? Do you know of one for a 24V system.
 
ghostwriter66 said:
So not sure if you are agreeing that the Progressive is a Charger or not ...

From where I sit - before we bash progressive Chargers -- it DOES meet the requirement for a termination logic device because it provides a Constant Current/Constant Voltage (CC/CV) charge profile.
Click to expand...
I have not don't my research on these chargers. Can you please comment on the accuracy of the voltage sense at the charger vs the actual battery pack voltage. I'm guessing these chargers don't have a separate battery sense wire?
FilterGuy said:
@Danny. The setup you show seems to turn off charging at the end of the Constant Current (CC) phase. Is that correct? If so, the batteries never really get fully charged to the target voltage because there is no Constant Voltage (CV) Phase.
Click to expand...
Good point. I'm not sure what is happening with my Sterling BB1260 charger but when I left it on it over charged my battery cells. I"m guessing it is CV and my Charge Controller is reading the voltage at the battery. I just charge to 13.8v with the DC DC charger and call it a day and I am happy with 95%+ SOC when connected to shore charger or alternator. My Victron Solar MPPT usually top off the batteries when I am on a trip but I don't really care about being 100% topped off. I"m guessing that you would need a voltage sense wire on a charger if you wanted to really charge to 100%.
 
Well .... to me it's pretty simple ... if it charges a battery, it is a battery charger. Here is a Wikipedia definition: A battery charger, or recharger,[1][2] is a device used to put energy into a secondary cell or rechargeable battery by forcing an electric current through it.

I DO wish the Progressive Dynamics would remove or reduce power to the batttery after it is fully charged ..... and / or allow an easy way to remotely turn it off. If it had that capability or an easy way to remotely turn off the charge, I would probably use one in my RV.
 
@all

I hope you are aware those "chargers" are in fact just servers PSUs with a potentiometer and voltmeter slapped on them.

They are 12 V PSU (it's actually written on the label in the seller's pictures...) that are modded, so be warned they are run far out of their designed specs (12 V +/- 5 %) and they can fail in any way possible (including outputing 12 V when set to 3.6 V to charge one cell...).

Also, they are far cheaper to buy on their own (but you need to mod them yourself), use Liteon PS-2751-5Q as the search keywords; for example https://www.ebay.com/sch/i.html?_from=R40&_nkw=LITEON+PS-2751-5Q&_sacat=0&_sop=15
 
Last edited:
BiduleOhm said:
@all

I hope you are aware those "chargers" are in fact just servers PSUs with a potentiometer and voltmeter slapped on them.

They are 12 V PSU (it's actually written on the label in the seller's pictures...) that are modded, so be warned they are run far out of their designed specs (12 V +/- 5 %) and they can fail in any way possible (including outputing 12 V when set to 3.6 V to charge one cell...).

Also, they are far cheaper to buy on their own (but you need to mod them yourself), use Liteon PS-2751-5Q as the search keywords; for example https://www.ebay.com/sch/i.html?_from=R40&_nkw=LITEON+PS-2751-5Q&_sacat=0&_sop=15
Click to expand...

Check this out ...
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76.36US $ 17% OFF|Voltage Current Adjustable Lifepo4 Lipo Li-ion Lithium Battery Charger 3.65v 4.2v 8.4v 12v 12.6v 14.6v 75a 50a Display 2s 3s 4s - Chargers - AliExpress

Smarter Shopping, Better Living! Aliexpress.com
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ghostwriter66 said:
Just want to make sure that we are on the same sheet of paper with what i am saying - you don't have to agree - just don't misunderstand what i am saying ...

So here goes some rambling ...

We have 1000's of LIFEPO4 batteries operating where I work. Along with that we have probably some of the most recognized experts in the field of EE and Chemistry working for these major oil companies ... Almost all of the experts that I have read have agreed on 3 things.

1. The greatest threat to LIFEPO4 is the stress that it suffers when exposed to HEAT. HEAT is the #1 killer of LiFePO4.

2. Right after that - a second greatest threat is failure from stress when exposed to keeping a LiFePO4 at a high charge voltage.

3. Batteries should be stored for long periods of time with no more than 45% charge.

4. A LiFePO4 battery can be safely and routinely overcharged to 4.2 volts per cell, but at 4.25 there is a break down of the organic electrolytes that can never be recovered from.

For where I work - they tell us that keeping a LiFePO4 battery above 85°F is the start of the "not recommended" scale. As you can imagine I work in South Texas and it was 82 degrees yesterday in WINTER. In summer we will have heat of 120 daily ... so yes - while the engineers agree that anything after 85 there is a gradual ramp up to "REALLY BAD" (157), we do all we can to keep the battery temps as cool as we can ...

FOR US -- we never set our charge voltage higher than the 13.88 volts (3.47 V/per cell). 13.88 is our maximum charge voltage. This is NOT based on anything scientific. And each manufacture has their own recommendations -- This is based on 10 years of our guys using these batteries all over the world. And 100's of engineers running real-world numbers.

For the record - we charge our batteries to about 96% (13.88) and run them down to 10% - and we find that's the best number FOR US to maximize the storage capability of these batteries.

BUT BUT BUT with all of that said -- and if you put 5 EXPERTS in a room you get 7 opinions -- LFP is such a new technology that ppl - even the experts all sort of only agree on about 80% of the stuff out there ... it truly is a new technology that is getting better every day ...

I will tell you though - that there are allot of battery companies that sell LFPs - especially some of the largest US ones - that honestly are just spouting CRAP in order to sell their batteries. Their answers are vague at best and they never can back up their answers with empirical data except "well the CEO has a PHd in something or other" type stuff ... (yes this is a sore point for me)
Click to expand...
OK, here you're saying cut off @13.88V and (3.47V/cell) and that is 96% SOC.
The bottom limit is 10% SOC. What is that in total V and Cell V?
Is there a formula that is easy to use to determine the % of SOC?
I think I remember you posted that when building a new battery pack, you charge the Cells in Parallel to 3.65V.
Is that what you do or just a general recommendation?
 
Sgt Raven said:
OK, here you're saying cut off @13.88V and (3.47V/cell) and that is 96% SOC.
The bottom limit is 10% SOC. What is that in total V and Cell V?
Is there a formula that is easy to use to determine the % of SOC?
I think I remember you posted that when building a new battery pack, you charge the Cells in Parallel to 3.65V.
Is that what you do or just a general recommendation?
Click to expand...

I sort of got out-voted on how to properly TOP Balance batteries ... but both ways are actually right -- I TOP balance in steps just to see if i am going to have any issues with any of the cells being out of whack before I waste time ... Will and others will just go ahead and TOP balance by putting the batteries in parallel and dropping 3.65 (or thereabouts) and as many amps as they can push .. either way is fine ...you get the same results .. I just would rather know right away if I had a bad cell instead of spending 12 hours charging and finding out then ...

BUT YES -- the first time I TOP Balance I push the cells to their limit -- then after that I set the max to be about 88% (85-90%) of the 100% Charge amount and set my lower to 10% .... I just am not one of those ppl that want to purchase a LiFEPO4 and then leave 40% of it unused as some of these guys that will go 80% to 20% ...
 
Looking forward to someone answering Sgt Raven questions from yesterday. I want to understand how to charge a 48v - 600 Ah BB. I LIKE ghostwriter66’s take on this; use the cells capacity. I have seen some charts that show DOD v Voltage; is there some general agreement on what this looks like?
 
Steve_S said:
Tossing a wrench in here... WISH it would have been available I would have ordered this one/
100A 3V to 15V Charger Current Voltage Adjustable
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159.0US $ |100A 3V to 15V Charger Current Voltage Adjustable 3S Lipo Li ion 4S 12V Battery 12.6V 14.6V Lithium 3.2V Lifepo4 Charger RV 50A|Chargers| - AliExpress

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Click to expand...

I stand corrected -- just got off the Chat and the 100A 3V to 15V is 120/240 not just 220 ...
 
Ghostwriter66 - at your work, is there a voltage you use to correspond to 10% DOD ?
 
Dennis Wieske (Progressive Dynamics) discussed with Mike Sokol (RV Electric) use of Progressive Dynamics Converters to charge LiFePO4 batteries.
-This discussion reveals a change in the Progressive Dynamics PD91**ALV converter design currently in progress to change the converter from a one stage charger to a two stage charger (see youtube video starting at 37.3 minutes thru 39.2 minutes and on to 40.3 minutes for more info).
-Battle Born has stated that the PD converters made for use/charging with LiFePO4 batteries at 14.6 v (one stage) are acceptable for use with the B/B battery.
-I am glad to see the change to a two stage LiFePO4 PD**ALV converter. Apparently they will be available soon, if not already available. These 2-stage chargers will replace the one stage charger with no change in product part number. I never did like the single stage fixed 14.6 v converter for charging LFePO4 batteries because it holds the battery at 14.6 v as long as the converter is turned on (plugged in or 120v circuit breaker turned on).

.
 
RandyP said:
Dennis Wieske (Progressive Dynamics) discussed with Mike Sokol (RV Electric) use of Progressive Dynamics Converters to charge LiFePO4 batteries.
-This discussion reveals a change in the Progressive Dynamics PD91**ALV converter design currently in progress to change the converter from a one stage charger to a two stage charger (see youtube video starting at 37.3 minutes thru 39.2 minutes and on to 40.3 minutes for more info).
-Battle Born has stated that the PD converters made for use/charging with LiFePO4 batteries at 14.6 v (one stage) are acceptable for use with the B/B battery.
-I am glad to see the change to a two stage LiFePO4 PD**ALV converter. Apparently they will be available soon, if not already available. These 2-stage chargers will replace the one stage charger with no change in product part number. I never did like the single stage fixed 14.6 v converter for charging LFePO4 batteries because it holds the battery at 14.6 v as long as the converter is turned on (plugged in or 120v circuit breaker turned on).

.
Click to expand...
It's about time!!!! Look at the date this thread started......March of last year. I was complaining to them back then that it was a bad design!
 
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