One 200 AH lithium battery or two 100 AH?

[John E Davies]

🤔 ... So, disregarding price differences and mounting space, if a guy wanted a 200 AH battery bank (160 AH usable), should he go with one big battery or two smaller ones?

I am thinking that if I had two small ones, and one failed, I could disconnect it and keep camping on the other one.

If I had a single big one and it failed, I would have to buy a cheap Walmart lead-acid junker and use that while the failed one was getting repaired. But all the solar and onboard charging parameters would be wrong for the L/A one.... rats.

If I have two, and one fails five years from now, can I simply add a new one or must they be replaced in sets to keep the capacity equal? Or are they smart enough to compensate for a new one and old one being joined together?

Really, I looked hard about this last question online, and did not find it mentioned..... I am pretty sure that folks with big residential solar banks swap out different aged batteries all the time, how is that working out?

Thanks.

John Davies

Spokane WA

Edited October 4, 2020 by John E Davies

[SeaDawg]

You might want to ask that question on Will Prowse's DIY solar forum.

Adding an additional lithium battery to a bank isn't uncommon. In this thread, I didn't see a response from Will, but several very active members responded.

https://diysolarforum.com/threads/add-another-battery-to-the-bank.4258/

It's still a question of "weakest" battery, I think, but the degradation is so much slower with lifepo4.

Sherry

PS, if we ever change up to lithium, we'll use the biggest two we can fit in the tray. Same reason. 

Also,  one of  the reasons we've never used 6v batteries in our two battery tray. If one goes, we're dead in the water, so to speak.

On the boat, each bank of 6v's has multiple batteries. If something goes wrong, we can cut out one pair. The 2008 Ollie Elite tray only has room for two batteries. 

Sherry 

 

 

[SeaDawg]

And, just for fun, more confusion .

https://diysolarforum.com/threads/incrementally-adding-dc-batteries.186/

[John E Davies]

8 minutes ago, SeaDawg said:

And, just for fun, more confusion .

https://diysolarforum.com/threads/incrementally-adding-dc-batteries.186/

😳 Thanks for the fist link, the second one is beyond me. Since the batteries would be in a camper, not a residence, the number of cycles is not going to be the big factor.

I don’t know yet if I am going this route - my four 6 volt AGMs are being weird and I am going to have them load tested tomorrow. I may end up with just two AGMs for a while. Then I would install two 100AH lithium’s for redundancy. I really don’t like to have a battery failure kill a trip when I can just remove a jumper and reposition a main cable.

This just popped into my head, how do you tell which lithium battery out of two went bad? Does the software (app) tell you by it’s ID or serial number? The concept of smart batteries is hard to grasp. 

Thanks again. 

John Davies

Spokane WA

[SeaDawg]

I agree . 2nd link was way out there. Both, however,  talk about replacing/adding. 

In a camper, unless you are living in it, full cycles are pretty limited.  With lithium, a good bms, as I  understand it, "adds up" partials to full cycles. Even so, degradation is pretty slow with lithium.

I  have two Tesla house batteries, ar home.  Wondering now, how that works? Guess I will look into that, too. 

Good topic.

Sherry 

[GraniteStaters]

Can you use the Zamp 30 amp controller with Lithium?  We are a long way from replacing, but it is good to plan for the future.  

[AndrewK]

Yes you can.  All you have to do is change the type of battery and the controller will adjust it's charging profile.

Andrew

[Overland]

John, if I were buying today, I’d skip the all in one batteries and go with Victron batteries and their separate BMS. They’re still more expensive than Battleborn or LifeBlue, but not as much as when I bought. And the more experience I have with Victron the more I trust them.  Not that I’m unhappy with Battleborn - but as a long term purchase, I think the additional reporting, support, and general peace of mind that you get with the Victrons is worth the extra. 

[John E Davies]

1 hour ago, Overland said:

John, if I were buying today, I’d skip the all in one batteries and go with Victron batteries and their separate BMS. They’re still more expensive than Battleborn or LifeBlue, but not as much as when I bought. And the more experience I have with Victron the more I trust them.  Not that I’m unhappy with Battleborn - but as a long term purchase, I think the additional reporting, support, and general peace of mind that you get with the Victrons is worth the extra. 

Thanks for the advice, but expense is actually a factor, and also system complication. This is NOT what I am after:

 

I want a self contained system with minimal additional changes needed to the Ollie. I already have a Victron SmartBus and like it a LOT, with the exception of the way the trends graph vanishes if the app goes to sleep. (I have not found a setting that will let it run in the background.) Can I fully utilize my SmartBus to keep track of a Battleborne or LiFeBlue “smart” battery bank? Or will that have been a waste of money and effort? I don’t mind using both the battery app and the Victon app if they will cooperate with each other...

Thanks for any and all comments.

John Davies

Spokane WA

Edited October 5, 2020 by John E Davies

[NCeagle]

Interesting.  Sort of a coin toss, but I'd go with a single, larger battery as that is a more future-proof approach in my mind.  You'd have room to grow / add if you wanted with 1 larger capacity battery.  Not so with 2 smaller ones if they fill your tray.  Of course, if you can't add a new battery to an older one to create a set this is a moot point.  🙂    

[Overland]

10 hours ago, John E Davies said:

Thanks for the advice, but expense is actually a factor, and also system complication. This is NOT what I am after

Well you don’t need all that, just the BMS.  It’s Bluetooth and uses the same app as the shunt.  It will give you what you're asking for - individual cell voltages, temps, etc. as well as keep track of charges, errors, etc.  You get Victron quality and support, and a battery small enough that you can fit 600 Ah worth in your battery box with room to spare, and if something happens to the BMS, you don't have to replace the entire battery.  For 200Ah, it would cost about $300 more than the lifeblue total, including the BMS.  Each additional battery is only $100 more.  Well worth it, IMO.  

For me, I wouldn’t even be thinking about LifeBlue.  Battle born, yes, but lifeblue as far as I can tell is a mom and pop business that rebrands Chinese batteries.  I don't mean to disparage them - I say good for them for their initiative, and from what I can tell, I think the batteries are fine.  But, what happens if there's a problem?  A mom and pop is going to have more pressure to deny warranty claims, less time to deal with customers, less expertise for dealing with technical questions or problems, less capacity and financial ability to deal with major problems like a recall, and an uncertain future if something were to happen to one of the owners.  I hope they do well; but for most buyers, these batteries will be the most expensive individual component on their trailer by a factor of two, and for that I’d want expert support and a company that I know is going to be around for a while.

Edited October 5, 2020 by Overland

[John E Davies]

Overland, this is like pulling teeth. I was first confused by the Victron “Not Smart” batteries, I found their actual Smart ones with onboard battery management system. Then I was looking at the size, and Amazon posted the package size, not the actual battery size, so I thought they were way too big for the tray. A little math fixed that brain fart.

 

Victron 12.8/100 Lithium Superpack

330x171x220 mm tall

13” x 6.75” x 8.7” tall

TRAY

21” x 14.1” x 12.5” tall

Is that Amazon one the same as this one?

 

 

So, if I am not confused still, three will fit long side across the Ollie tray. 

The LiFeBlue ones are more squarish, but still will fit three to the tray.

Did I mess up on any of that?

Thanks for your inputs, I and others do appreciate your help. As more early owners of Ollies experience lead acid failures, this will come up again and again. It would be nice if there was a What Fits chart.

John Davies

Spokane WA

[Ray and Susan Huff]

30 minutes ago, John E Davies said:

Overland, this is like pulling teeth. I was first confused by the Victron “Not Smart” batteries, I found their actual Smart ones with onboard battery management system. Then I was looking at the size, and Amazon posted the package size, not the actual battery size, so I thought they were way too big for the tray. A little math fixed that brain fart.

 

Victron 12.8/100 Lithium Superpack

330x171x220 mm tall

13” x 6.75” x 8.7” tall

TRAY

21” x 14.1” x 12.5” tall

Is that Amazon one the same as this one?

 

 

So, if I am not confused still, three will fit long side across the Ollie tray. 

The LiFeBlue ones are more squarish, but still will fit three to the tray.

Did I mess up on any of that?

Thanks for your inputs, I and others do appreciate your help. As more early owners of Ollies experience lead acid failures, this will come up again and again. It would be nice if there was a What Fits chart.

John Davies

Spokane WA

I believe you are correct that 3 lithium batteries will fit on the Elite II tray; that is what Oliver told me when I asked.

 

[John E Davies]

Well, darn it....

 

One completely dead battery, three almost dead. Most likely I contributed to this by leaving the shore power connected most of the time. The battery guy told me that four seasons out of these batteries was pretty good. I told him to take the two worst ones to recycle and I brought back the two less worse ones, to use until I get lithiums. Probably that will be a winter project, I wouldn’t be camping much longer anyway since it will turn cold and damp, and snow by mid-November.

Time to wash it super clean and park it, I guess.

John Davies

Spokane WA

[topgun2]

Bummer!😭

While you knew some of this bad news, having it all hit at the same time can't be much fun.

However, the real bad news is in your next to last sentence.  While it is indeed that time of year for many of us, I really didn't want to face winter yet.

Bill

[AndrewK]

John,

I don’t know if this will help you or not.

We have two 100 amp/hour Battle Born batteries.  We do not have an inverter.

When the nights are mild, in the 50s and no solar, we can go 8 to 10 days without a need to charge.

Nights at or below freezing, 4 to 5 days.

A simple set up, the install was easy and we have room for a third battery mounted sitting on it’s bottom.

No batteries worries, made the expense well worth it for us.

Andrew

Edited October 5, 2020 by AndrewK

[Overland]

Edited - see post below.

Edited October 5, 2020 by Overland

[Ray and Susan Huff]

2 hours ago, topgun2 said:

Bummer!😭

While you knew some of this bad news, having it all hit at the same time can't be much fun.

However, the real bad news is in your next to last sentence.  While it is indeed that time of year for many of us, I really didn't want to face winter yet.

Bill

I have a hard time believing it is almost Winter already?  They say, "Time flies when you're having fun" . . . . . but I don't recall anything fun about 2020 thus far!

[Overland]

OK, here's the dimensions for the Victron Smart batteries.  I knew I hadn't gone crazy.  The chart above is for their older "SuperPack" batteries, which are larger.  

200Ah = 12.6" x 6.0" x 9.3" tall, $2,101.20 from Inverter Supply

100Ah = 12.6" x 6.0" x 7.75" tall, $1,127.95 from Inverter Supply

Weird, yes, but the only difference is apparently an inch and a half in height.  So three of the 200Ah batteries should fit in the tray.  BTW, Victron says do not install them on end, which shouldn't be an issue unless you want more than 600Ah.

Edited October 5, 2020 by Overland

[John E Davies]

Thanks Overland, I appreciate it. I will still go with two 100 ah batteries, but it is good to know that I could add a third, or even triple the total if I felt like spending crazy money ... but I don’t plan on adding solar panel acreage up top, or to even use a portable one. A sun tracking mount for my 360 watt panels , however, might be a go, if they turn out to be indispensable and super cool.

This may have been answered already, does anyone have the Progressive Dynamics part number and cost for the lithium charger unit? Is that something that has to come direct from them?

EDIT. mountainoliver messaged me, this is the unit, at a great price. eTrailer has it for $248 free shipping.

John Davies

Spokane WA

Edited October 5, 2020 by John E Davies

[AndrewK]

John,

Progressive Dynamics 60 Amp PD4060LI, from Battle Born for $272.

Andrew

[John E Davies]

43 minutes ago, AndrewK said:

Progressive Dynamics 60 Amp PD4060LI, from Battle Born for $272.

Thanks, is there any reason to go with the 60 amp over the much cheaper 45 amp version, for a small battery bank? 

John Davies

Spokane WA

[AndrewK]

16 minutes ago, John E Davies said:

Thanks, is there any reason to go with the 60 amp over the much cheaper 45 amp version, for a small battery bank? 

John Davies

Spokane WA

John,

On the few occasions I need to use a generator, to charge the batteries, I want to do it as quickly as possible.  

I hate the sound of a generator.

Andrew

[RnA]

John,

Consider the life time cost of a bank with higher capacity.  This will of course be more money in the short term, but the batteries should last longer because they will be discharged less than a smaller bank. 

As an example; using your battery specification chart above:

400 ah bank  discharged to 80%  = 320 ah for a life of 2500 cycles

Using 320 ah of a 600 ah bank = 53%  for life of ~5000 cycles.  So by increasing your cost by 50%, you get 100% more life out of your batteries.

Either way, that's a lot of cycles.   Assuming you got through 5000 cycles, the lifetime cost of three 200 ah batteries would be cheaper than two 200 ah batteries.  This is very simplified and I'm sure there are other factors.   Something to consider on whatever bank you build, it seems to be better to size for lower depth of discharge.  This has certainly been my experience in sizing lead acid banks.