Lithium LifePo4 12v Batteries - Time For An Upgrade?
- Thread starter Dellmassive
- Start date
@Dellmassive , so is there a DC/DC charger available that will charge at the 14.6v that battery would prefer? And a solar charger, would my Victron 100/20 be good enough (I realise the current would depend on the sun)? I'm at the point where I would change to lithium when needed, but it seems a bit daft doing it now when my current setup is still covering my needs. The ability to draw big currents is what's pulling me in.
Charging a LifePo4 Battery:
Most chargers now days have a lithium charge profile.
Which seems to be CC/CV and two stages Absorption and float. And a voltage of around 14.2-14.6v absorption and 13.8v float. (check you battery spec sheet)
My battery spec was to charge at 14.6v .... but my chargers are at 14.2v.... this hasn't been an issue and the battery charged fine.
So any dc-dc or charger with a lithium profile will work..... technically any charger will work provided its CC/CV and at the correct voltage 14.2v -14.6v ish (check you battery spec sheet),(but it might not fully charge it properly if not set to a lithium charge profile) but Im just a bit happier knowing I had the charger set to a lithium profile. So it doesn't seem critical about the voltage, as long as it's over 14.0v... (infact when charging I never saw more than 14.0 across the battery terminals, because as the voltage in the battery rises to near the supply voltage the current drops off.) ( the charger was putting out 14.2 and the battery was sitting at 14.1v 100% charged)
Also without a DC-DC a large lithium flat battery will cause a massive load on any alternator or SCR as shown on the victron testing video below, so be warned ! without a DC-DC you could damage your alternator/SCR setup . . . Also the lithium's sit at a higher charged rest voltage, mines at 13.8v so you defiantly dont want to add it to a system with a SCR and a AGM starter battery at 12.4V - the lithium will try and discharge into the AGM starter . . . . . so id say a DC-DC is a must for Lifepo4. . . . . some manufacturers say you dont need a special charger and they will charge off the alternator, which is true to a degree, but as you see below victron vid there is a very good chance you will fry your alternator and SCR. The other thing is most Lithiums state the max charge voltage is 14.6v (going above this will damage the battery) . . . . with our smart alternators we see 15.0v during regeng braking (most internal BMS will disconnect the battery at high voltage, but thats a safety thing and not for every day use.) . . . . . So can we use a Lifepo4 battery on a T6 EU6 without a DC-DC charger? - - - - simple answer is no.
My battery started at 12.8v ...
Which was basically about 10% charged.... then showed a gradual rise as it was charging... and ended up at 14.0v..... then dropped to 13.8v after resting a while.
I also tried it on the victron mppt 100/20 solar on the shed.... that worked fine too...... I just changed the battery type in the victron mppt 100/20 menu to lithium....it started charging up go the max current it could....which yesterday was about 8-12amps.
FWIW I'll be upgrading my redarc bcdc1240 DC-DC charger for the bcdc1250d because the new one has a lithium charge profile and built in MPPT, but ill still be using a 3rd party Victron MPPT.
Most chargers now days have a lithium charge profile.
Which seems to be CC/CV and two stages Absorption and float. And a voltage of around 14.2-14.6v absorption and 13.8v float. (check you battery spec sheet)
My battery spec was to charge at 14.6v .... but my chargers are at 14.2v.... this hasn't been an issue and the battery charged fine.
So any dc-dc or charger with a lithium profile will work..... technically any charger will work provided its CC/CV and at the correct voltage 14.2v -14.6v ish (check you battery spec sheet),(but it might not fully charge it properly if not set to a lithium charge profile) but Im just a bit happier knowing I had the charger set to a lithium profile. So it doesn't seem critical about the voltage, as long as it's over 14.0v... (infact when charging I never saw more than 14.0 across the battery terminals, because as the voltage in the battery rises to near the supply voltage the current drops off.) ( the charger was putting out 14.2 and the battery was sitting at 14.1v 100% charged)
Also without a DC-DC a large lithium flat battery will cause a massive load on any alternator or SCR as shown on the victron testing video below, so be warned ! without a DC-DC you could damage your alternator/SCR setup . . . Also the lithium's sit at a higher charged rest voltage, mines at 13.8v so you defiantly dont want to add it to a system with a SCR and a AGM starter battery at 12.4V - the lithium will try and discharge into the AGM starter . . . . . so id say a DC-DC is a must for Lifepo4. . . . . some manufacturers say you dont need a special charger and they will charge off the alternator, which is true to a degree, but as you see below victron vid there is a very good chance you will fry your alternator and SCR. The other thing is most Lithiums state the max charge voltage is 14.6v (going above this will damage the battery) . . . . with our smart alternators we see 15.0v during regeng braking (most internal BMS will disconnect the battery at high voltage, but thats a safety thing and not for every day use.) . . . . . So can we use a Lifepo4 battery on a T6 EU6 without a DC-DC charger? - - - - simple answer is no.
My battery started at 12.8v ...
Which was basically about 10% charged.... then showed a gradual rise as it was charging... and ended up at 14.0v..... then dropped to 13.8v after resting a while.
I also tried it on the victron mppt 100/20 solar on the shed.... that worked fine too...... I just changed the battery type in the victron mppt 100/20 menu to lithium....it started charging up go the max current it could....which yesterday was about 8-12amps.
FWIW I'll be upgrading my redarc bcdc1240 DC-DC charger for the bcdc1250d because the new one has a lithium charge profile and built in MPPT, but ill still be using a 3rd party Victron MPPT.
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Just been watching about LiFeYPo4 batteries (the Y is for Ytrium), apparently they don't suffer from the low temperature problem and can be charged well below zero. Nominal voltage 3.2v so a 4S pack would be fine for a 12v application. The only issue I can see is that on first calculation they seem to be slightly bulkier. Here's an example 100ah Lifeypo4 Thundersky Winston Battery - Buy 100ah Lifeypo4 Battery,Thundersky Winston Battery,Lithium Battery Product on Alibaba.com
Edit: Actually on using proper maths without fingers, the size is fine.
Any drawbacks?
Edit: Actually on using proper maths without fingers, the size is fine.
Any drawbacks?
Yes. Minimum order is 50 units. That's a drawback. An expensive one at that.
That was just an example for spec sheets, Alibaba is bulk buying but they are available in single units on other sitesYes. Minimum order is 50 units. That's a drawback. An expensive one at that.
I've bought a fair bit through Aliexpress (Alibaba). All low value, non safety critical stuff. Highest value item was 60 quid. However, I've not crossed the bridge to buy anything safety critical that I cant properly examine. Knowing what lithium is capable of, when it goes wrong and the fact that my testicles will be 4 to 6 inches from the positive/negative terminals, what should we be looking for in terms of safety standards and compliance, when deciding on what lithium battery to purchase.
Agreed, but that brand is apparently well known and highly regarded. I've bought work related equipment into the hundreds from Aliexpress without issues, though bare in mind that they're just an intermediary like Ebay and your experience will depend on the individual merchant. Much of the stuff I've bought is made in China anyway (optical equipment) but bought from a UK agent, there is often a 4 to 5 x markup. In one case 7 x !!
Maybe a market for testicle earthing straps?
How mad.
Just watch this today.... using those cells!!!
.
Think ill see what the big boys do regarding a large 100ah pack with built in bms etc.... atm I'll stick with the lifepo4... but will keep a close eye on that battery tech.
WB-LYP100AHA LiFeYPO4 (3.2V/100Ah TALL)
EV-Power | WB-LYP100AHA LiFeYPO4 (3.2V/100Ah TALL)
High power lithium cell, original Winston Battery product with LiFePO4 (LiFeYPO4) technology. Capacity: 100Ah, size: 218x143x67 mm, weight: 3.3 kg. Model: WB-LYP100AHA(A)
Technical information
Complete datasheet
Original ThunderSky Winston part number: WB-LYP100AHA(B)
Recommended initial and subsequent charging is to 3.65 V.
The minimum voltage is 2.5 V.
Maximum discharge current is 3C continously.
Operating temperature -45°C up to 85°C (discharging)
Energy density is 90.9 Wh/kg
These battery cells are suitable for all traction applications including electric vehicles. Fully complies also for stationary applications - such as energy storage.
There is no Selfdischarging effect.
Can be recharged at any state of discharge - no memory effect
LiFePO4 is a very safe technology, not spontaneous combustion, does not react with moisture or with oxygen.
All cells are supplied new directly from the manufacturer.
Original Woodenbox contains 20 cells is 647*458*360mm large and weights 74kg.
Connecting the cells
Winston produce cells with easy to assemble square shape, terminals are made for screws allowing simple installation with spanner.Interconnection between cells is important part of any battery pack. Original copper connectors are made of several thin layers for ideal flexibility and conductivity.
Make sure to clean oxidation from both, terminals and connectors (with Sandpaper or similar) before assembly. Oxided contacts may have very high resistance and cause unbalancing of the battery.
Plastic caps are cheap solution to prevent unwanted shortcuts and for easy plus and minus marking (red and black colors are available).
Demonstration video of cell assembly
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Working my way through the above videos this eve. Very interesting.
Two things.
400 mile's from home just now so mains hook up isn't practicle. Groceries, milk, Lurpark, Guiness and some unpronounceable wine the wife drinks, in the van fridge. While out walking round Thorpness, the interior of the van, while parked up, hit 32C. Granted windows were closed. But running the fridge was essential. Spent much of today with the clamp meter and BM2 app, monitoring solar input and current draw on the battery willing it back up to full charge and wishing the clouds would bugger off. Running the engine at tick over to charge the leisure battery, isn't good for the DPF. Driving about adds miles on the van and hastens the next service. But knowing how AGM degrades with misuse, it's becoming an obsession to get electrons back into the battery. Seems like lithium however, is a fit and forget solution. Expensive, but peace of mind is perhaps priceless.
Secondly, @Bryn23 has hit on something. I spent over a grand on a Webasto diesel hob (didn't want gas). But for about same money, you could buy an induction hob and lithium battery and get them the full 100Ah of benefit. You still need an inverter but that cost is irrelevant, as its fitted regardless of what type of battery I have. But offset the cost of an AGM and it properly starts to make financial sense.
FOR SALE- Webasto X100 diesel hob. Light use. Open to offers.
Two things.
400 mile's from home just now so mains hook up isn't practicle. Groceries, milk, Lurpark, Guiness and some unpronounceable wine the wife drinks, in the van fridge. While out walking round Thorpness, the interior of the van, while parked up, hit 32C. Granted windows were closed. But running the fridge was essential. Spent much of today with the clamp meter and BM2 app, monitoring solar input and current draw on the battery willing it back up to full charge and wishing the clouds would bugger off. Running the engine at tick over to charge the leisure battery, isn't good for the DPF. Driving about adds miles on the van and hastens the next service. But knowing how AGM degrades with misuse, it's becoming an obsession to get electrons back into the battery. Seems like lithium however, is a fit and forget solution. Expensive, but peace of mind is perhaps priceless.
Secondly, @Bryn23 has hit on something. I spent over a grand on a Webasto diesel hob (didn't want gas). But for about same money, you could buy an induction hob and lithium battery and get them the full 100Ah of benefit. You still need an inverter but that cost is irrelevant, as its fitted regardless of what type of battery I have. But offset the cost of an AGM and it properly starts to make financial sense.
FOR SALE- Webasto X100 diesel hob. Light use. Open to offers.
One thing I wish I had done is gotten the larger dc-dc charger, maybe the 45 or 60ah version over the 30ah version I have.
Having said that, we left in early July and we haven’t needed to plug into mains power to charge the batteries and I haven been under 50% SOC yet.
But we do quite bit of exploring, hence I’d want a faster charger for smaller trips.
Donkey, I’d keep the diesel heater if it’s already fitted, although I’d expect to see quite a few new low power RV dual induction cookers in the next 18 months.
Having said that, we left in early July and we haven’t needed to plug into mains power to charge the batteries and I haven been under 50% SOC yet.
But we do quite bit of exploring, hence I’d want a faster charger for smaller trips.
Donkey, I’d keep the diesel heater if it’s already fitted, although I’d expect to see quite a few new low power RV dual induction cookers in the next 18 months.
I doubt it. The leisure market is too small compared to the industrial applications which at the moment is the main consumer. This is why there are very few of them with LTD, the batteries tend to mostly live in a temperature controlled environment.
Just a couple of cautions. If you are going to fashion some kind of LTD (Edit-LTD) (typo-LBD) and use a DC-DC charger I suggest that you fit the disconnect on the input side to the charger. Most DC-DC chargers like to have the leisure battery connected before the vehicle battery so having a disconnect on the output side could cause an issue.
The other thing is, this thread is mostly of interest to "extreme users" and does not mean that you should go down this route if you have a camper conversion that get used mostly on camp sites with mains hook up or if you only run a few LED lights and USB chargers.
If you wanted a vehicle to run around locally and do a bit of shopping then a Fiesta or similar would do the job. However, if you drive down to the south of France every weekend then a nice Bentley would improve your life no end!
Horses for courses, just saying.
The other thing is, this thread is mostly of interest to "extreme users" and does not mean that you should go down this route if you have a camper conversion that get used mostly on camp sites with mains hook up or if you only run a few LED lights and USB chargers.
If you wanted a vehicle to run around locally and do a bit of shopping then a Fiesta or similar would do the job. However, if you drive down to the south of France every weekend then a nice Bentley would improve your life no end!
Horses for courses, just saying.
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I was thinking with the Ablemail @travelvolts , that intercepting the sense wire permanently attached to the positive battery terminal and fitting the relay from the temp sensor there would be a solution. However, that wouldn't isolate the supply from the solar panel. Albeit, in winter when the temp is low, the light level will be lower. Usually.
Is that a typo @travelvolts ?
did you mean LTD (low temp disconnect?) (to prevent charging at low temps) - good shout on fitting on the DC-DC "starter" side. (what would you suggest about the 3rd party solar charging side too? ( if your solar charger didn't have built in low temp disconnect) a second disconnect? (the victron can have a battery temp sensor fitted so not an issue in my case, but what about people who have other solar charger without temp . . . that may also need a LTD on the solar side)
the LBD (low battery) would be on the battery output between the loads positive terminal to disconnect at about 11.5v in case the battery was run to low. (but the charge side, say DC-DC would still be connected so that DC-DC was happy and could still charge providing it wasnt to cold)
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