Lithium Phosphate batteries

Gents

Gents

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Hi Funsters, I’m thinking of going mad & putting a whole new set up in my PVC.
I know it’s not going to be cheap but I like the idea of not being tied to hook up pitches.
Looking at Solar panels, inverter, B2B charger & 2 x 145W Lithium phosphate batteries. “Ouch, I hear you cry”. Me too,
would just like any feedback on what I am suggesting. I am looking for the extra easy life, the big 70 in Feb.
 
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For what it's worth ---- I have lost count of how many LiPo's I've had to replace. Not in my moho, thank goodness, but in model planes and model boats, we use them a lot. Smallef of course, but same chemistry ? ?
We probably use them more to their extremities than a moho would, so I do hope they will last much longer. ?
Remembering that laptop batteries etc, are reliable, but do not use lipos, I have to wonder if lipos are just stealing their reputation ?
I recently bought two new LiPo's, one excellent, the other useless !
Fantastic weight savings, excellent long term charge retention, but I still have great reservations on lifespan compared to lead acid.
Just my experiences. I'm not claiming to be an expert ! 😀 but I know I will certainly stay with lead acid for some years yet for my own moho !
 
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Hi I have read many threads on the subject of batteries, and we all have had bad and good results from the same types, ! The guy above has done the same and posted calculated results, (with the emotions taken out)
He has many post I,m sure you will find one that suits your requirements. including Lithium /solar RV set ups
 
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Golden Graham ! said:
For what it's worth ---- I have lost count of how many LiPo's I've had to replace. Not in my moho, thank goodness, but in model planes and model boats, we use them a lot. Smallef of course, but same chemistry ? ?
We probably use them more to their extremities than a moho would, so I do hope they will last much longer. ?
Remembering that laptop batteries etc, are reliable, but do not use lipos, I have to wonder if lipos are just stealing their reputation ?
I recently bought two new LiPo's, one excellent, the other useless !
Fantastic weight savings, excellent long term charge retention, but I still have great reservations on lifespan compared to lead acid.
Just my experiences. I'm not claiming to be an expert ! 😀 but I know I will certainly stay with lead acid for some years yet for my own moho !
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No the chemistries are very different and they are designed for very different purposes. There are at least 4 types that I know of. The LiFePO4 type is used for leisure batteries.
(Sorry about the big shouty print I did a cut and paste)
Lithium Cobalt Oxide(LiCoO2) — LCO
Lithium Manganese Oxide (LiMn2O4) — LMO
Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO2) — NMC
Lithium Iron Phosphate(LiFePO4) — LFP
 
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There is another one Li4Ti5O12 Lithium Titanate LTO,
Li po’s are not a battery chemistry type it’s just Li polymer gel added to LCO’s cathode. Some ppl think the lipo is different but it isn’t, its the gel in the LCO
 
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Wow, I think I have a bit of research to do now, I like the sound of these replies.
Again, I say thanks a bunch for your interest.
FUNSTERS RULE I WOULD SAY !!!!
Because of approaching the big 70 ( whilst still thinking like a 20 year old) I just want to cut out all the time wasted not having Fun. What is it they say, Growing Old is inevitable, Growing up is Optional.
That’s me.

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Useful if you have something that needs 240 volts. I bought a cigarette charger for my MacBook Air, but after a while it died, so I used the inverter instead. I also bought a 240 volt tv (28” A++ one). It’s not like the inverter is on all the time, though even if they need to be, you can minimise the effect of that.
 
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Hi Guys
I think if weight and space was not an issue then I would of thought most of us would go for the lead acid or gel type; just for cost and cheaper replacement; but having to go down to a 3500kg MH and a small payload which most of 3500kg MHs seem to have then it would be beneficial to not eat into the small payload by using heavy batteries.

I have at the moment on my Autotrail Tag axle 5000kg MH 4 x 100AH batteries with a battery to battery charging system and 300watts of solar panels with a Victron controller; which has served me well.

Having to move down to a 3500kg MH in about a year and a half; fitting two 100 Lipo batteries and the systems to service them would give me just as much usable power as the 4 batteries at a great weight saving; which to me is a great way if not an expensive way of not eating into the small payload of the 3500kg MH.
Best Wishes Tony

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For me it is about weight & peace of mind. If I was 50 years younger it probably be about cost, but at this point, I like the fact that if your battery is 100 amp hr, that is what you get, and usable till dead, apparantly no drop off in power, then, bingo, charge back up in next to no time. So having worked out my power needs, and looked at all the for’s and against’s, I think I will fit one 145 amp/hr + as much solar as will fit on the roof, with a monitor and add if necessary.
Thanks Guys, for your very valued input, what a wealth of knowledge 👏👏👏👏.
 
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Gents said:
For me it is about weight & peace of mind. If I was 50 years younger it probably be about cost, but at this point, I like the fact that if your battery is 100 amp hr, that is what you get, and usable till dead, apparantly no drop off in power, then, bingo, charge back up in next to no time. So having worked out my power needs, and looked at all the for’s and against’s, I think I will fit one 145 amp/hr + as much solar as will fit on the roof, with a monitor and add if necessary.
Thanks Guys, for your very valued input, what a wealth of knowledge 👏👏👏👏.
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Well that's not quite true....if you regularly run a Lithium below 20% you will seriously shorten its lifespan..
 
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Garry Walden said:
Well that's not quite true....if you regularly run a Lithium below 20% you will seriously shorten its lifespan..
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Heavy use reduces the capacity and life span of all types of battery. The number of cycles the manufacturers give is the number of cycles before it reaches 50% capacity. In other words your 100Ah battery slowly loses capacity from day 1, so when you are half way through the life of your 100Ah battery it has become a 75Ah battery. This is why the cycle life is so important, it is not just how often it officially needs replacing but at what point it no longer has enough capacity left to not let you down. The picture below is the graph for my Relion RB100 LiFePO4.

Even with an Li battery I try to limit the depth of discharge (DOD) to 40% so that it stays close to 100Ah longer.
 

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funflair said:
Likewise they don't like sitting at 100% so looking after your lithiums is whole new discussion ;)
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That 100% storage advice is for long term storage of over 3 months and does not apply to normal use. This is the off season storage advice given by Relion.
“Simply charge your battery to 14.4 volts, disconnect the battery from your charger, and your equipment, then store in temperatures anywhere between 23°F to 95°F (-5°C to 35°C). For storage longer than 3 months, the recommended temperature range is 32°F to 77°F (0°C to 25°C), then it’s safe to store at a 50% state of charge. Unlike lead-acid batteries, a partial state of charge does not harm lithium batteries.”

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Pausim said:
That 100% storage advice is for long term storage of over 3 months and does not apply to normal use. This is the off season storage advice given by Relion.
“Simply charge your battery to 14.4 volts, disconnect the battery from your charger, and your equipment, then store in temperatures anywhere between 23°F to 95°F (-5°C to 35°C). For storage longer than 3 months, the recommended temperature range is 32°F to 77°F (0°C to 25°C), then it’s safe to store at a 50% state of charge. Unlike lead-acid batteries, a partial state of charge does not harm lithium batteries.”
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So 3 months over winter outside your house on hook up wouldn't be good for them?

And somebody else says,

Storing Lithium-Ion Batteries

The very low self-discharge rate makes it easy to store LFP batteries, even for longer periods. It is no problem to put a lithium-ion battery away for a year, just make sure there is some charge in it before placing it in storage. Something between 50% – 60% is ideal, that will give the battery a very long time before self-discharge brings the Voltage close to the danger point.
Storing batteries below freezing is fine, even at very low temperatures such as -40 Centigrade (that is the same in Fahrenheit), or even less! The electrolyte in LiFePO4 cells does not contain any water, so even when it freezes (which happens around -40 Centigrade, depending on the particular formulation) it does not expand, and does not damage the cells. Just let the battery warm up a bit before you start discharging it again, which is OK at -20 Centigrade and above. You will see an apparent loss of capacity when discharging at below-freezing temperatures that reverses when the battery gets above freezing, and there is a slightly accelerated effect on aging. Storing them at low temperatures is certainly much better than storage at high temperatures: Calendar aging slows down dramatically at low temperatures. Try to avoid storing them at 45 Centigrade and above, and try to avoid storing them completely full if possible (or nearly empty).
If you need to store batteries for longer periods, be sure to simply disconnect all wires from them. That way there can not be any stray loads that slowly discharge the batteries.
 
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Pausim said:
Heavy use reduces the capacity and life span of all types of battery. The number of cycles the manufacturers give is the number of cycles before it reaches 50% capacity. In other words your 100Ah battery slowly loses capacity from day 1, so when you are half way through the life of your 100Ah battery it has become a 75Ah battery. This is why the cycle life is so important, it is not just how often it officially needs replacing but at what point it no longer has enough capacity left to not let you down. The picture below is the graph for my Relion RB100 LiFePO4.

Even with an Li battery I try to limit the depth of discharge (DOD) to 40% so that it stays close to 100Ah longer.
Click to expand...
Now I was under the impression that the Lithium was made to run its full depth, rather than short bursts. However if I install plenty of Solar, won’t that automatically top up, I know that the amount of sun will determine the capacity. Also I downsized to a PVC because more often than not, I would run the engine to go out and about each day, & like being able to get in small places,so again they would be topped up. I also use the van constantly as a day van throughout the year.
 
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Gents said:
Now I was under the impression that the Lithium was made to run its full depth, rather than short bursts. However if I install plenty of Solar, won’t that automatically top up, I know that the amount of sun will determine the capacity. Also I downsized to a PVC because more often than not, I would run the engine to go out and about each day, & like being able to get in small places,so again they would be topped up. I also use the van constantly as a day van throughout the year.
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It will run to its full depth and still last a lot longer than a lead acid one but it will last even longer the fewer times this happens. Solar should keep it topped up so that this doesn’t happen very often.
 
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funflair said:
So 3 months over winter outside your house on hook up wouldn't be good for them?
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I don’t think it will do any serious harm in 3 months, the battery charger will drop back from 14.4V to about 13.6V. However it would only be a matter of removing the negative battery connection if it worried you.
 
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Gents said:
Now I was under the impression that the Lithium was made to run its full depth, rather than short bursts.
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Better to install a slightly bigger battery, and cycle between 10% and 90% - or better, 20% to 80% - and they will last for probably longer than the engine. Keep away from extremes. And with lithium there's no big reason to quickly recharge to 100% like you have to do with lead-acids.

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Garry Walden said:
Well that's not quite true....if you regularly run a Lithium below 20% you will seriously shorten its lifespan..
Click to expand...
I understand that all batteries reduce with use, & age, I didn’t mean 100% till dead, I didn’t explain myself very well, sorry, what I meant was with lead etc batteries they quote let’s say 100 A/hr but what you actually get, is, say 60, and on top of that the actual out put drops off rapid so say using a Microwave , You can get it working at correct power when battery is charged, but in no time at all the output reduces significantly so as not able to power microwave, where as Lithium gives full power output till drained, that is what I meant.
 
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Pausim said:
Heavy use reduces the capacity and life span of all types of battery. The number of cycles the manufacturers give is the number of cycles before it reaches 50% capacity. In other words your 100Ah battery slowly loses capacity from day 1, so when you are half way through the life of your 100Ah battery it has become a 75Ah battery. This is why the cycle life is so important, it is not just how often it officially needs replacing but at what point it no longer has enough capacity left to not let you down. The picture below is the graph for my Relion RB100 LiFePO4.

Even with an Li battery I try to limit the depth of discharge (DOD) to 40% so that it stays close to 100Ah longer.
Click to expand...
Looking at that graph if you were to discharge 100% every single day if would take 6000 cycles or over 16 years for the capacity to drop to 50%.
So for use in a Motorhome you could be pretty brutal with them and they would still outlast the van.
Most of us with a decent solar bank are very unlikely to ever do a 100% discharge.
In my 14 years of Motorhoming with Gel batteries I think I have only done a full discharge once (first van before I fitted solar) and only once or twice gone below 40% and I rarely use EHU over 90% of our camping is off grid.
 
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I have a 100ah TN Lifepro battery for sale with a sterling power 30A b2b charger as well, if you interested bought for my Swift but was to big to fit under the drivers seat so had to get a smaller one, if you interested let me know its sat hear doing nothing so going cheap ????
 
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The other thing to consider Pausim in that graph is a 0,5C rate. That’s pretty stiff for continuous discharge even for LFP. You can go as high as 1C some even 3C but not for long. Winston are capable of 3C without breaking a sweat, low grade Chinese like gtk above 0,5C are struggling. Most are 0,2-0,3C continue discharge for good life. There are studies that elevated voltage does degrade a lot more compared to taking a cell bellow 3v. Keeping a battery on float at 13,6v for three months, it will definitely do some damage, but dipping bellow 10% is not as bad. The only danger is unbalanced cells, but for that is the bms to protect the pack for low voltage. I charge in summer to 13,6v with 15mins absorb time, and 13,7v in winter, but I will not hesitate to take it below 10%. I have enough capacity not to bother for the extremities. Once the pack has been at least once at 14,4v and it forms the sei layer, you got no reason to go that high again, except for periodic triger of cell balance. This is achieved at just over 3,4vpc or 13,6v. From this voltage to 3,6v there is very little energy and it’s not worth the stress of the cell to hunt a 100% charge. When you buy cells or batteries, they come from 40 to 60 % charged. Majority I bought was at 40, for shelf life.
 
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autorouter said:
As Lenny HB says, you need to clarify this. Battery capacity is not measured in watts, but in watt-hours (Wh). Alternatively it can be measured in amp-hours (Ah). If you know the battery voltage you can convert between them easily:
Watt-hours = amp-hours x voltage.
So for example for a 12 volt battery 100Ah = 1200Wh
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Raul said:
I think he made a typo and should read 2x145ah, but as you guys pointed, he should confirm.
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I really don't think there was any need for clarification....ir was obviously a mistake on the OPs part.
2 x 12.5ah batteries is unfeasible on a motorhome. .... Even my lawnmower battery is 30ah.

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pappajohn said:
I really don't think there was any need for clarification....ir was obviously a mistake on the OPs part.
2 x 12.5ah batteries is unfeasible on a motorhome. .... Even my lawnmower battery is 30ah.
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2x145Ah is not a common size. The '2x145W' could just as easily have been a typo for 2x1450Wh, which is 2x120Ah, a common size. Batteries are often specced in Wh on sites aimed at the home/offgrid market.
 
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