4x100ah lithium vs 2x200ah lithium

[DonkeyFluffer]

I'm planning my upgrade to lithium. The 200ah lithium, while bigger in physical size, should fit in my battery compartment, and overall will cost a little less than 4 of the 100ah batteries. I'll need less battery cables also. Other than capacity, specs are the same. They both have 100ah peak, with short duration higher peak ah.

The brand currently in the lead for me is Weize. It does come in 100 and 200ah versions. It does have low temperature cutoff. Will Prowse really likes it. I'm not buying Battleborn because I don't believe they still are hundreds of $ better.

I'm really just wondering if getting 2 200ah batteries is a bad idea in comparison to buying 4 100ah batteries.

Weize currently only let's you buy 2 of their 100ah batteries but the 200ah batteries are basically unlimited. I don't know why.

ALTERNATIVELY;

Chins sells 100 and 200ah versions that are heated and have Bluetooth built in. Will Prowse likes them also. They will cost more than the Weize and I'm unsure if heaters are necessary or will low temp protection suffice.

FINALLY, there's SOK. Which may cause pain when buying, but could be the right answer for brand.

REGARDLESS; My primary question remains: 2x200ah or 4x100ah and why?

[craigav]

I would consider what your maximum amp draw will be. Most 100 and 200ah batteries appear to have a max output of 100amps. So if that is the case with the batteries you are looking at the difference would be a max current of 400a vs 200a which may be important to you, maybe not. Depends on your setup and inverter. ~CA

[DonkeyFluffer]

Originally Posted by craigav

I would consider what your maximum amp draw will be. Most 100 and 200ah batteries appear to have a max output of 100amps. So if that is the case with the batteries you are looking at the difference would be a max current of 400a vs 200a which may be important to you, maybe not. Depends on your setup and inverter. ~CA

It's a question I really can't answer with my current knowledge. Not planning to go whole house, just keeping the inverter as is. Not going to try to run the AC's, even though I have Soft Start. Will run coffee pot and maybe microwave, not at same time. All the batteries I'm considering have 100 amp max with very short (3 seconds) 200 amp peaks, even the SOK. So I presume I'm not asking to much of them.

[DonkeyFluffer]

My other dilemma is figuring out the connections in the battery tray. I did convert a previous motorhome from 1x12 volt to 2x6volt, parallel to series in effect, and I do understand that basic cabling. But inside my tray I have at least two negative leads leaving the house batteries, from different negative posts, going to never never land in the chassis and no idea what they are. All diagrams I look up only show one positive and one negative coming from the RV chassis.

The BIM is another issue. What I believe is the one in mine doesn't have all the connections of the one I need to replace it with. (LiBIM 225) see photo. So replacing that will involve some major head scratching. I have installed a DC to DC in my Gladiator before, but as Rustynuts pointed out to me the LiBIM has advantages that I want to keep.

The converter will change its charging profile to lithium easy enough, I found that switch, and adding the two additional 190 watt panels to the roof is well within my previous experience level.

In two weeks, my four week RV trip will end. House batteries are shot and I doubt Entegra/Jayco will buy me new ones though I'm sure I took good care of them in the 6 months I've had them. They were always plugged in and I didn't discover how bad they were until this trip and how quickly they'd would be at 11.5 (3 hours with only the absorption fridge running).

Replacing them with 4 more 6 volt AGM batteries will be almost $1000. I can get 400ah of lithium for about $2000 all in, so that's the smarter path for me. If I pay someone, that value goes away, so I'm going to do my best to DIY it with help from you folks and whatever other sources I can gain. My searches on here haven't been that successful, but it could be Tapatalk as I don't have a computer.

Anyway, thanks in advance.

Jim

[DonBr]

Amps are cumulative in parallel. 4x100 is 400. 2x100 is 200. The only way to match the 4x100 with 200A batteries is to get 200s with 200A BMS instead of 100A BMS. Usually the cost goes up to, or above, the 4x100 cost.

[Rustynuts]

Originally Posted by DonkeyFluffer

My other dilemma is figuring out the connections in the battery tray. I did convert a previous motorhome from 1x12 volt to 2x6volt, parallel to series in effect, and I do understand that basic cabling. But inside my tray I have at least two negative leads leaving the house batteries, from different negative posts, going to never never land in the chassis and no idea what they are. All diagrams I look up only show one positive and one negative coming from the RV chassis.

The BIM is another issue. What I believe is the one in mine doesn't have all the connections of the one I need to replace it with. (LiBIM 225) see photo. So replacing that will involve some major head scratching

On mine, one ground wire connects from the battery to the Freightliner chassis frame and one wire connect from the battery to the Jayco body framework that is welded to the Freightliner chassis, it’s basically to help bond the two together.

The box that you show in the picture is the Freightliner chassis power junction box and you shouldn’t be touching anything in there at all. You should have a carpeted box next to that Freightliner junction box, your BIM is inside this box along with several other components like breakers and disconnect solenoid. The LiBIM (green label) will look the same and have the same connections as the BIM (white label) you have now, it’s a direct swap.

[DonkeyFluffer]

Originally Posted by Rustynuts

On mine, one ground wire connects from the battery to the Freightliner chassis frame and one wire connect from the battery to the Jayco body framework that is welded to the Freightliner chassis, it’s basically to help bond the two together.

The box that you show in the picture is the Freightliner chassis power junction box and you shouldn’t be touching anything in there at all. You should have a carpeted box next to that Freightliner junction box, your BIM is inside this box along with several other components like breakers and disconnect solenoid. The LiBIM (green label) will look the same and have the same connections as the BIM (white label) you have now, it’s a direct swap.

Phew! Saved me again Rustynuts. I'll go to the carpeted box. And thank you also on the two negative leads (grounds), I'll mimic as best i can.

[DonkeyFluffer]

Originally Posted by DonBr

Amps are cumulative in parallel. 4x100 is 400. 2x100 is 200. The only way to match the 4x100 with 200A batteries is to get 200s with 200A BMS instead of 100A BMS. Usually the cost goes up to, or above, the 4x100 cost.

So, 2x200ah is not 400 because of the BMS limitations? Ok, 4x100 batteries fit with no concerns and will only run me another $60 or so. But the SOK 100ah are out. They aren't available and haven't been for a long time, only the 206ah are readily available

[craigav]

Originally Posted by DonkeyFluffer

So, 2x200ah is not 400 because of the BMS limitations? Ok, 4x100 batteries fit with no concerns and will only run me another $60 or so. But the SOK 100ah are out. They aren't available and haven't been for a long time, only the 206ah are readily available

2x200ah is 400ah just like 4x100ah. The difference is in regards to how much current maximum can you pull at any given moment. Most 200ah LifePo4 batteries only allow for 100 amps to be pulled from the battery at any given time (BMS limits), however you still have 200ah and could pull 10 amps for 20 hours (10a x 20hrs=200ah).

Only inverters larger than ~2000w would\could pull more than 200 amps at any given moment and for such an inverter it would be better to have the 4 batteries with capabilities of 100a each to provide for such a load. On the same hand, if you were pulling say 10amps (~1200w) then both 2x200 or 4x100 options would provide for the same amount of battery ah capacity. ~CA

[DonkeyFluffer]

Originally Posted by craigav

2x200ah is 400ah just like 4x100ah. The difference is in regards to how much current maximum can you pull at any given moment. Most 200ah LifePo4 batteries only allow for 100 amps to be pulled from the battery at any given time (BMS limits), however you still have 200ah and could pull 10 amps for 20 hours (10a x 20hrs=200ah).



Only inverters larger than ~2000w would\could pull more than 200 amps at any given moment and for such an inverter it would be better to have the 4 batteries with capabilities of 100a each to provide for such a load. On the same hand, if you were pulling say 10amps (~1200w) then both 2x200 or 4x100 options would provide for the same amount of battery ah capacity. ~CA

That's makes sense. And my inverter is only 2000 watts. Two of the SOK 200ah batteries (actually 206) fit in the battery tray and are available now. The 100ah are simply not available and haven't been.

Does anyone have experience with Weize or Chins. Weize has low temp cutoff and the version of Chins I'd be getting, above their base model, has quality heaters and bluetooth.Bluetooth.

Will Prowse doesn't think heaters are needed in most cases, but low temp cutoff is a must. I could get 4x100ah Weize batteries for about $1560+tax. The 4x100 Chins with heaters would be $2183, so I'm leaning toward Weize at the moment.

[craigav]

It is my opinion that low temp cutoff's are not needed by most (or many may be a better word) RV'rs. The reason is that you don't need to cut them off for low temps when discharging the battery(s), only when charging them, and for me, when I have power to charge them I also have power to provide a bit of heat before I charge them. I realize that may not be the case for others though. ~CA

[DonkeyFluffer]

Originally Posted by craigav

It is my opinion that low temp cutoff's are not needed by most (or many may be a better word) RV'rs. The reason is that you don't need to cut them off for low temps when using the battery(s), only when charging them, and for me, when I have power to charge them I also have power to provide a bit of heat before I charge them. I realize that may not be the case for others though. ~CA

I can see your point, but I leave my RV plugged in year round, have for 20 years. I know my batteries are pretty much topped off all the time, but I know Murphy well, and Murphy will find a way to start charging my new lithiums on a 15° day. If I was moving them inside the RV, I'd gamble on not having low temp cutoff, but I'm going to keep them in the slideout tray. I also know I could leave the RV unplugged, especially with lithiums, and only top them off every few weeks, but I'm frequently out there all year, fiddling and molding, plus we run dehumidifiers and/or fans to keep it dry inside.

[Jeepin Jason]

What do you think caused the house batteries to go bad? We have had our unit for 6 months now. We have not plugged it in during storage (over 5 months of ownership, it has been at various dealers for service so the solar panels have been keeping them charged up with the invertor off so that nothing else in the unit is powered up. On our trip last week, I was fairly impressed with the battery power and ability to keep a charge.

[DonkeyFluffer]

Not sure. Didn't do a load test on them when I took delivery. Always had a surface charge around 12.5 to 12.7. Keep it plugged in at the house and the one week we used it prior to this one month trip. Solar works but too shady at the house. So this trip we've boondocked several times and they're dead within a few (3 - 4) hours. It's cool up here in Maine, so we've only used the USB fans and the absorption fridge hardly has to work at all.

If I had to guess, there was probably a battery out of the 4 that was bad from the start or shortly thereafter and it ruined the others. Lithium was my planned winter upgrade anyway, now I've moved that up and I'm not letting the bad batts bother me while we enjoy this trip.

I kept the flooded lead acid batteries in my last unit going for 5 years before I upgraded to AGM, and have had similar success with prior motorhomes, so I think I know how to take care of the older tech batteries. Lithiums will be a learning curve but I've been running a cheap Chinese lithium as a second battery on my Gladiator for almost two years with a DC to dc and 200 watts of solar and haven't ruined anything. See pic. Just seems like replacing the AGM's feels more intimidating than doing it from scratch in the Jeep.

[TomC_AZ]

Where on the rig would the batteries be installed?

Low temp cutoff is only for charging it does not impact or effect discharging (using) of the battery. That is a much much lower temp. Also it’s the battery internal temp that would need to hit the cutoff temp, not just outside temp.

If the batteries are installed in a pass through or internal storage location then the low temp would be good to have but heating pads would prob be a waste of money.

Chins and Ampiertime both make a 200AH Plus model that will do 200amps discharge.

It really comes down to a few things, will they fit the location, will they provide needed power for now and future (these will/should last years). Lastly will they fit into the wanted financial plan.

One other thing to look at is your charger and making sure it is lithium compatible as keeping it plugged in 24/7 may become an issue if it’s not.

[DonkeyFluffer]

They would go in the sliding battery tray the original AGM batteries are in now. 15° is about as cold as I've seen here, with the norm being 25° to 40° at night in January.

The converter has a lithium setting.

I do know they'll work when it's below freezing but shouldn't charge below freezing. That's why I do insist on the low temp cutoff.

My 4 week RV trip to Maine ends tomorrow and I'll look at those Chins 200ah batteries you mentioned. Weize says their 100ah have a 200ah peak and have agreed to sell me 4 instead of just 2. That's $1556 for all four 100ah batteries (includes $40 in discounts), giving me 400ah with low temp cutoff.

4 of the Chins 100ah, with heaters and bluetooth, would total $1959 with discounts. So I'll probably save the $403 and go with the Weize.