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Older converter compatibility with SOK Lithium 206ah battery

Off Gridin' It

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Older converter compatibility with SOK Lithium 206ah battery

I am installing a 206ah Lithium battery in on old 1984 RV.
It has a 7445 45 Amp 7400 Series Converter Charger.
I am replacing two 78ah Lead batteries.

Here are the specs on the DC Output of the converter/charger.
DC Output - volts - 13.85 max @ no load and 13.2 min @ full load , Amps 45

The charge voltage of the SOK battery is 14.6 volts so it may not charge very fast at that voltage.
From what I can see this should be ok for the lithium batteries.

Can anyone see any reason why this won't work or might damage the SOK battery?
 
You'll need to change out the converter to one that will charge lifepo4 batteries. If you install a lager converter over 45 amps then you'll need to change to larger wiring too.
 
From what I can see this should be ok for the lithium batteries.

Rank speculation follows.

AFAIK full charge for 4S LiFePO4 is a little under 13.8v -- overvolting to the 14s is for top-balancing and increasing charge rate.

I would test-drive the converter for charging the SOK. Caveats:
  1. one might want to use solar or some other charging source to hit the 14s occasionally for top-balancing, especially if using higher discharge rates.
  2. I'd watch what voltage the converter holds the battery at in practice ("13.85 max @ no load and 13.2 min @ full load"). I'd like to see 13.2-13.6v for long-term use on shore power. Higher than that might cause the degradation we see when holding 100% SoC too long.
 
I ended up talking directly to SOK with some of my concerns and they say it will be fine that the older converter will not damage the battery but that it will only charge to about 85%. So later the converter can be upgraded and it doesn't need to be done right now since there is enough solar to keep the batteries charged.
 
I had a similar question and response from SOK. In my case, their take on upgrading my charger was “why bother?”
 
I have basically the same questions.
I have an Aliner 2020 Ranger 12 RV with a WFCO converter WF-8735P. I also have a Renogy Rover Elite 20amp MPPT CONTROLLER and I do have a portable 100 W solar panel. I am trying to decide to replace the LA battery that came with my Aliner with a AOK lithium battery ( either 100ah or 206ah does it matter for the controller or converter?). If I do that do I need to change the converter as well? We never seem to camp where there is shore power so plugging in the camper is not normal for us. We like wilderness camping and usually stay about a week. I do have the portable 100 W solar panel and my Renogy MPPT 20 amp controller that will work with a lithium battery. We do not have a microwave or AC in the small camper. About the only draw on power is the frig fan, the heater fan, the exhaust fan, lights and charging iPads and iPhones.
So do I need a new converter? What size wire should I run from the controller to the battery? I haven’t permanently set anything up but have used the portable system to top off my LA battery.

Thanks again for your answers
 
About the only draw on power is the frig fan, the heater fan, the exhaust fan, lights and charging iPads and iPhones.
You REALLY need to quantify this in watt hours used daily. 100W solar panel sounds very undersized off hand.

If your daily use adds up to 3000Wh for example, and assuming 5 quality solar hours difficult in winter!), that would require
600W of solar panels:

3000Wh / 5h = 600W solar panels.
And even then, 600W / 12.8V = 47A solar charger to use all 600W.

If you have more info we can run numbers for your situation.
 
I have the same issue and I just left my old charger in place. I will let solar top off the batteries.
 
You REALLY need to quantify this in watt hours used daily. 100W solar panel sounds very undersized off hand.

If your daily use adds up to 3000Wh for example, and assuming 5 quality solar hours difficult in winter!), that would require
600W of solar panels:

3000Wh / 5h = 600W solar panels.
And even then, 600W / 12.8V = 47A solar charger to use all 600W.

If you have more info we can run numbers for your situation.
Thanks for the information. I am not sure how I can calculate the Wh as we are very new to all of this but I do understand what you are saying. The lights are all led and the various fans are run very little. I will look at the various manuals to check the wattage for the fans. So if a particular fan is listed at x watts how do I calculate what that is in wh? Do I need to know how many amps the fans willl draw? Sorry for the dumb questions. Still learning here.
Thanks
 
So if a particular fan is listed at x watts how do I calculate what that is in wh?
If a fan is 50W and you run it for 5 hours, that is 250Wh. Run for 2 hours, its 100Wh.

Similarly, if you get the amps (and voltage, 12V vs 120V):
5A fan at 12.8V = 64W
64W run for 8h = 512Wh

3A fan at 120V = 360W
360W for 2h = 720Wh

You need this total as close as possible for each day as that is the amount of solar you need to harvest each day.
 
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