Lithium Battery

[Jon R]

Just more data for you:

I have a 200 ah battery from bigbatteries.com. They have a steel case, recessed SB175 connections, and a form factor that worked well for my battery compartment. Also an LED lit on/off switch on the battery that is convenient for maintenance and for my wife to know if there is something happening she doesn’t like she goes for that switch and the propane valve. I’ve had it 3 years now and it’s working fine.

 

[rubberlegs]

Yes, the low temp cutoff worked. Yes, pretty happy with the SOK in most respects. The battery is amazing compared to our previous AGM battery. With our 100AH battery, we can last 3, maybe 4 days with no sun or driving. With our 100W flex solar panel or driving, it's usually above 85% state of charge. I unplug the truck-camper connector few days before going home so it discharges to about 70% for longer-term storage. Note that we don't use a lot of energy compared to some folks here. Just a small fridge, heater, lights, charging electronics. We're usually gone all day, so only the fridge is using energy.

The Bluetooth portion of the BMS in our battery is fine for monitoring... EXCEPT the state of charge. It drifts really badly and is pretty useless. But I hear they've fixed that in the later ones (ours is about 18 months old). I got an inexpensive shunt which takes care of that problem. I think most folks here prefer Victron shunts. I bought the battery from Current Connected which had a really long warranty, even more than SOK at that time. I notice they cost 40% less then what we paid! Oh well, we have enjoyed using it.

I'm not too upset the heater doesn't work, since it was only $10 extra at that time (Current Connected doesn't even have a heated option for the 100AH right now). I've had several email exchanges with the engineer in China and he was pretty responsive. There's an active SOK battery community on Facebook that can answer most questions. I guess I'd get one again, but haven't compared recently to other manufacturers...

 

[Outnabout]

Great. Your energy usage sounds very much like mine. I use a Victron Smartshunt and am happy with the data I get. Basically fridge and heater in cold nights and maybe a phone charge. Thanks again

 

[Outnabout]

Can normal ring connectors be used to hook battery cables on lithium batteries or do they require a special connector?

 

[Jon R]

Can normal ring connectors be used to hook battery cables on lithium batteries or do they require a special connector?

Most batteries have marine style lugs where you would use a suitably sized copper ring crimp connector. My battery uses an Anderson SB175 connector, but that’s less common.

 

[Jon R]

When you select from the lowest priced battery assemblers, make sure the manufacturer is using new cells. According to reviews I’ve seen, some are derating with used cells. Look on youtube to see if Will Prowse has posted a teardown review video of the battery you are considering.

 

[Outnabout]

Thanks. Will Prowse was my next stop.

 

[pods8]

Thanks. Will Prowse was my next stop.

I can save you time if you'd like. SOK, powerurus, litime (certain models) are all good to go per Will and others and in the same ballpark. SOK and powerurus are a step above in terms of build quality if you watch the teardown videos but litime is adequate. With the price point on these now there is little reason to look at the really budget batteries (many without low temp protection and they also bait/switch their build quality internally at times). Not all of the litime batteries have low temp protection so you have to pay attention to that when selecting one.

Some folks don't worry about low temp protection (relying on not camping in the cold or the battery charger sensing for them) but seems foolish for our uses and the minimal cost to have it. Also a battery with bluetooth is handy for testing/trouble shooting to see what is going on with the battery BMS information.

As I mentioned elsewhere my powerurus tested out at full capacity with one pulling 101.5ah and the other 101.8ah. The heated SOK faulty one failed at ~83ah and the adequately performing one didn't pull full capacity but was close at 98-99ah, in both cases the #4 cell was lower than the others on discharge so not sure if there is something funky going on in that specific model or the newer BMS that is causing a bit more draw off #4 and limiting out the battery performance. A single cell falling too low will shut down discharge so it protects that cell.

 

[Outnabout]

Thanks for the information. I agree with you about those 3 brands. I think it is between SOK and Powerusrus. I want the low temp cut off and Bluetooth as you mention. I think I will foregontje heated model as has been pointed out that these are in the living space. If I am going to gone for the day I can just put my heater on low as to keep the battery warm enough to charge.

 

[Jon R]

It’s nice if you can get the chargers into the battery compartment with the battery, so think about shape and dimensions as well.

 

[Outnabout]

I think I am going with SOK 100AH Bluetooth BMS. My question is:
I do not have a Lithium battery charger. I believe charging initially via my solar, with a Victron 100/30 controller, should work as that will be my primary charging. Is there a reason that I would need to initially charge with a lithium battery charger?
Thanks again and I hope the questions aren't getting to be too much.

 

[pods8]

I think I am going with SOK 100AH Bluetooth BMS. My question is:
I do not have a Lithium battery charger. I believe charging initially via my solar, with a Victron 100/30 controller, should work as that will be my primary charging. Is there a reason that I would need to initially charge with a lithium battery charger?
Thanks again and I hope the questions aren't getting to be too much.

Other than it maybe taking a bit longer there is no issue, it'll charge it.

One thing you might want to check are the victron settings. The "lithium" profile on my victron IP22 charger kept going into storage mode. Not sure if the 100/30 has the same issue or not. If so I used these settings for a user defined profile (on both the SOK and powerurus) and it flowed fulls amps until 100% charged.

Victron Blue Smart IP22 12V Battery Charger | Current Connected

Experience efficient and intelligent battery charging with the Victron Blue Smart IP22 Waterproof Charger. Stay connected with built-in Bluetooth.

www.currentconnected.com

 

[Jon R]

The Victron Smart MPPT 100/30 solar charger has adjustable settings that can be set to optimally charge a LiFePO4 battery. It retains those settings unless actively reset. Many of us here are using that as our solar charger for lithium batteries. It’s pretty much set and forget.

 

[Outnabout]

The Victron Smart MPPT 100/30 solar charger has adjustable settings that can be set to optimally charge a LiFePO4 battery. It retains those settings unless actively reset. Many of us here are using that as our solar charger for lithium batteries. It’s pretty much set and forget.

Good features. I have one on the way as well as a battery. Hopefully all will be online next week.

 

[Outnabout]

It’s nice if you can get the chargers into the battery compartment with the battery, so think about shape and dimensions as well.

Nice setup. I have a FWC Grandby with front dinette. The batteries are by the back door. Since I am replacing 2 AGMs I have plenty of room. The SOK is slightly wider but shouldn’t be an issue. I was just out today looking at how I might rearrange things. I won’t have the DCDC, at least at first, so I will have quite a bit of room for the controller and shunt. Although, the new controller is a bit bigger than my old SunSaver.

 

[Jon R]

Nice setup. I have a FWC Grandby with front dinette. The batteries are by the back door. Since I am replacing 2 AGMs I have plenty of room. The SOK is slightly wider but shouldn’t be an issue. I was just out today looking at how I might rearrange things. I won’t have the DCDC, at least at first, so I will have quite a bit of room for the controller and shunt. Although, the new controller is a bit bigger than my old SunSaver.

Mine is a 2021 Grandby front dinette, so probably an identical battery compartment. Let me know if you’d like more pictures or descriptions of what I did.

 

[pods8]

The Victron Smart MPPT 100/30 solar charger has adjustable settings that can be set to optimally charge a LiFePO4 battery. It retains those settings unless actively reset. Many of us here are using that as our solar charger for lithium batteries. It’s pretty much set and forget.

Did you need to adjust the baseline settings as I did with the IP22? It also retains those settings even when unplugged

 

[Outnabout]

Mine is a 2021 Grandby front dinette, so probably an identical battery compartment. Let me know if you’d like more pictures or descriptions of what I did.

Will do. Nice looking rig.

 

[Jon R]

Did you need to adjust the baseline settings as I did with the IP22? It also retains those settings even when unplugged

It’s been a while since I last was changing settings, but it had a set of default settings for lithium, and then you could change them and store a custom setting. I could take a screen shot tomorrow of the settings I’m using if you’d like. I only charge at up to 14.2 volts because I have far more battery capacity than I need most of the time.

The initial setup process is well described in the manual.

 

[Vic Harder]

If I understand correctly, the battery warmer only kicks on when there is charging current present. Makes sense, no? You can happily draw current when your LiFePo4 battery is cold, just not charge. So, why heat it unless you are charging?