Are lithium batteries worth the cost?
I can carry two group 29s in my AF1150.
Are they worth it?
Are they worth it?
Forum Discussion
73 Replies
- I would far prefer 14.3 with short absorption and drop to 13.3 volts for immediate storage or continuous normal use. Holding LFP at 100% is again applying lead-acid charging parameters to a different battery. Change is hard.
Battleborn wrote:
If you are storing your rv and wish to have it plugged in, we would recommend a float voltage of 13.6 volts. If you have a higher voltage applied in float(such as 14.6) then we would recommend that this be no longer than 3 weeks at a time.BFL13 wrote:
Durb wrote:
I installed a 100AH Battle Born battery and Progressive Dynamics Lithium Convertor in my trailer. No maintenance, no removing the battery during the winter, no battery tender during the off season. I don't obsess about SOC and all the other stuff in this thread. I just ignore the battery and expect to do so for the next ten years. So far, the battery meets all my needs. So, for me, the lithium conversion was worth it.
If that means you are leaving it plugged in for long periods of time doing 14.4-14.6 after it has been fully charged, AFAIK, that would be against Battle Born's guidelines.
Some say to isolate that PD Li converter from the LFPs soon after the batts are fully charged. You still want the converter on in the RV.
That PD Li converter might have been a big mistake in their rush to have something to sell with "Li" written on it.
Agreed, I have no idea why progressive dynamics thought a constant 14.6V output would be a good fit for a lithium battery. You want to shut this off after the battery is charged, or better yet just use their regular converter, which is better suited to lithium.Durb wrote:
I installed a 100AH Battle Born battery and Progressive Dynamics Lithium Convertor in my trailer. No maintenance, no removing the battery during the winter, no battery tender during the off season. I don't obsess about SOC and all the other stuff in this thread. I just ignore the battery and expect to do so for the next ten years. So far, the battery meets all my needs. So, for me, the lithium conversion was worth it.
If that means you are leaving it plugged in for long periods of time doing 14.4-14.6 after it has been fully charged, AFAIK, that would be against Battle Born's guidelines.
Some say to isolate that PD Li converter from the LFPs soon after the batts are fully charged. You still want the converter on in the RV.
That PD Li converter might have been a big mistake in their rush to have something to sell with "Li" written on it.Durb wrote:
I installed a 100AH Battle Born battery and Progressive Dynamics Lithium Convertor in my trailer. No maintenance, no removing the battery during the winter, no battery tender during the off season. I don't obsess about SOC and all the other stuff in this thread. I just ignore the battery and expect to do so for the next ten years. So far, the battery meets all my needs. So, for me, the lithium conversion was worth it.
That's pretty much how I feel also..While there are alot of things about the lifepo4 that interest me to totally understand it,none of it really matters in my day to day use..
It is just another battery except it can be drawn down 100% and it is totally lighter/charges way faster and does not need a 100% charge/ and the life cycles far exceed the others with caution towards charging below 32C..What's not to like..- I installed a 100AH Battle Born battery and Progressive Dynamics Lithium Convertor in my trailer. No maintenance, no removing the battery during the winter, no battery tender during the off season. I don't obsess about SOC and all the other stuff in this thread. I just ignore the battery and expect to do so for the next ten years. So far, the battery meets all my needs. So, for me, the lithium conversion was worth it.
Dodgemahal wrote:
... the lithium battery will absorb a lot of amps if you offer it up ...
Technically, voltage is pushed at the battery, and based on how many volts successfully reach the battery, the battery decides how many amps it wants to pull (at that voltage).
As hinted at above, Victron's burning-up alternator video is misleading in that it doesn't model in voltage drop, not to mention their pully gearing did not reflect what is typically installed in a truck, and they were running the alternator much slower than a truck at idle.
Lead-acid batteries typically want ~12.6VDC before they start pulling any current. Battery University says 12.6VDC +/- 0.3VDC.
LiFePO4 batteries typically want ~13.6VDC before they start pulling any current.
Factoring in voltage drop...
At ~13.6VDC from my 45A-capable Progressive Dynamics converter/charger with very short 4AWG wiring, my 100Ah x 2 BattleBorns at 50% SOC choose to pull ~4A total. At 13.6VDC, their thirst for current is minimal.
Assuming ~50 feet (one way) of 10AWG wire between your truck alternator thru the 7-pin to the battery, and an alternator putting out 14.4VDC, by definition you can only put a ~8 amp load on the wire before the voltage drops to 13.6VDC, which put another way means you can hook any number of LiFePO4s to such a 7-pin setup and you won't exceed ~8 amps of pull. No wires fry, no alternator burns out, etc.
Here is a link to the voltage drop calculation.
Assuming ~35 feet (one way) of 4AWG thru say Anderson connectors, a 46 amp load will drop the voltage to 13.6VDC, hence you won't exceed 46A of pull no matter how many LiFePO4 you hook up and how massive your alternator is.
Here is the updated calculation.
All that said to counter the myth that LiFePO4s always burn up wires and alternators if direct wired (unless the wires are really big and short!), DC-to-DC converters do so many valuable things, including countering voltage drop.
--tgStirCrazy wrote:
Dodgemahal wrote:
Not putting a DC to DC charger in the system carries the risk of two things. Discharged lithiums can pull max current from your (non smart) alternator which will burn it up and possibly cause a fire. Ending up on the side of the road is a big possibility.
Lets clear this one up before it starts spreading as fact.
The only way this is going to happen is is some one took the fuse out of your charging line for your 7 way. Or if some person who didnt have a clue installed there own because it want a factory option and didnt put a fuse in.
I think most of this stems from the youtub video of a guy hooking a li pack directly to an altnator with large wires and started it up using an electric motor. no fuse now voltage loss and yes it did start stuf burning.
having said that I still would encourage the use of a LFP compatable DC to DC charger and proper wiring to provide the LFP battery its best charging.
Steve
Steve
Well you just reiterated what I was mentioning. The proper way to charge Lithiums (with the truck charging system)is with a DC to DC charger and not unregulated with a smart or dumb alternator. Because the lithium battery will absorb a lot of amps if you offer it up. Not sure what you cleared up though. Facts are what we both stated. So thank you. :)FWC wrote:
Got it. Appreciate you taking the time to clarify everything, FWC. Tried to look at the article in your link, but it was asking for registration info and a subscription fee. The article looked like it addressed my query perfectly.
I think the actual test data in the paper is probably more telling. There they charge/discharge LiFePO4 cells at 1C, 1000 times at various temperatures. Even after brutal test like this, the battery that was cycled at -5C had only slightly worse degradation than the room temperature batteries. To me that makes it pretty clear that an occasional charge cycle at -5C (or even lower) at a less than 1C rate of charge is not something to be worried about. Cycling at very high temperatures was actually far worse for the battery.
It is up to the user to decide what their requirements are, but for my use I am never going to need 2000+ 100% DOD cycles out of my batteries. In a good year, I am at about 100 nights of use, and most of those are at < 50% DOD, so even if I only get 20% of the rated cycles from my LiFePO4 battery, it will outlast my use. So in my case I don't sweat charging at -10C.
Now if this was an EV where the goal was to have a 200,000 mile lifetime, then the calculus would be different.
I think the most important thing to realize is that there are no black and white rules or limits. You can charge below freezing, you can run down to 0% SOC, you can cycle at high temperatures, it is all a trade off between usability and lifetime.
I only had a cursory understanding of the ins and outs of LifePo4 just a month ago. Been processing a lot of info in the week or so since I built this LifePo4 battery pack. Still trying to put all these baselines and various risk factors into perspective. Thanks for all your help!jaycocreek wrote:
Nice spec sheet but I don't see anything on internal cell type and how there configured..Battleborn makes a deal about there cylindrical cells and discharging to 0% and stated some other types cannot do that..Just another interesting point other companies don't discuss...
This is not really important to the end user - just that the battery meets its specifications.
