Community Forums

Vintage465 · 03-21-2020, 05:45 PM

Quote:

Originally Posted by fisher99

So my question is this: Two 6v batteries rated at 210 ah each gives a total of 210 ah. But you are only supposed to draw a 6v battery down to about 50%, so does that mean that you only have a useable 105 ah (give or take) with two 6v batteries? And thus a single 105 ah Lion Energy battery would give the equivalent usable ah since you can draw it down to zero?

I tend to agree with your theory of the 6's really only being 105ah if used within the suggested discharge. The price dang near makes me a believer. Only issue I'd have is there is no place on my little 20fq to put Lithiums in a temperature controlled environment. And 23 pounds apiece? Wow!

fisher99 · 03-21-2020, 07:51 PM

Quote:

Originally Posted by Vintage465

I tend to agree with your theory of the 6's really only being 105ah if used within the suggested discharge. The price dang near makes me a believer. Only issue I'd have is there is no place on my little 20fq to put Lithiums in a temperature controlled environment. And 23 pounds apiece? Wow!

I'm not sure that the Lion Energy battery needs to be in a temperature controlled environment. According to the specs, the battery can charge at temps between 32 degrees to 113 degrees and discharge at 100% rate between -4 degrees and 131 degrees. Although I guess I have camped at temps below 32 degrees...

brulaz · 03-22-2020, 06:47 AM

I think the temperature issues are real. We currently store our trailer unheated and winterized, and it can definitely get below -4C. Not sure if the batteries need to be brought inside or if just disconnecting them would be sufficient. No problems with the Lead Acids though.

KRum · 03-22-2020, 07:25 AM

As to lithium’s cold weather issue - They should not be charged in below freezing temperatures... They can be discharged and stored in cold temps...

In general I don’t think I would store any battery for the winter in a freezing state.

BillJinOR · 03-22-2020, 07:56 AM

Just to be clear , a adequate built in bms will prevent charging below the low temp minimum protecting the battery .
Storing the battery in lower temps isn’t the problem. A maintenance charger, even if hooked up in those conditions , is blocked. The problem is using the battery in continuous below freezing temps prevents recharging, making them useless once discharged until the temp rises or the batteries are warmed.

okcnewbie · 03-22-2020, 08:01 AM

Quote:

Originally Posted by paul65k

.....Once you have LifePO4 batteries you will wonder how you coud ever live with Lead Acid (including AGM) batteries again

I know you're probably just trolling but;
How do you even know what batteries you have when you turn the lights on,etc?
My 400 amp/hrs of AGM were "set it and forget it". They were still going strong after 6 years when we sold the RV.
Lithium is a waste of money for people that are plugged in 99% of the time

Brad Wilf · 03-22-2020, 06:41 PM

Quote:

Originally Posted by okcnewbie

I know you're probably just trolling but;
How do you even know what batteries you have when you turn the lights on,etc?
My 400 amp/hrs of AGM were "set it and forget it". They were still going strong after 6 years when we sold the RV.
Lithium is a waste of money for people that are plugged in 99% of the time

Or even some of us that 95% dry camp, my 2- 12 v agm’s seem to work just fine. That why we have solar and a genny for back-up.. just in case. I’d rather spend my money on other things.. that I need.

geordi · 03-22-2020, 08:15 PM

The cost-per-watt or cost-per-amp (depending on how you want to think about it) is important.

2 of the GC2 flooded batteries from Costco are $85 each, $170 for 105 usable amps or a total of 1260 watts. Yes, you can take flooded batteries lower than 50%, and the risk there is the lower they go, the faster they want to start growing sulfates on the plates. I tend to think that since it takes time for sulfates to grow (and they don't grow when power is being added back in) that if you have a solar system that starts charging every morning AND you arrive at the morning at about 30% SoC... You've only spent a couple hours at most below 50% so you are minimizing the sulfate issue. How this is in practice, I will have to see.

I have 880 total amps of GC2 batteries right now (8 of these suckers!) and I'm still sorting out the actual power needs when I'm dry camping - partly b/c I haven't looked at my residential fridge's defrost cycle yet to see if I can reduce that. It uses a LOT of power for that heater! As it is right now, I'm sitting on just about a continuous 20 amp draw from my batteries so I SHOULD be well above 50% after a full night... But I'm not convinced that the voltages match up with that from the BMS. Still working out the kinks.

But the cost to duplicate that with Lithium batteries.... I could buy a LOT of generator fuel for that price difference. I can't put anything else in that battery bay, and it isn't like I'm noticing the weight (although it IS heavy to move them!) but the whole coach is 28k lbs already.

BCam · 03-22-2020, 10:32 PM

I'm becoming more and more intrigued with the idea of Lithium Iron Phosphate batteries but, for the last couple of years, for numerous reasons, we haven't been able to use our MH enough to justify the expense. Nor are we going to be using it for the foreseeable future. And, they're only going to get less expensive and better. Maybe someday.

I suppose if I were a full-timer, it would be a no brainer.

fisher99 · 03-23-2020, 11:42 AM

Well, I'm officially a victim of paralysis by analysis. The $699 sale ended yesterday and I still had too many questions to sort out before laying out the cash. I will continue to investigate Li and 6v but it seems more likely that I will end up just replacing my two 12v batteries with two more of the same. It works for us and I don't have to worry about changing out either of my charge controllers (WFCO or solar). Sometimes lazy wins...

egwilly · 03-23-2020, 12:12 PM

Got a product not available warning when I went to the website.

egwilly · 03-23-2020, 12:14 PM

Quote:

Originally Posted by BCam

I'm becoming more and more intrigued with the idea of Lithium Iron Phosphate batteries but, for the last couple of years, for numerous reasons, we haven't been able to use our MH enough to justify the expense. Nor are we going to be using it for the foreseeable future. And, they're only going to get less expensive and better. Maybe someday.

I suppose if I were a full-timer, it would be a no brainer.

Agree. This is the norm for us now......

IdahoBob · 03-23-2020, 05:06 PM

Quote:

Originally Posted by fisher99

Well, I'm officially a victim of paralysis by analysis. The $699 sale ended yesterday and I still had too many questions to sort out before laying out the cash. I will continue to investigate Li and 6v but it seems more likely that I will end up just replacing my two 12v batteries with two more of the same. It works for us and I don't have to worry about changing out either of my charge controllers (WFCO or solar). Sometimes lazy wins...

My eyes have glazed over with this thread. My MSEE degree from 1960 has failed me! But, I have "hi-tech-ed" it to two 6v batteries, in series. That I can still understand!

Good luck!

Bob

fisher99 · 03-23-2020, 05:57 PM

The two 12v batteries that I will be replacing were in the trailer when I bought it 5 1/2 years ago. I figure if I get 5 (or even 4) more years out of a new pair, by then Li will be the price of current 6v (or cheaper) and they'll probably be the size of those Li jumpstart batteries that you can store in your glovebox. Of course then I'll be wanting whatever the new technology is that will have made Li obsolete by then but is just out of my price range. I think I am destined to always be a day late and multiple dollars short...