lithium question

[daily_double]

Can you charge lithium batteries with a regular charger or do I need to buy a special charger?

[Reisender]

BFL13 wrote:

pianotuna wrote:
BFL13,

Given that SiO2 can do 4C continuously, and can be taken to 0% state of charge, why would you suggest that it takes 2 SiO2 to equal 1 LiFePo4?

Didn't mean to say that, if I did. You can use the one LFP or SiO2 with its own inverter to run the MW etc, and use the existing FLA bank for the rest.

100AH is just not enough of any kind of battery bank for a weekend off-grid in the winter. If you don't have the FLA bank you need two LFPs (no mixing--second must also be LFP) or two SiO2s ( might get away with mixing types with them, but not for me thanks) to run it all.

Two FLAs can't run the MW like one of those others can with its high discharge rating, and you still need lots of AH for normal furnace running etc, so that means two of the expensive ones to get just 200AH.

Weight is an issue for these guys with small RVs or they could just have four 6s. That means LFP for the single MW one.

Yep. Weight is definitely an issue for us. But for two reasons. The batteries are located under the bed and slightly behind the axle. The hitch actually gets lighter as you add batteries. Not on a one to one ratio, but it does get lighter. I like to keep the trailer hitch weight at around 10 percent or more on any trailer I’m towing. Nice thing about little trailers is you can literally use a “large person” bathroom scale to accurately measure it. :). Anyway. Adding another set of 6 volt AGM’s wouldn’t be an option for us. If we need more capacity it’s either

1. More solar (but we like to park in the shade so......)
2. A small propane generator to charge the 6 volts once per day for 45 minutes (prefer not doing this but maybe).
3. Switching to a set of LFP 100’s Pricey but doable and the cabinet is ready for them.

Once we start camping in the spring we’ll figure it out. Can’t wait.

[pianotuna]

BFL13,

Thanks.

[BFL13]

pianotuna wrote:
BFL13,

Given that SiO2 can do 4C continuously, and can be taken to 0% state of charge, why would you suggest that it takes 2 SiO2 to equal 1 LiFePo4?

Didn't mean to say that, if I did. You can use the one LFP or SiO2 with its own inverter to run the MW etc, and use the existing FLA bank for the rest.

100AH is just not enough of any kind of battery bank for a weekend off-grid in the winter. If you don't have the FLA bank you need two LFPs (no mixing--second must also be LFP) or two SiO2s ( might get away with mixing types with them, but not for me thanks) to run it all.

Two FLAs can't run the MW like one of those others can with its high discharge rating, and you still need lots of AH for normal furnace running etc, so that means two of the expensive ones to get just 200AH.

Weight is an issue for these guys with small RVs or they could just have four 6s. That means LFP for the single MW one.

[pianotuna]

BFL13,

Given that SiO2 can do 4C continuously, and can be taken to 0% state of charge, why would you suggest that it takes 2 SiO2 to equal 1 LiFePo4?

[BFL13]

You can keep your FLA bank for normal RV work (furnace etc) and also get an LFP for the microwave, kettle, toaster, and TV work.

That way you don't need two LFPs to get enough AH for furnace plus MW, etc. The one LFP can run the MW etc, leaving enough AH on the existing FLA bank for furnace etc.

No wiring changes or converter changes.

The LFP goes anywhere you can stash it inside where it is warm along with its own inverter (needs some air for location) On arrival camping, run an extension cord from the LFP's inverter to outside where you can plug in the shore power cord to the extension cord.

You recharge the FLA bank same as now. You need a portable charger to top up the LFP as required. Or use your converter with jumper cables over to the LFP. put them away after.

I have this sort of set up in the MH for the winter camping off grid. The existing MH set- up is the same as in the Profile, but have moved the two SiO2s (you would use one LFP) from the TC to inside the MH (on the floor behind a chair) with its own inverter connected to that bank.

I run the TV/DVD off that bank to keep those AH off the 6s, which gives them more furnace time. The MW etc can be run off the inverter on the 6s as usual, but I could plug all that into the other inverter.

In your cases, you would do it with the MW's inverter on the LFP and camp as usual off the FLAs for the other loads.

Big lesson I learned with the TC and one 100AH SiO2 (would be the same with one 100AH LFP) is it can run the MW just fine with the high amps, but you still need AH for furnace etc. which means you need 200AH.

The idea here is to save money by keeping your existing FLA bank to do the furnace etc, and now you can do the MW etc with just one LFP. You don't run the big stuff very long, so you don't need a ton of AH--just the high amp discharge the LFP can provide.

Note in this scenario the converter is not on the same bank as the inverter so no loop issues plugging into the shore power cable.

[Reisender]

Ivylog wrote:
Why would you replace 2 new AGM batteries (good for 5+ years) with overpriced Lithiums…in 5 years the prices will be even lower. Assuming the cells I bought finally arrive, building a LifePo4 battery for $1/AH makes them price comparative with AGMs but 3X the cycles.

Yep. And that’s why We are going to live with the 6 volt AGM’s for awhile and see how it goes. I will jump through a few hoops to make it work if I can, but camping under trees kinda takes the solar solution off the table. We usually move every few days but we don’t go usually very far before we are in our next camping and hiking spot so on the road charging may not be very effective. So if it doesn’t work with the 2 X 6 volt AGM’s it’s either a little portable propane inverter generator or upgrade to a couple of 31 LFP’s. The trailer (and SUV) don’t arrive until early 2022 so until then it’s kinda watch and learn what others are doing.

Cheers.

[Ivylog]

Why would you replace 2 new AGM batteries (good for 5+ years) with overpriced Lithiums…in 5 years the prices will be even lower. Assuming the cells I bought finally arrive, building a LifePo4 battery for $1/AH makes them price comparative with AGMs but 3X the cycles.

[StirCrazy]

Reisender wrote:

StirCrazy wrote:

Reisender wrote:

StirCrazy wrote:

Reisender wrote:

StirCrazy wrote:

S Davis wrote:


EVE LifeP04 cells are 10% to 90% for 3500 cycles, they should still have 80% capacity at that point. If so these should outlast me.

I think your missreading that a bit.. the industry standard is that the cycles they list are based off a 100% usage. they recomend 10-90% use range and that will extend your cycle life possibly up to 5000-7000 cycles, before you reach that 80% threshhold. then that 80% could be maintained for another 10 years or longer, if you treat them good.

Steve

Yep. This is why Hertz rent a car is buying 100,000 base models of an EV that uses LFP batteries. An expected battery lifetime of a million kilometres vice other chemistries. You can pretty much run LFP to zero frequently without as much worry of damage. 10 to 90 is much better though. The sacrifice is they are heavier and performance suffers a bit from the higher end models.

We are kicking around the idea of putting something like a battle born in our new little trailer that comes with 2 x 6 volt AGM’s. The cheap skate in me says live with the AGM’s and wait a few more years and the price delta to come down. Guess we’ll see.

haha AGM, up here, are more expensive that some of the new LFP on the market. and if you can hook up a four 6V battery sety up in your camper you can build your own batter setup with prismatic LFP cells which is so much cheeper. Battle born is way over priced now, there competators in the market and I believe they all agreeded on a price trying to hold on to the prices they set when they were only one of 3 range.

Steve

Yep, they are pricey. But am I right? You seem to have a good handle on this. The trailer comes from the factory with 2 x 6!volt AGMs. Would an LFP 31 not be giving up a bit as far as useable amp hours? They are in a heated area so that’s not an issue.

you could be depends on the exact size of the 6V agms, but we can assume say 180ah??? then a 100 AH LFP would give you the same amount aproximatly of usable , but in a pinch with the 6V you could go down to 20% which means in a emergency you would hve a 144AH capacity. I dont like to size LFP to use the "equivalant" usable AH I like to take advantage of the size and weight and get more AH in a lighter and smaller package. so for me I would realy go with two of thoes batteries, run them nice and take that cycle life through the roof and when you need it you will have a total of 200AH for use in an emergency, but you'll probably never buy another set of batteries in your life.

Steve

Thanks Steve. That’s probably the way we’ll go. Although we’ll probably give it a go with the 2 AGM’s for the first season. This little trailer has hydronic heat and hot water so no big furnace fan load. I’m told by other T@B 400 owners that the 2 6 volts and solar panel are good for at least a few days of dry camping. But I know where we like to camp and quite often there is shade involved soooooo.... ,, the solar panel may be of limited use.

The reality is the tow vehicle is a Tesla with an 82 KWH battery so it will never be a crisis as we can just tap into that reserve via the 16 amp accessory port. We did some tests to insure this would work. But it’s extremely inefficient as it uses double conversion from DC to AC back to DC again. As well the car has to be “on” which wastes a couple watts right out of the gate.

A friend of ours bought a champion 2500 watt propane (dual fuel) super quiet genny from Costco. We are going to look at it and see if it would be handy for extended dry camping. We have a bigger champion for backup home power and are really happy with it but too big to drag with us. The little one is around 50 pounds so not bad. But we prefer not to have to drag a genny with us. Or at least not on a regular basis. But as you know, your and our area has a ton of great non serviced camp sites close to us. (We are in Vernon). It will probably be handy to have a little propane genny.

Cheers and thanks for the info.

I have two deep cycles in my Camper with one 24V, 325 watt solar panel, using the furnace I am go 3 to 4 days with no sun and forever if I get sun (I am in Kamloops) the reason I want to do LFP in the camper isnt for the normal camping , but rather so I could install a microwave or somthing like that and for camping in the winter where the furnace draw will be higher than say octoberish. also in the camoer weight and size are key issues and they would reduce both of thoes a lot. my 6V's work but you realy need 4 to be able to rent higher curents deicently. thats the set up I have in the 5th wheel, it is going LFP to reduce the weight by 246lbs in the front, get back a bunch of my storage space and take my usable AH from 235 to 600ah.

Steve

[Reisender]

StirCrazy wrote:

Reisender wrote:

StirCrazy wrote:

Reisender wrote:

StirCrazy wrote:

S Davis wrote:


EVE LifeP04 cells are 10% to 90% for 3500 cycles, they should still have 80% capacity at that point. If so these should outlast me.

I think your missreading that a bit.. the industry standard is that the cycles they list are based off a 100% usage. they recomend 10-90% use range and that will extend your cycle life possibly up to 5000-7000 cycles, before you reach that 80% threshhold. then that 80% could be maintained for another 10 years or longer, if you treat them good.

Steve

Yep. This is why Hertz rent a car is buying 100,000 base models of an EV that uses LFP batteries. An expected battery lifetime of a million kilometres vice other chemistries. You can pretty much run LFP to zero frequently without as much worry of damage. 10 to 90 is much better though. The sacrifice is they are heavier and performance suffers a bit from the higher end models.

We are kicking around the idea of putting something like a battle born in our new little trailer that comes with 2 x 6 volt AGM’s. The cheap skate in me says live with the AGM’s and wait a few more years and the price delta to come down. Guess we’ll see.

haha AGM, up here, are more expensive that some of the new LFP on the market. and if you can hook up a four 6V battery sety up in your camper you can build your own batter setup with prismatic LFP cells which is so much cheeper. Battle born is way over priced now, there competators in the market and I believe they all agreeded on a price trying to hold on to the prices they set when they were only one of 3 range.

Steve

Yep, they are pricey. But am I right? You seem to have a good handle on this. The trailer comes from the factory with 2 x 6!volt AGMs. Would an LFP 31 not be giving up a bit as far as useable amp hours? They are in a heated area so that’s not an issue.

you could be depends on the exact size of the 6V agms, but we can assume say 180ah??? then a 100 AH LFP would give you the same amount aproximatly of usable , but in a pinch with the 6V you could go down to 20% which means in a emergency you would hve a 144AH capacity. I dont like to size LFP to use the "equivalant" usable AH I like to take advantage of the size and weight and get more AH in a lighter and smaller package. so for me I would realy go with two of thoes batteries, run them nice and take that cycle life through the roof and when you need it you will have a total of 200AH for use in an emergency, but you'll probably never buy another set of batteries in your life.

Steve

Thanks Steve. That’s probably the way we’ll go. Although we’ll probably give it a go with the 2 AGM’s for the first season. This little trailer has hydronic heat and hot water so no big furnace fan load. I’m told by other T@B 400 owners that the 2 6 volts and solar panel are good for at least a few days of dry camping. But I know where we like to camp and quite often there is shade involved soooooo.... ,, the solar panel may be of limited use.

The reality is the tow vehicle is a Tesla with an 82 KWH battery so it will never be a crisis as we can just tap into that reserve via the 16 amp accessory port. We did some tests to insure this would work. But it’s extremely inefficient as it uses double conversion from DC to AC back to DC again. As well the car has to be “on” which wastes a couple watts right out of the gate.

A friend of ours bought a champion 2500 watt propane (dual fuel) super quiet genny from Costco. We are going to look at it and see if it would be handy for extended dry camping. We have a bigger champion for backup home power and are really happy with it but too big to drag with us. The little one is around 50 pounds so not bad. But we prefer not to have to drag a genny with us. Or at least not on a regular basis. But as you know, your and our area has a ton of great non serviced camp sites close to us. (We are in Vernon). It will probably be handy to have a little propane genny.

Cheers and thanks for the info.

[AllegroD]

No. Just any charger could cause damage. You need to see the mfgr recommendations. Most require a charger that can be set to charge no higher than 14.4.

[StirCrazy]

Reisender wrote:

StirCrazy wrote:

Reisender wrote:

StirCrazy wrote:

S Davis wrote:


EVE LifeP04 cells are 10% to 90% for 3500 cycles, they should still have 80% capacity at that point. If so these should outlast me.

I think your missreading that a bit.. the industry standard is that the cycles they list are based off a 100% usage. they recomend 10-90% use range and that will extend your cycle life possibly up to 5000-7000 cycles, before you reach that 80% threshhold. then that 80% could be maintained for another 10 years or longer, if you treat them good.

Steve

Yep. This is why Hertz rent a car is buying 100,000 base models of an EV that uses LFP batteries. An expected battery lifetime of a million kilometres vice other chemistries. You can pretty much run LFP to zero frequently without as much worry of damage. 10 to 90 is much better though. The sacrifice is they are heavier and performance suffers a bit from the higher end models.

We are kicking around the idea of putting something like a battle born in our new little trailer that comes with 2 x 6 volt AGM’s. The cheap skate in me says live with the AGM’s and wait a few more years and the price delta to come down. Guess we’ll see.

haha AGM, up here, are more expensive that some of the new LFP on the market. and if you can hook up a four 6V battery sety up in your camper you can build your own batter setup with prismatic LFP cells which is so much cheeper. Battle born is way over priced now, there competators in the market and I believe they all agreeded on a price trying to hold on to the prices they set when they were only one of 3 range.

Steve

Yep, they are pricey. But am I right? You seem to have a good handle on this. The trailer comes from the factory with 2 x 6!volt AGMs. Would an LFP 31 not be giving up a bit as far as useable amp hours? They are in a heated area so that’s not an issue.

you could be depends on the exact size of the 6V agms, but we can assume say 180ah??? then a 100 AH LFP would give you the same amount aproximatly of usable , but in a pinch with the 6V you could go down to 20% which means in a emergency you would hve a 144AH capacity. I dont like to size LFP to use the "equivalant" usable AH I like to take advantage of the size and weight and get more AH in a lighter and smaller package. so for me I would realy go with two of thoes batteries, run them nice and take that cycle life through the roof and when you need it you will have a total of 200AH for use in an emergency, but you'll probably never buy another set of batteries in your life.

Steve

[time2roll]

3 tons wrote:
Lots of talk about achieving ‘max cycles’ (most anything can ‘and should’ be optimized, eh?), but from my own myopic perspective, with soooo many available charge cycles, I don’t bother much engaging in all that might worry - Were I to lose say 10% of 5,000 LFP charge cycles (due to my own reckless inattentiveness?? lol), I’m still quite happy (in exchange) to enjoy the ‘real-use’ benefits and longevity of LFP…One way or another just about everything in this universe comes with an expiration date, eh - In fact, I’ve yet to learn of anything that gets a waiver 🙂 !! JMHO

3 tons

Yes the whole "maximize life cycles" for LFP is one more hangover from the old lead-acid days because cycles were so few back then.

[3_tons]

Lots of talk about achieving ‘max cycles’ (most anything can ‘and should’ be optimized, eh?), but from my own myopic perspective, with soooo many available charge cycles, I don’t bother much engaging in all that might worry - Were I to lose say 10% of 5,000 LFP charge cycles (due to my own reckless inattentiveness?? lol), I’m still quite happy (in exchange) to enjoy the ‘real-use’ benefits and longevity of LFP…One way or another just about everything in this universe comes with an expiration date, eh - In fact, I’ve yet to learn of anything that gets a waiver 🙂 !! JMHO

3 tons

[pianotuna]

HMS Beagle wrote:
All manufactured EVs use some other lithium chemistry, typically lithium cobalt. LFP (short for Lithium Ferris Phosphate) are less energy dense, but much more fire resistant. I'm just pointing this out because many people will say the lithium batteries are unsafe and burn, just look at the Tesla and Boeing fires, without understanding the difference.

If you google ice fires--there were 150,000 in USA last year. The fire problem is over blown, and in my opinion, a negative advertising campaign.

The Bolt batteries were defective from the factory that made them. They are replacing them all.

From a seller of LI: https://www.solacity.com/how-to-keep-lifepo4-lithium-ion-batteries-happy/

[S_Davis]

StirCrazy wrote:

S Davis wrote:


EVE LifeP04 cells are 10% to 90% for 3500 cycles, they should still have 80% capacity at that point. If so these should outlast me.

I think your missreading that a bit.. the industry standard is that the cycles they list are based off a 100% usage. they recomend 10-90% use range and that will extend your cycle life possibly up to 5000-7000 cycles, before you reach that 80% threshhold. then that 80% could be maintained for another 10 years or longer, if you treat them good.

Steve

Yes you are correct, that is their recommendation for max cycles. Pulled this from the spec sheet, they consider a cycle from fully charged to 2.5 volt cut off.

A fte r sta nda rd char ged and 30 mins res t, discharge to 2.5V cutoff with the current of 1.0C(A) at (25±2) °C, and then start the next cycle, end with the capacity decrease to 80%
of the initial capacity. The number of cycles is defined as the cycle life of the battery.