Upgrade to Lithium

[JEH]

Thanks Mark.

[Chateau_Nomad]

My 30 year old son was having problems with charging the battery in our grandson's electric jeep. He didn't have a voltmeter, so I bought him one and showed him how to measure DC current from the 12 volt battery.

Although he inherited the common sense gene, I told him emphatically NOT to mess with electricity if you're not sure what you're doing... because it will indescriminatly KILL YOU.

[JEH]

Thanks Chateau

[JEH]

It looks like this is what I need with one 400Ah LiFePO lithium battery.
Progressive Dynamics
80A converter
Model 9180 ALV
https://www.progressivedyn.com/pd9100l/


1. Opinions?
2. Is it correct that it will put out 80A less efficiency loss when connected to the Onan 4000k generator?
3. If I need 120 Ah charge, it should take two hours at 60A, correct?

Thanks.

[16ACE27]

Originally Posted by Chateau_Nomad

My 30 year old son was having problems with charging the battery in our grandson's electric jeep. He didn't have a voltmeter, so I bought him one and showed him how to measure DC current from the 12 volt battery.

Although he inherited the common sense gene, I told him emphatically NOT to mess with electricity if you're not sure what you're doing... because it will indescriminatly KILL YOU.

You bought him a voltmeter to measure current?

No wonder people get confused.

[Mark54]

Originally Posted by JEH

It looks like this is what I need with one 400Ah LiFePO lithium battery.
Progressive Dynamics
80A converter
Model 9180 ALV
https://www.progressivedyn.com/pd9100l/


1. Opinions?
2. Is it correct that it will put out 80A less efficiency loss when connected to the Onan 4000k generator?
3. If I need 120 Ah charge, it should take two hours at 60A, correct?

Thanks.

The WFCO 8955 that comes in your RV is 55A, so if you go to an 80A one, you will likely need to change/upgrade the wiring and fuse, for that for the extra amp draw.

The generator should be able to handle anything (as long as it's 20A input) you plug into it- so 50 or 60A output is not an issue. 80A converter is ok only by virtue of the wire gauge and fuses involved, being the right size. 80A converter will draw more amps from the panel, so important to make sure the wire gauge can handle it. I would say not, if designed for 55A, so make sure it's enough. There is usually a separate fuse on the + cable coming out of the converter rated for the output of that converter as well.

The PD9145ALV would be appropriate for your system- 45A converter- If you go to the PD9160ALV, 60A, an upgrade from your 55A one, then you might get away with it, but will need an RV tech to verify the wire gauges in your RV.

The 9100 series is correct for lithium. I had a PD9145ALV in my Rialta (changed to lithium system) and was a very reliable charger. The PD9145ALV and 9160ALV just plug into an already existing outlet, 20A, in your RV.

The PD series are also 'smart charger' and will regulate the charge amount relative to the SOC, in other words, will charge at 14.6V (aka 'bulk charge') and step down to 13.6V once fully charged ('Float charge') automatically.

If you put 400Ah lithium battery in, you will have 12x400= 4800Wh, enough to run a 1000W device for 4.8 hrs.
Since you already have 400A battery bank, there should not be an issue going to Lithium in that regard.

Did you verify measurements for placement in your RV? I would assume you are replacing with 4 ea. like sized batteries, only lithium this time. You may have group 31 AGMs- so just make sure the lithiums are same size, so you can use the same trays and hold-downs. Sometimes the connections on the batteries may differ- AGM might have old style posts, and Lithiums may have threaded inserts and bolts, so the cable end connections may have to be changed.

Also How many watts do you need at any given time? If you are using more than 2000W at once, then you may need to upsize the battery cables. If you are not increasing your usage, and are under the 2000W, then you may be ok, but again need to verify with an RV tech who knows RV electrics.
Also may have to change the converter to a 3000W one to handle larger loads. Then bigger fuse and battery cables as well. The 2000W inverter you have now will shut down if you overload it, as long as it is designed to do so, and most are.

So lots to consider.

Theoretically, a 45A charger will charge that battery in a little over 10 hours if drained to 0% SOC (state of charge). Best to cycle lithium batteries from 20% to 80% for longest life. Only way to do that is by watching a meter, hopefully that is somewhere in your RV so you can see the levels of charge. Do you have a battery readout anywhere in your rig?

Google "Mobile RV techs near me" and see who pops up. Forget the dealers- they are generally clueless. You want someone who knows a LOT about RV electrics and have done many conversions/ installations. Some have websites that show their work.

I have one near me that impressed me with a bread truck power system he installed. He showed that he knew more than me, so I use him for advice.
Like restaurants, I only go if they cook better than I do!

Don't do anything w/o talking to one of these experts!

Keep asking questions- you're doing fine.

[JEH]

Outstanding Mark. Thanks.

I have two power monitors. I've only got 1 - 20 A breaker and it is for the air conditioner. The converter is on a 15A breaker. Also, at 50% SoC, when I turn the generator on, I get a +20A reading on the power monitor and it drops to about 5+ after about 6-8 hours. The converter is new. It's output is 13.6V. When I started the motorhome after the third night without running the generator, the power monitor showed +50A dropping to about +44A after about an hour. The battery Ah came up by about 50A after an hour or so.

Questions:
1. If I put in a PD9160ALV (recommended replacement by Progressive Dynamics for a WF 8955) how long would it take the batteries to charge or what would the real A output be from the converter?
2. Do lithium batteries charge faster than AGM?
3. Do lithium batteries charge at the same Amp rate throughout the charging time?
4. Any clue why the existing converter only seems to read +20A when first charging and drops to 5% at about 75% SoC?

Here is an interesting link I found on the subject.
https://www.progressivedyn.com/lithi...acement-units/

And a wire size guide.
https://www.bluesea.com/support/arti...r_a_DC_Circuit

[Chateau_Nomad]

Originally Posted by 16ACE27

You bought him a voltmeter to measure current?

No wonder people get confused.

Just like getting a "Xerox copy" on a Minolta photocopier... or a "Kleenex" out of a Puffs facial tissue box. I cold go on, but I'll spare the boredom.

Have you ever seen a cement floor? I prefer sand and gravel with just a cement binder... Oh STOP!!

[16ACE27]

Originally Posted by Chateau_Nomad

Just like getting a "Xerox copy" on a Minolta photocopier... or a "Kleenex" out of a Puffs facial tissue box. I cold go on, but I'll spare the boredom.

Have you ever seen a cement floor? I prefer sand and gravel with just a cement binder... Oh STOP!!

Not even the same thing.

A voltmeter measures VOLTS in volts
An ammeter measures CURRENT in amps
Am ohmmeter measures OHMS in ohms

3 completely different parameters in the electrical world.

A multimeter cam measure all 3 and usually more such as frequency and capacitance.

I could go on.

[Chateau_Nomad]

I do know the difference... otherwise I wouldn't have passed my Amateur Radio exam... twice.

Actually... you measure "resistance" which is indicated in ohms.

Okay... we're done now.

[Mark54]

Originally Posted by JEH

Outstanding Mark. Thanks.

I have two power monitors. I've only got 1 - 20 A breaker and it is for the air conditioner. The converter is on a 15A breaker. Also, at 50% SoC, when I turn the generator on, I get a +20A reading on the power monitor and it drops to about 5+ after about 6-8 hours. The converter is new. It's output is 13.6V. When I started the motorhome after the third night without running the generator, the power monitor showed +50A dropping to about +44A after about an hour. The battery Ah came up by about 50A after an hour or so.

Questions:
1. If I put in a PD9160ALV (recommended replacement by Progressive Dynamics for a WF 8955) how long would it take the batteries to charge or what would the real A output be from the converter?
2. Do lithium batteries charge faster than AGM?
3. Do lithium batteries charge at the same Amp rate throughout the charging time?
4. Any clue why the existing converter only seems to read +20A when first charging and drops to 5% at about 75% SoC?

Here is an interesting link I found on the subject.
https://www.progressivedyn.com/lithi...acement-units/

And a wire size guide.
https://www.bluesea.com/support/arti...r_a_DC_Circuit

1) @60A, (supposed actual output), 400Ah battery system should take 6-7 hrs to charge from 0% SOC. Just divide battery amps by charger, and maybe add a little as it slows down near the end. I find that if I just divide the residual amps by the charging amps, it;s pretty close.

I use an Inverter/converter (2000W, 45A, respectively) to charge my 300A batteries during storage, and typically takes about 3-4 hours to get 150A (half of 300A) back. I store them at 50% during the winter and charge to 100% and discharge back to 50% every 3 months. I use the inverter function with a small 750W heater to discharge in my basement.

If you store your LFP batteries inside, charge/discharge each independently, then charge all to 100% and put back in camper in springtime if you remove them to store like I do.

2) About the same afaik, but read this article: https://www.powercurrents.com/articl...u-need-to-know

3) Amps the same, voltage varies with LFP from 14.6 bulk to 13.6 float charge

4) Existing charger will drop to lower rate when battery starts to get 'full' so must be a 'smart charger'. Bulk to float thing again.

Both good articles- I use Blue Sea breakers on my solar charge controller- great company. I like the cross reference chart! Verifies the selection of the PD9160ALV.

Remember it's about what you use in amps as opposed to what is available for amps from the battery bank. The availability just tells you how long you can use the power you're drawing.
Like I said from the beginning, I find watts easier to use and rely on for how much I can use. AC or DC, watts are watts. If you are 'inverting' to 120VAC, then your 4800Wh of batteries can power 1200W for 4 hrs.

12V @ 100A, is the same as 120V at 10A.
Both are 1200W. About the same as a toaster.



Good work!

[macdaddy1111]

Originally Posted by 16ACE27

Not even the same thing.

A voltmeter measures VOLTS in volts
An ammeter measures CURRENT in amps
Am ohmmeter measures OHMS in ohms

3 completely different parameters in the electrical world.

A multimeter cam measure all 3 and usually more such as frequency and capacitance.

I could go on.

It's amazing what 100 or so dollars can do in one hand!

The piles of crap we us to drag around up and down on board ship! Simpsons volt meter hanging upside down on the top of mast!

Now that and everything else in a kit in draw!

[JEH]

Thanks Mark.

So why does a 55A rated converter only put out 20A when it starts charging AGM batteries at 50% SoC?

i.e. something else is screwed up and the result will be the same with a swapped out converter?

[Bob Nodine]

Originally Posted by JEH

Thanks Mark.

So why does a 55A rated converter only put out 20A when it starts charging AGM batteries at 50% SoC?

i.e. something else is screwed up and the result will be the same with a swapped out converter?

You can avoid all this hassle by purchasing a high current charger that is suited for lithium batteries and connect it directly to the batteries. I have an external charger I purchased for my garage at home that will automatically adjust for the battery type when it is connected. Power it from shore power or the generator. Provide a switch to turn it off and on if one is not already present. Use it when you need it and turn it off when you don't. Leave other sources of charge, solar, converter, etc. connected as is. Many owners of large motorhomes who boondock often will add high current chargers in parallel with other charging sources when they want a quick charge on the battery bank. You just have to make sure you don't overload the AC power source (shore, generator, etc.).

[DavidEM]

Originally Posted by JEH

Thanks Mark.

So why does a 55A rated converter only put out 20A when it starts charging AGM batteries at 50% SoC?

i.e. something else is screwed up and the result will be the same with a swapped out converter?

Because it is a crappy converter. Reread my post #8, first paragraph above.

We seem to be going round in circles on this topic. I believe most if not all of your problems would be solved with a new PD converter and wiring your solar panels correctly to an appropriate sized MPPT controller.

David

[16ACE27]

Originally Posted by JEH

Thanks Mark.

So why does a 55A rated converter only put out 20A when it starts charging AGM batteries at 50% SoC?

i.e. something else is screwed up and the result will be the same with a swapped out converter?

Converters rarely charge at full rate (Bulk charging), especially when in parallel with another charging system (solar) that artificially inflates the battery voltage.

So it kicks into absorption mode which is what you see at 20 amps.

[Mark54]

Originally Posted by JEH

Thanks Mark.

So why does a 55A rated converter only put out 20A when it starts charging AGM batteries at 50% SoC?

i.e. something else is screwed up and the result will be the same with a swapped out converter?

Not sure- could be faulty, or a wire is loose, or something else- also as As 16Ace27 says, has a power curve, but that seems low, unless it's at the 'float charge' segment of the curve.
interesting article about the WFCO 55A converter- evidently has inherent problems:
https://www.camperupgrade.com/wfco-5...oubleshooting/
I would dump it and get a PD9160ALV asap. Much better unit.

[DavidEM]

Ok, here are the specifics of my experience with the WFCO 8955 to buttress my claim that it is a POS:

On my new (2021 at the time) Axis I never saw charging while on shorepower above 20 amps, often maybe 10 or less even with the 200 Ahs of AGMs at 75% SOC. It acted exactly like a cheap fixed voltage output charger.

So I replaced it with a PD 60 amp converter with “Charge Wizard”. I then ran the batteries down to 75% the next time we went camping and it put out about 40 amps and then started dropping after the batteries reached 90% SOC, which is exactly how a good three step charger should operate.

So I am convinced that the WFCO is a fixed voltage charger and the PD is a three step charger. Having said that, the 90% of RV owners who camp at FHU sites will never know the difference.

David

[Mark54]

Originally Posted by DavidEM

Ok, here are the specifics of my experience with the WFCO 8955 to buttress my claim that it is a POS:

On my new (2021 at the time) Axis I never saw charging while on shorepower above 20 amps, often maybe 10 or less even with the 200 Ahs of AGMs at 75% SOC. It acted exactly like a cheap fixed voltage output charger.

So I replaced it with a PD 60 amp converter with “Charge Wizard”. I then ran the batteries down to 75% the next time we went camping and it put out about 40 amps and then started dropping after the batteries reached 90% SOC, which is exactly how a good three step charger should operate.

So I am convinced that the WFCO is a fixed voltage charger and the PD is a three step charger. Having said that, the 90% of RV owners who camp at FHU sites will never know the difference.

David

Well put- The PD chargers are the best!!
At first, I thought FHU ("full hook up" for newbies) had a different first word, or was re-arranged from FUH...:-)
I'm slow today.

[JEH]

Mark -
"I would dump it and get a PD9160ALV asap. Much better unit."
Am I correct the PD`9160ALV only works with lithium so I will have to swap out the AGMs to install it?
Jim