time2roll

Southern California

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Joined: 03/21/2005

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Place them inside where it is warm.
2001 F150 SuperCrew
2006 Keystone Springdale 249FWBHLS
675w Solar pictures back up
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pianotuna

Regina, SK, Canada

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time2roll wrote: Place them inside where it is warm.
Hi time2roll,
If I were full time, maybe. But as a part timer my storage requirements are -40.
Regards, Don
My ride is a 28 foot Class C, 256 watts solar, 556 amp hours of AGM in two battery banks 12 volt batteries, 3000 watt Magnum hybrid inverter, Sola Basic Autoformer, Microair Easy Start.
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time2roll

Southern California

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OK and the storage spec is -35C. Even at -40 the battery would retain some of the average temperature. Or just bring it home for storage. Although at 100 pounds it might be a hassle.
For a few $$ more there is same with added heating element. Need power though.
* This post was
edited 02/16/20 10:19pm by time2roll *
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librty02

Western Pa

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Housted wrote: I just put 3 Battleborn 100 Ahr batteries in place of 400 Ahr of AGM.
I have 1050 watts of solar and after much consultation with BB my
converter is fine as is my solar controller, which is programable.
I was impressed with their construction and assembly methods.
I thought about making my own pack, but, could not find an external BMS I would trust. ![frown [emoticon]](https://forums.goodsamclub.com/sharedcontent/cfb/images/frown.gif)
Our experience boondocking with the BB Lithium is fantastic. The voltage stays very constant througout discharge and they provide up to 300 A if needed. Highest I have seen (microwave) is 140 amps to the inverter.
They seem like a solid company and all is assembled in the USA.
Housted
Hey Housted what converter is it you have that BB said was fine just curious, what is the charge rate? I am looking to upgrade myself and am doing some research on all of this.
TIA
2011 FORD F-150 FX4 CREW CAB ECO...
2018 Ford F-150 Max Tow Crew 6.5 3.5 Eco...
2013 Keystone Passport 2650BH, EQUAL-I-ZER 1K/10K
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3 tons

NV.

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BFL13 wrote: "In my mind, the ideal Lifepo4 charger would offer adjustable charge voltage (Like the PowerMax - but with a higher limit), and be a two stage design (though float is not necessary, nor harmful) so that the battery does not sit for an extended period while being held at maximum voltage..."
What limit is desired? It goes to 16.5v now.
It is adjustable single voltage (which does two battery "stages", bulk and absorption), but you want a charger end's two-stage.
Not sure how you can have a two-stage (at the charger) adjustable voltage that is automatic as seems to be desired here. You would need an adjustable timer to go with that, but that would need a trigger since you want the battery to get fully charged first and you don't know how long that will take.
The trigger would have to "see" that the battery is full somehow, and voltage can't be the trigger of course. However, it may be ok with Li batts, which start their absorption stages at a high SOC and you don't want them to be all the way full?
Thanks, upon a deeper dive I can now see that the powermax voltage does go much higher than is illustrated in the charge profile chart...By ‘two stage’ my desire was simply to not have the charger remain in absorption for extended periods...
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BFL13

Victoria, BC

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Battle Born suggests the adjustable voltage PowerMax be used in its adjustable voltage mode set to 14.4v. They do not say, but of course at some point soon after reaching a full charge you would crank the voltage down to 13.6. Timing for that is not automatic.
Battle Born also wants their batts to have 20-30 minutes of absorption time, suggesting that time be set on chargers that have such timers (like some solar controllers and the fancier chargers in inverter/chargers).
The Bulk stage ends and Absorption begins about when battery voltage reaches charger voltage and amps then taper. However with Li batts AFAIK, this moment is not so obvious at all, and amps remain near charger max to a very high battery SOC.
I don't know how you can tell where you are at so you can note when to start the clock for the 20-30 minutes. Or indeed, how an automatic charger or controller can tell.
I also don't know how you can tell the battery is fully charged. It might have to do with the cell balancing gizmo. Not clear on what I read there, but it might give some indication it has done its trick at the end of a recharge. ??
Anyway, there seems to be a lack of information on just how you would be able to tell what you are doing when recharging an Li bank. It may be that I just haven't seen it.
EDIT--this is good! Note full charge is when amps taper to 3-5% of AH.
https://batteryuniversity.com/learn/article/charging_lithium_ion_batteries
Looks like you could get by ok with a charger set to 14.4v and on a timer for its 120v once you know from experience how long it takes to get to where you want to be for SOC.
That would let you do a recharge without having to be there to stop the charge before it is too late and you go into an overcharge.
* This post was
edited 02/20/20 09:56am by BFL13 *
1. 1991 Oakland 28DB Class C
on Ford E350-460-7.5 Gas EFI
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2. 1991 Bighorn 9.5ft Truck Camper on 2003 Chev 2500HD 6.0 Gas
See Profile for Electronic set-ups for 1. and 2.
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bdosborn

Colorado

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Joined: 03/26/2006

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How about something like this:
Jackery Portable Power Station
Here's annoying Will doing a review on different models.
Annoying Will
Bruce
2010 6.5'X11' TTT - Boxcar
Custom Frame, Poptop, AC, Espar Diesel Furnace, HW Heater, Sink, Shower, 12V-120V, LED Lights, TV and XM Radio, DVD Player, 300W PV Panels, PD 9140 Charger, Tongue Box, Filon Exterior, 1000W Generator, Patient Wife
Boxcar Build
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pianotuna

Regina, SK, Canada

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240 watt hours is a joke. I use 100 watt hours to make a pot of coffee.
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bdosborn

Colorado

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You didn't read what the OP was asking for.
Quote: Ahhhhh...
Ah cheap as in "Honey, forget Taco Bell's 99 cent special. Tonight we dine at Costco's food court".
AMAZON?
Was mulling something around 10 lbs 5 Kg that could be controlled drained to 0% and used with a BiPAP away from home in an outage. A nifty critter with remote 10 watt LED lamp and USB charger for an eBook.
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