How big an RV Converter for my 280AH Build?

[bass-o-matic]

Howdy.

I'm in the process of building an 280AH EVE battery. This will be the only battery in my very small RV. Currently I have a 45 Amp Progressive Dynamics Converter. I just got the 45 Amp Progressive Dynamics PD 9145AL still in the box. My camper doesn't run much. Fans. Lights ( all LED ). Stereo. A mini fridge on a 2000w inverter is probably the big draw. I have 300w of solar and an Epever Controller.

1. I read that I really only need a 30 amp charger. Slower is better. To a point.
2. The "AL" is an older single stage Charger... I want the ALV... dual stage right? Or does it matter. I paid for the ALV... they sent me the Al although that is another matter.
3. Any other brands I should look at?

Cheers!

 

[Zapper77]

Take a look at

EG4 Battery Charger | 12V 30A

Signature Solar provides solar panels, off-grid solar systems, grid-tie, and hybrid systems. Quality solar inverters, bifacial solar panels, complete solar kits, solar batteries. Featuring brands such as EG4 Electronics with their solar battery, LifePower4 and EG4 LLifePower4 and EG4 LL

signaturesolar.com

I have the PD80 amp lithium charger and it's extremely inefficient. Coming in at only 45%


I own the 48v version of this EG4 charger and the efficiency is above 90%.

*While I don't own the 12v version...I hope the efficiency is the same.

 

[MisterSandals]

Currently I have a 45 Amp Progressive Dynamics Converter. I just got the 45 Amp Progressive Dynamics PD 9145AL still in the box.

I have the same PD4645 as you have and decided that it was better than the PD9145AL because the newer lithium aware charger charges to 14.4V and floats at that level too (if my memory serves me correctly).
I am not sure my LiFePO4 cells will behave at that high voltage and I am a conservative charger and only charge to 13.88V with solar. I think my PD4645 charges to 80-90% (cannot remember the voltage, sorry) which is good enough since i have a 412Ah (2P4S) battery. And i charge with solar (330W, Victron 100/30) except for a couple days a year at RV parks/campgrounds with shore power.

What is the problem you are trying to fix with a new charger?

 

[bass-o-matic]

I have the same PD4645 as you have and decided that it was better than the PD9145AL because the newer lithium aware charger charges to 14.4V and floats at that level too (if my memory serves me correctly).
I am not sure my LiFePO4 cells will behave at that high voltage and I am a conservative charger and only charge to 13.88V with solar. I think my PD4645 charges to 80-90% (cannot remember the voltage, sorry) which is good enough since i have a 412Ah (2P4S) battery. And i charge with solar (330W, Victron 100/30) except for a couple days a year at RV parks/campgrounds with shore power.

What is the problem you are trying to fix with a new charger?

Thanks. Nope. I'm upgrading to LiPo from Lead Acid. Pulling my new Trojan T105s out and all... because why not! Also, I was thinking of the Converter / Charger differences... I'm not sure that matters for me? When I'm on shore power I literally unplug my fridge from the Inverter and plug it into shore power. I built my own trailer ( took 7 years of weekends ) so I just kept the AC and DC systems separate to keep it simple. So, when I'm on shore power ... I'm mostly running some 12v lights or fans off the batts.... so I THINK a charger is just fine? Right? Here is my trailer... built it from scratch... not a remodel... sccccratchh.... lot's of buck rivets https://photos.app.goo.gl/9JiPgtRnyPcjESEU6

 

[bass-o-matic]

Take a look at

EG4 Battery Charger | 12V 30A

Signature Solar provides solar panels, off-grid solar systems, grid-tie, and hybrid systems. Quality solar inverters, bifacial solar panels, complete solar kits, solar batteries. Featuring brands such as EG4 Electronics with their solar battery, LifePower4 and EG4 LLifePower4 and EG4 LL

signaturesolar.com

I have the PD80 amp lithium charger and it's extremely inefficient. Coming in at only 45%

I own the 48v version of this EG4 charger and the efficiency is above 90%.

*While I don't own the 12v version...I hope the efficiency is the same.

Wow, That is a sexy charger if I may say so myself.

 

[MisterSandals]

I'm upgrading to LiPo from Lead Acid. Pulling my new Trojan T105s out and all... because why not!

Hopefully LiFePO4 and not the explody lithium polymer (LiPo).

Yes, thats what i did and assumed you were doing.

Also, I was thinking of the Converter / Charger differences... I'm not sure that matters for me?

Ah, a trailer, so probably not use alternator charging.

I'm mostly running some 12v lights or fans off the batts.... so I THINK a charger is just fine?

Yes, converter "could" supply 12V for your loads but it sounds like you do not use that either. If you are setup to run directly from battery, you've eliminated (bypassed?) the advantages over just a battery charger. Conversely, i still don't see what you are trying to gain by changing from your PD4645. Smaller size? More charging control to get 10% more out of your battery?

Which begs the question about how well your battery behaves at a high state of charge? Are the cells balanced enough to accept a high charge voltage? What BMS?

Here is my trailer... built it from scratch... not a remodel... sccccratchh.... lot's of buck rivets

Sweet! You have nice design and fabrication skills.

 

[bass-o-matic]

Hopefully LiFePO4 and not the explody lithium polymer (LiPo).

Yes, thats what i did and assumed you were doing.

Ah, a trailer, so probably not use alternator charging.

Yes, converter "could" supply 12V for your loads but it sounds like you do not use that either. If you are setup to run directly from battery, you've eliminated (bypassed?) the advantages over just a battery charger. Conversely, i still don't see what you are trying to gain by changing from your PD4645. Smaller size? More charging control to get 10% more out of your battery?

Which begs the question about how well your battery behaves at a high state of charge? Are the cells balanced enough to accept a high charge voltage? What BMS?


Sweet! You have nice design and fabrication skills.

Thanks! Right LiPo4 from The Alibaba.... first time buying there... probably overpaid a bit https://www.alibaba.com/product-det...a2756.order-detail-ta-ta-b.0.0.79412fc2ntChfo Cells arrive tomorrow. I will build the case, with "fixture" and 2mm EVA between the cells, Top charge them and then capacity test them. I have the power supply to top charge at 3.65 ready and the Capacity tester recommended by Will. I have a 120A OverKill BMS waiting in a box with 6mm lugs attached. I'll be making my own Bus bars with 2AWG Welding cable. I have the lug crimper.. just in case the batts "flex". I'll put silicone heating pads under the box on a thermostat.... probably publish my schematics before I put it all together just to get some input....
Seems like fun so far....

 

[bass-o-matic]

I think I'm overthinking something. I don't really need a Converter. Just a charger. For my small system. Right? I mean they both just plug into the battery.... and charge it.... I'm not understanding how the Converter does something special. Clearly it does. But they both plug into the battery... and all my load is off the battery. ( well, after the shunt ). What am I missing?

 

[MisterSandals]

What am I missing?

I think you got it. You are not using the converters features (alternator charging and 12V from shore power) except charging.