Lithium Battery Charging System

[CYCLEPATH]

It is time for a new battery in my '04 Lance 921. I am looking at an Interstate battery they sell up the road. But through my research into charging systems/problems, I got to thinking about Lithium batteries. Being a retired cargo pilot, my knowledge about lithium batteries is that if they catch fire, they become quite the spectacle. I was actually surprised they were using them in campers.

My question is, are they worth the price? What do you have to change/do to your charging system to be able to charge one, and is that added expense worth it? I have a PD charger/inverter, and charge wizard now. Is this what you have to change out to be able to charge the lithium battery? And what would take their place? Will the truck alternator charge the Lithium battery? Will the current battery separator need to be changed? It seems a lot easier to just install a new Interstate. I don't do a lot of boondocking, but that could always change in the future. Thank you.

[joeshmoe]

Lithium is a Hassle? LoL it's the same procedure as installing acid batt. Sure, building a raw cell batt. requires a little more effort, but the payoff is far better than lead acid.

Price has dropped considerably for both raw cells and drop in's. You can get an 100Ah LFP for about $350. Probably less if you can catch a sale. That's less than the two 100Ah 160lbs AGM monster I replaced. Effectively the same Ah's.
I paid $400 less than two years ago and they've already begun to degrade. They were well taken care of. Not even used much, really.

Nah. With a 50% usable capacity that begins diminishing immediately at triple the weight vs. roughly 10-15 minimum year life to 80% capacity, even longer for the new K cells, lithium is absolutely less expensive in the long-term.

I do agree. If you're always plugged in, there's no point. But that's not truck camping. That's something else.

[valhalla360]

CYCLEPATH wrote:
Thank you guys for the replies. I went with the Interstate SRM31 battery. We're thinking of getting a fifth wheel here in the not too distant future (and of course keep the Lance). If we do that, I will go the Lithium route with fifth wheel. I need a whole lot of YouTube time before I consider tackling a job like this. Safe camping.

Good choice. If you aren't boondocking a single basic lead-acid is a good choice. You never really need to store that much power as you are either tied to grid power or to the truck alternator. Used in this way, you can expect several years out of a single $100 battery. The small weight savings aren't really worth bothering with. There is pretty much nothing to gain from going lithium.

Where lithium comes into their own is when you want to go off grid and need to store a lot of power.
- A big lead-acid battery bank can weight hundreds of pounds, so trimming 40-50% of the weight can be noticeable.
- Generally lead-acid batteries are limited to around 50% of the rated power before you start damaging them (assuming you start from 100% full). Lithium, you can use around 80%.
- At around 80% full, lead-acid batteries start slowing down in terms of charging. In practice, most people only get them up to 80-90% full when off grid (which is bad for them). Getting to 100% takes many hours. Lithium, you can dump lots of power into them up till nearly full, so fully charging while off grid is much more practical, meaning you have even more available power.

[joeshmoe]

I see you're taking compression pretty serious. I started out compressing, but after looking into it a bunch, it seems compression is of only some minimal benefit to longevity.

With the lesser cycle cells, you'll get some marginal extra life, or with used B or C grade cells. The K cells will last 17 years even if you mildly abuse them. If you really take care of them and constantly keep them in the 60-80% range, they are estimated to last 32 years. And that's without compression.

Not saying compression isnt correct and I know the manufacturers have always recommended it, I just can't see going through the hassle with these new LFK cells.

[3_tons]

“ The first two are working fine except for the SOC I sn’t accurate, I went around and around with Daly but could never get the PC software to work to change their sensitivity, they don’t register a draw below about 3 amps. ”

I’ve found this to be the case with my drop-ins as well, but it’s of no real consequence because the Victron shunt-based meter does the job and more via Bluetooth…Ain’t no substitute for a dedicated shunt based meter…

3 tons

[S_Davis]

StirCrazy wrote:

S Davis wrote:

StirCrazy wrote:

joeshmoe wrote:
The new EVELF280K cells are rated to 6K+ cycles. Building a pack of Four of these cells will provide longer service than any Lead acid. Combined with 3 or 400+ watts of panels, it's a no brainer.

After doing the requisite research and getting past the initial, kinda-steep learning curve of DIY LFPs and now that I've built one, the cost to energy density ratio is clear.

You can keep watering your cells. I'm done with that ****.

when was the K edition released, at 6K cycles going down to 10V from full is a game changer again. double the life at 100% usage and only 600ish us for a set of 4. I like the way they adresses the bolting also. nice set up.

The LF280K have been around for about a year, I purchased the LF280N the previous version last year.

how has your daily BMS been doing, I went with Overkill solar BMS as the dailys were having some issues at the time, or was that just blowen out of proportion like the internet usaly does?

Steve

The first two are working fine except for the SOC I sn’t accurate, I went around and around with Daly but could never get the PC software to work to change their sensitivity, they don’t register a draw below about 3 amps. I am putting together 8 packs so far and have switched to Overkill BMS for the next couple to try them out.

[StirCrazy]

S Davis wrote:

StirCrazy wrote:

joeshmoe wrote:
The new EVELF280K cells are rated to 6K+ cycles. Building a pack of Four of these cells will provide longer service than any Lead acid. Combined with 3 or 400+ watts of panels, it's a no brainer.

After doing the requisite research and getting past the initial, kinda-steep learning curve of DIY LFPs and now that I've built one, the cost to energy density ratio is clear.

You can keep watering your cells. I'm done with that ****.

when was the K edition released, at 6K cycles going down to 10V from full is a game changer again. double the life at 100% usage and only 600ish us for a set of 4. I like the way they adresses the bolting also. nice set up.

The LF280K have been around for about a year, I purchased the LF280N the previous version last year.

how has your daily BMS been doing, I went with Overkill solar BMS as the dailys were having some issues at the time, or was that just blowen out of proportion like the internet usaly does?

Steve

[S_Davis]

StirCrazy wrote:

joeshmoe wrote:
The new EVELF280K cells are rated to 6K+ cycles. Building a pack of Four of these cells will provide longer service than any Lead acid. Combined with 3 or 400+ watts of panels, it's a no brainer.

After doing the requisite research and getting past the initial, kinda-steep learning curve of DIY LFPs and now that I've built one, the cost to energy density ratio is clear.

You can keep watering your cells. I'm done with that ****.

when was the K edition released, at 6K cycles going down to 10V from full is a game changer again. double the life at 100% usage and only 600ish us for a set of 4. I like the way they adresses the bolting also. nice set up.

The LF280K have been around for about a year, I purchased the LF280N the previous version last year.

[StirCrazy]

joeshmoe wrote:
The new EVELF280K cells are rated to 6K+ cycles. Building a pack of Four of these cells will provide longer service than any Lead acid. Combined with 3 or 400+ watts of panels, it's a no brainer.

After doing the requisite research and getting past the initial, kinda-steep learning curve of DIY LFPs and now that I've built one, the cost to energy density ratio is clear.

You can keep watering your cells. I'm done with that ****.

when was the K edition released, at 6K cycles going down to 10V from full is a game changer again. double the life at 100% usage and only 600ish us for a set of 4. I like the way they adresses the bolting also. nice set up.

[towpro]

Camper_Jeff_&_Kelli wrote:
I oversized the solar because we live in the Pacific Northwest and are subject to low winter sun and lots of cloudy, rainy days.

This really does make a big difference. Example, North Carolina coast, with 0 shade. in July 200W was enough for us to boondock, but in September we would need to run the 2K generator every day for an hour so to break even. the following fall we ran 30% more solar in same campsite and everything was OK.

Even in Central FL I was using a 100w panel to keep an RV charged that was parked under a cover. In the winter I would have to tilt the panel to have enough charge but in dead of summer the flat panel was enough.

[joeshmoe]

StirCrazy wrote:

Lwiddis wrote:
"I don't do a lot of boondocking, but that could always change in the future."

I boondocked with wet batteries and now with a Lithium battery. With an adequate solar system recharging either type of battery is not an issue. Sure, my Lithium has more usable power and it recharges faster but those are the only differences I've noticed.

didn't notice the weight and size savings?

Right? He'll also notice a difference over time when money isn't leaving his pocket after just 400-500 lead acid cycles vs multiple thousands of cycles with LFP.

And the person "worried" about whether lithium batteries are safe... That's just silly. Lifepo4 chemistry is super safe and stable. The BMS takes all the worry out of it. You literally need to do nothing except keep it at 20-80% SOC for maximum life. You can even discharge to 0% if need be, so long as its not too quick. Get it charged back up at to at least 20% and you're good.

[joeshmoe]

The new EVELF280K cells are rated to 6K+ cycles. Building a pack of Four of these cells will provide longer service than any Lead acid. Combined with 3 or 400+ watts of panels, it's a no brainer.

After doing the requisite research and getting past the initial, kinda-steep learning curve of DIY LFPs and now that I've built one, the cost to energy density ratio is clear.

You can keep watering your cells. I'm done with that ****.

[Camper_Jeff___K]

First off, Solar panels do not discharge energy into the night.
Solarnight discharge
The back flow diodes and solar controller will prevent it. There is a minor voltage Vbf but it's very small. Also, it doesn't discharge back into the either or sky, it's just a resistance load to the batteries.
Most modern solar electronics have some sort of circuit protection. Even so, since you seem to have power in the day with sun, I would guess your solar charge controller is functio I g to some degree. Since your battery dies quickly, my guess.is.you damaged your batteries BMS. You'll have to do or have done, your own testing. Good luck.

[covered_wagon]

It has to be checked out since a solar controller needs to disconnect the panels at night. If it does not open that connection, between batteries and panels, the panels will suck out all the charging of the batteries back out into the night sky.

You could manually unhook the panels yourself at night and see if the batteries stay charged.

[RBLance820]

Thanks much to covered wagon and Davis for responding. I have checked fuses and all appear to be ok and battery switch is on. Interesting thought that my solar controller could be damaged.

Would anyone know how to check the solar controller. The controller does show a charged battery when it is charged. When I hit the boost function it appears to go into that function.

[S_Davis]

Sounds to me like you blew a fuse or fusable link to the batteries when you hooked them up backwards, I would make sure your main battery switch is on and check the fuses.