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12-07-2021, 11:50 AM
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#85
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Senior Member
Join Date: Jan 2014
Location: Safety Harbor, FL
Posts: 2,523
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Quote:
Originally Posted by hclarkx
Sorry, I wasn't clear. I tested each battery individually at 60 amps and then 129 amps for the last 20 minutes down to a bit under 20% SOC.
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Ah I see, still only about 0.5C and the cells are rated for full 1C continuous, although its going to generate some heat.
I tested one of my 206ah SOK's at over 130 amps for about 10 minutes to see if I could trip the BMS and it didn't even though they list 100 amps max discharge, however they are saying unofficially the BMS is actually designed for 150 amps before shutdown, same for charge rate.
I ran both my 206's in parallel at constant 130+ amps with the a/c for three hours to do a full capacity test and they did it no problem but they did hit 125F at the terminals, seemed to be mostly from the BMS at the top of the battery.
__________________
2022 Thor Palazzo 33.5
2016 Jeep Wrangler Unlimited Rubicon Toad - Readybrute Elite Towbar
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12-08-2021, 01:43 PM
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#86
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Senior Member
Join Date: Sep 2017
Location: Northern California
Posts: 1,418
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Quote:
Originally Posted by jharrell
Ah I see, still only about 0.5C and the cells are rated for full 1C continuous, although its going to generate some heat.
I tested one of my 206ah SOK's at over 130 amps for about 10 minutes to see if I could trip the BMS and it didn't even though they list 100 amps max discharge, however they are saying unofficially the BMS is actually designed for 150 amps before shutdown, same for charge rate.
I ran both my 206's in parallel at constant 130+ amps with the a/c for three hours to do a full capacity test and they did it no problem but they did hit 125F at the terminals, seemed to be mostly from the BMS at the top of the battery.
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It does seem that the BMS is the main source of heat in some LiFePO4 batteries. In one early video Will Prowse tested a Battleborn battery at its maximum discharge rate and found the top where the BMS sits to be much hotter than I would be comfortable with. The Overkill BMS that I've been using gets just perceptibly warm under normal use and got only comfortably warm to the touch (in my cold garage) during the 60/129 amp test. The voltage drop across the Overkill seems to be a relatively constant 11 mv indicating around one to two watts of heat when passing around 100+ amps.
I did have one Overkill BMS that got considerably warmer than the others and had higher voltage drop. I mailed it back on a Monday and had a replacement in hand on Thursday.
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12-08-2021, 04:06 PM
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#87
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Senior Member
Join Date: Sep 2017
Location: Northern California
Posts: 1,418
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Quote:
Originally Posted by jharrell
Ah I see, still only about 0.5C and the cells are rated for full 1C continuous, although its going to generate some heat.
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I don't recall seeing a continuous rating on the 280 amp cells that I got. I know the usual thinking is 1C, but personally, I'd be very uncomfortable drawing 280 amps from the cells I have. This, in spite of the terminals on the cells being a generous 3/4" diameter aluminum disk (I've talked to others with quite similar cells that have only 1/2"). However, the terminal torque limits and shallow 6mm thread depth add to my limited comfort level. I was able to lock in the 6mm studs with Locktite 263 but without that I'm not sure one would be safe using the toque spec.
The batteries I speak of will see an occasional 90 amps each and often 50-60 amps each for hours on end. I'm comfortable with that but not much more.
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12-09-2021, 05:08 AM
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#88
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Senior Member
Join Date: Jan 2014
Location: Safety Harbor, FL
Posts: 2,523
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Quote:
Originally Posted by hclarkx
I don't recall seeing a continuous rating on the 280 amp cells that I got. I know the usual thinking is 1C, but personally, I'd be very uncomfortable drawing 280 amps from the cells I have.
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1C charge/discharge is pretty standard with 0.5C recommended charge, all cycle life testing is normally done at 1C/1C (1 hour rate) unlike lead acid which is done at 0.05C (20 hour rate).
Is this your cells?: https://www.evlithium.com/hot-lithium-battery/946.html
__________________
2022 Thor Palazzo 33.5
2016 Jeep Wrangler Unlimited Rubicon Toad - Readybrute Elite Towbar
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12-10-2021, 12:12 PM
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#89
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Senior Member
Join Date: Sep 2017
Location: Northern California
Posts: 1,418
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Quote:
Originally Posted by jharrell
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My cells look exactly like this down to the terminal design, but the listing I bought from did not mention Eve and nothing I received indicated Eve.
Indeed, the 1C charge and discharge rates are indicated as "Max." But, as you note, 0.5C is makes more sense as a limit. And, I think surely less is better in this case and charging at the lowest rate practicable is smart. My present solar array (with 322 Ah battery) rarely gets over 0.16C and, of course, averages much less than this.
Lots of devices have a "maximum" specification that usually means operation close to the point of failure. For the Max discharge listing they say "Preference" which is puzzling. Surely they don't mean 1C is the preferred discharge rate! Maybe it means they prefer you limit discharge to the Max listing but don't rule out occasional higher discharge rates?
I have springs on the way that will put about 240 lbs of force on the end plates; roughly 4-7 psi (depends on how much the cells actually swell, so this is an estimate).
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12-10-2021, 03:42 PM
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#90
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Senior Member
Join Date: Jan 2014
Location: Safety Harbor, FL
Posts: 2,523
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Quote:
Originally Posted by hclarkx
Lots of devices have a "maximum" specification that usually means operation close to the point of failure. For the Max discharge listing they say "Preference" which is puzzling. Surely they don't mean 1C is the preferred discharge rate! Maybe it means they prefer you limit discharge to the Max listing but don't rule out occasional higher discharge rates?
I have springs on the way that will put about 240 lbs of force on the end plates; roughly 4-7 psi (depends on how much the cells actually swell, so this is an estimate).
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Every LifePo4 battery I have seen is rated a 1C charge/discharge with a 0.5C preferred charge rate for maximum life.
If that is your battery this is is cycle life with no compression at a full 1C charge/discharge over and over from the page I linked:
__________________
2022 Thor Palazzo 33.5
2016 Jeep Wrangler Unlimited Rubicon Toad - Readybrute Elite Towbar
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12-17-2021, 12:07 PM
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#91
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Junior Member
Join Date: Dec 2021
Posts: 1
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Conversion to lithiium batteries
Quote:
Originally Posted by RoadTrip2084
My '97 Monaco Dynasty is in need of new batteries.
I would like to invest in a set of 280ah or 300ah LiFePo4 House batteries, most likely assemble them myself from imported cells, etc.
My coach has the original electrical equipment, all in good working order:
- Freedom Model 20 Inverter/Converter (2000w, 100A 3-stage battery charger, no Lithium charge profile)
- 200A Leece Neville Alternator
- 160A Solar Controller (no Lithium charge profile)
Being on a tight budget I would only do this if I can get away with minimal changes to the existing converter, etc.
Since the converter and solar controller lack Lithium charge profiles, I am thinking of two possible configurations that would allow me to keep most of my existing equipment and still enjoy Lithium house batteries.
Configuration #1
1. Use the Gel charge profile settings on the converter and solar controller - Either 14.1 or 14.4v acceptance voltage, w/ 13.8v float charge and 14.1 or 14.4 equalization voltage.
2. Use a 60A DC-DC charger between the chassis battery and the house battery to limit load on the alternator, or disconnect the House batteries from the alternator altogether.
Is it feasible to use the Gel charge settings with Lithium batteries? The top voltage seems alright, I'd be fine with charging to 85-95% of max anyway.
Configuration #2
1. Connect the converter, solar charger, and alternator exclusively to the Chassis battery.
2. Connect the Lithium House batteries to the Chassis battery via the 60A DC-DC charger.
This way shore power, alternator, generator, and solar all charge the chassis battery, and then power is regulated to the Lithium battery at 60A from there. This seems really simple setup-wise, I may lose some efficiencies by putting all charging through the DC-DC charger, but it seems like a reasonable tradeoff.
So what am I missing?
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Derek 775-622-3448 just gave me a nice primer. He works for Battleborn. I contacted him after watching some Will Prose youtube videos. Very impressive videos. The consultation was free and he called me after I logged in the request.
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12-27-2021, 09:16 AM
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#92
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Senior Member
Monaco Owners Club RV Trip Wizard
Join Date: Sep 2021
Location: Airdrie, AB
Posts: 525
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Bit of an update...
I've ordered the following components for my DIY LiFeP04 battery:
- 4 x EVE LF280K cells, w/ welded studs.
- 1 x JBD BMS - 4S 200A Lifepo4 12V Li-Ion Battery Smart Balance Protection Board With Bluetooth Uart
- 3 x Flexible copper/nickel bus bars (Link)
I've used the following values for sizing the battery & BMS:
- Max converter charge current: 100A (12v DC) = 0.35C.
- Max inverter output: 2000W * 86% converter efficiency = 2480W/207A or 0.74C discharge rate.
- The BMS is rated for 200A continuous discharge, w/ 250A for up to 25secs.
I am planning on strapping the cells together with neoprene foam between them and installing them into a standard group 24 battery box. The box will be installed inside the utility closet in the coach basement storage, away from the elements and right next to the converter/inverter.
I've also started a new thread in the Monaco forums regarding my coach-specific wiring changes required to accommodate the new battery, if anyone is interested.
__________________
Ken F.
"Blue Thunder" - 1997 Monaco Dynasty, 36', C8.3 325
2006 Honda Pilot Toad
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12-28-2021, 09:35 AM
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#93
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Senior Member
Join Date: May 2016
Location: St. Maries, Idaho
Posts: 959
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Quote:
Originally Posted by RoadTrip2084
Bit of an update...
I've ordered the following components for my DIY LiFeP04 battery:
- 4 x EVE LF280K cells, w/ welded studs.
- 1 x JBD BMS - 4S 200A Lifepo4 12V Li-Ion Battery Smart Balance Protection Board With Bluetooth Uart
- 3 x Flexible copper/nickel bus bars (Link)
I've used the following values for sizing the battery & BMS:
- Max converter charge current: 100A (12v DC) = 0.35C.
- Max inverter output: 2000W * 86% converter efficiency = 2480W/207A or 0.74C discharge rate.
- The BMS is rated for 200A continuous discharge, w/ 250A for up to 25secs.
I am planning on strapping the cells together with neoprene foam between them and installing them into a standard group 24 battery box. The box will be installed inside the utility closet in the coach basement storage, away from the elements and right next to the converter/inverter.
I've also started a new thread in the Monaco forums regarding my coach-specific wiring changes required to accommodate the new battery, if anyone is interested.
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Ken, I received my EVE cells from Amy last month. They took about 90 days to arrive. Here痴 a picture of my cells with the 200 BMS. I値l install them in a insulated box in the battery bay. I値l also post my install in the Country Coach forum.
Bill
__________________
2003 Country Coach Intrigue 36'
Cummins ISL 400
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12-29-2021, 08:38 AM
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#94
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Senior Member
Monaco Owners Club RV Trip Wizard
Join Date: Sep 2021
Location: Airdrie, AB
Posts: 525
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Quote:
Originally Posted by TR4
Ken, I received my EVE cells from Amy last month. They took about 90 days to arrive. Here痴 a picture of my cells with the 200 BMS. I値l install them in a insulated box in the battery bay. I値l also post my install in the Country Coach forum.
Bill
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Wow those are some fine looking batteries - even have the spring-loaded compression system. Nice work!
Mine is going to be a more basic assembly, space is an issue since I want to keep it inside the utility bay.
Are you using the heating pad connections from the JBD BMS to heat them as well? I'm not going to bother with mine since it will be inside the coach.
__________________
Ken F.
"Blue Thunder" - 1997 Monaco Dynasty, 36', C8.3 325
2006 Honda Pilot Toad
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12-29-2021, 09:58 AM
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#95
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Senior Member
Join Date: May 2016
Location: St. Maries, Idaho
Posts: 959
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Quote:
Originally Posted by RoadTrip2084
Wow those are some fine looking batteries - even have the spring-loaded compression system. Nice work!
Mine is going to be a more basic assembly, space is an issue since I want to keep it inside the utility bay.
Are you using the heating pad connections from the JBD BMS to heat them as well? I'm not going to bother with mine since it will be inside the coach.
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I知 waiting with the heating as well. The battery box I made is insulated (1 foam) and has space for the pads. Bluetooth also has great range.
Bill
__________________
2003 Country Coach Intrigue 36'
Cummins ISL 400
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03-26-2022, 07:55 PM
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#96
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Senior Member
Monaco Owners Club RV Trip Wizard
Join Date: Sep 2021
Location: Airdrie, AB
Posts: 525
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Well I have a minor update, I've finally gotten my battery assembled and operational - 280Ah, 200A BMS, Bluetooth.
Here's some glamour shots:
I've decided to install the battery in the utility closet in the basement storage, right beside the inverter/converter. It is inside a regular group 27 battery box with some foam around it for insulation/vibration deadening.
I'm also going to make my old house battery connection in the battery tray into my chassis batteries since then I can connect both of the batteries I have instead of just one. All this will require some reworking of the wiring in the rear electrical panel in the engine bay.
I've started by removing the old diode-based battery isolator and Lampert chassis battery maintainer, along with the Big Boy booster solenoid and a couple of the 150A fuses from the back panel to make room for my 60A DC-DC charger. The old fuses are no longer required since the new battery will have a 300A fuse between it and the converter (and the rest of the coach).
I hope to get all the electrical changes done and the battery installed and working by next weekend sometime.
__________________
Ken F.
"Blue Thunder" - 1997 Monaco Dynasty, 36', C8.3 325
2006 Honda Pilot Toad
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03-27-2022, 09:09 AM
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#97
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Senior Member
Join Date: May 2016
Location: St. Maries, Idaho
Posts: 959
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Quote:
Originally Posted by RoadTrip2084
Well I have a minor update, I've finally gotten my battery assembled and operational - 280Ah, 200A BMS, Bluetooth.
Here's some glamour shots:
Attachment 360438
Attachment 360436
Attachment 360437
I've decided to install the battery in the utility closet in the basement storage, right beside the inverter/converter. It is inside a regular group 27 battery box with some foam around it for insulation/vibration deadening.
I'm also going to make my old house battery connection in the battery tray into my chassis batteries since then I can connect both of the batteries I have instead of just one. All this will require some reworking of the wiring in the rear electrical panel in the engine bay.
I've started by removing the old diode-based battery isolator and Lampert chassis battery maintainer, along with the Big Boy booster solenoid and a couple of the 150A fuses from the back panel to make room for my 60A DC-DC charger. The old fuses are no longer required since the new battery will have a 300A fuse between it and the converter (and the rest of the coach).
I hope to get all the electrical changes done and the battery installed and working by next weekend sometime.
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Looks great Ken! If I had to do it over again, I壇 probably skip the cell compression springs. Your supposed to get more cycles, but these batteries will outlast me anyway. Plus you can put them in a smaller box.
I致e now added heating and fan cooling to my enclosure. The heating has two settings, Hi and Low. Pictures here;
https://www.irv2.com/forums/f112/diy...ll-568880.html
Bill
__________________
2003 Country Coach Intrigue 36'
Cummins ISL 400
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03-27-2022, 11:07 AM
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#98
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Senior Member
Fleetwood Owners Club Ford Super Duty Owner
Join Date: Jun 2012
Location: SoCal
Posts: 15,749
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Considerations of using a charger not designed for lithium batteries:
1) voltages.
A multistage converter/charger designed for lead acid will typically have absorb and float stage voltages that are ok for lithium.
If a basic fixed voltage converter that outputs only 13.x volts, it likely will not fully charge lithium nor allow them to reach balancing voltage.
2) absorb time.
A lead acid charger typically expects the battery bank needing hours of time in absorb. Lithium does not. See what control you have over this.
3) Charge cycle compatibility.
A multistage charger not designed for lithium may not transition through the charge cycle correctly or restart the charge cycle correctly (I had a older xantrex inverter/charger. With lithium it would exit bulk early and move to floating).
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So... you can try the charger you have, selecting, if selectable, a charge profile with closest appropriate voltages for absorb and float, adjusting absorb time as available, and give it a try. But have a backup plan should it not perform adequately.
This $35 gizmo has a feature that charts voltage over time. With it you can see the charge cycle working properly, or not.
Bluetooth Battery Monitor Auto... https://www.amazon.com/dp/B074ZCM6YC...p_mob_ap_share
__________________
Vince and Susan
2011 Tiffin Phaeton 40QTH (Cummins ISC/Freightliner)
Flat towing a modified 2005 Jeep (Rubicon Wrangler)
Previously a 2002 Fleetwood Pace Arrow 37A and a 1995 Safari Trek 2830.
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