Lithium battery suppliers

nabsim

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i am poor on knowledge it’s all electrickery to me but as i understand it the lithium charges fast and is used in the first instance but also constantly trickle charges the lead element , i’m not a big power user very rarely turn on tv but run my fridge freezer for several hours a day off inverter, lpg wise i probably use less than a ltr a day in the summer and double that in the winter
I thought the idea was the charger goes onto the lead acid technology so you didn’t need a Lifepo4 profile Ken? Saying that in a lot of cases a gel profile is close enough. If charger goes to Lifepo4 using a Lifepo4 profile it makes more sense to me but I still don’t get how it can fully charge either agm or gel lead carbon faster. Will have to wait and see if David can get it through my head :)
 

SquirrellCook

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It was the long absorption time that annoyed me with Lead Acid. I looked at lead carbon, but after the hassle of trying to buy some T105 6 volt ones I decided it would be cheaper to go Lithium. Ok I took the Chinese long weight route. I've made up two 12 volt 202ah each with it's own BMS that take up the same space as the T105's. I don't think I would have done it paying retail prices. Lets see what happens.
 

nabsim

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It was the long absorption time that annoyed me with Lead Acid. I looked at lead carbon, but after the hassle of trying to buy some T105 6 volt ones I decided it would be cheaper to go Lithium. Ok I took the Chinese long weight route. I've made up two 12 volt 202ah each with it's own BMS that take up the same space as the T105's. I don't think I would have done it paying retail prices. Lets see what happens.
I totally forgot about self build Lifepo4, that would probably negate a lot of the cost difference
 

wildebus

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Must admit I get a bit confused with Hybrid battery banks. I can’t see how you can fast charge them without damage. The original problem with agm battery’s was chargers putting too much charge too quickly wasnt it? Gels although more tolerant need long time to top up. Neither gel or agm will reach 100% SoC without a long charge will they?
..... Questions posed as I can’t get my head round the fast charge bit on hybrid
The Fast Charging happens with the Lithiums.
What happens is the general load is satisfied by the Lithiums, with the Lead coming in to assist when there are heavier loads (that includes spikes from something like a Compressor Fridge kicking on).
And then when Charging occurs, the same in reverse - the charging current goes into the Lithiums
This can be seen in my van in the graph below showing both discharge and recharge over a couple of weeks
The wavy Green line is the Lithium SOC, providing the day to day power;
The Orange flat line is the Lead SOC, gradually going down due to the fridge compressor spiking.
The Black line is the overall SOC of the Hybrid bank.
Screenshot 2022-07-27 at 14-17-06 Monty - VRM Portal.png
And it is only when the Lithium goes down to around 10% SOC that the Leads actually come into regular use.
The Lead in a Hybrid setup provides a number of features - a bit of a reserve tank if your had a period of usage more than usual or if the charging is less than usual (may a few days of rain or cloud?); Or if you have an occasional heavy load which is beyond the ability of the Lithiums BMS current rating (that is often a limiting factor).
And as Ken has mentioned, because the Lead is generally little used as a matter of course, it is sitting there at a high State of Charge and so the Service Life is greatly extended compared to a Lead Battery Bank in standard use. In the graph below, the overall SOC dropped to 50% at the lowesr, but the Lead part never dropped below 75%.
 

nabsim

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Okay, think I nearly have it now, you have probably explained it before and I have forgotten. I can see from the graph that when your lead Carbon bank drops it can take days to get back to full, which is what I would have expected.

Physical connections for hybrid, would you parallel the lead side then piggy back the lithium or do you treat it totally as one big bank. E.g. charge source positive one end of lead bank and negative on the other and the opposite with positive then just connect the lithium in separately? Not sure if I have explained what I mean or not lol

Charge sources flowing through lead carbon bank then piggy back lithium in and all discharge taken from lithium?

Stopping at that before I confuse myself. Will try another explanation if this is incomprehensible lol
 

wildebus

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Okay, think I nearly have it now, you have probably explained it before and I have forgotten. I can see from the graph that when your lead Carbon bank drops it can take days to get back to full, which is what I would have expected.
The only reason the Lead Carbon is not recharging is that all the recharge current is going into the Lithium and during this period shown I am not really getting enough to recharge the Lithium fully anyway.
Maybe I will plug the van into EHU and you will see how the charging works when both battery banks are in need of charge (as of right now, Lithium is at 47%, so needs around 110Ah into it; and Lead is at a reported 85%, so needs around 45Ah into those batteries.)

Physical connections for hybrid, would you parallel the lead side then piggy back the lithium or do you treat it totally as one big bank. E.g. charge source positive one end of lead bank and negative on the other and the opposite with positive then just connect the lithium in separately? Not sure if I have explained what I mean or not lol

Charge sources flowing through lead carbon bank then piggy back lithium in and all discharge taken from lithium?

Stopping at that before I confuse myself. Will try another explanation if this is incomprehensible lol
The way I have it setup is cable up the 3 Lead Carbons in Parallel in the usual way (i.e. Balanced connections for that bank); and 2 Lithiums in Parallel in the usual way. So Lead Bank and Lithium Bank. And think of each as a single battery so you end up logically with two "batteries" - one Lead and one Lithium
You then Parallel the Lead and the Lithium - -ve to -ve, and +ve to +ve. And those common -ve and +ve connections are the Tap Off points for the "Hybrid Battery" as presented to the Camper/Motorhome. In my own case, I have Lead -ve and the Lithium -ve going to a common point, that being a BMV Shunt; and I have the Lead +ve and the Lithium +ve going to a common point, that being an Isolation Switch
So both Banks are connected to the Habitation system equally and nothing goes through one technology in order to get to the other technology - it is using the BMV Shunt and the Isolation Switch effectively as Busbars with 3 connections on each - MH Loads/Charges; Lead Battery; and Lithium Battery.

However, and this is quite an important thing, you connect a control relay, such as my VSDR Lithium Controller, between the +ve of the Lithium Bank and +ve of the Tapoff point (in my case the Isolation Switch), which allows you to (automatically) disconnect the Lithium when charged and have the charging system continue to charge the Lead.
I would also fit a suitable fuse as well on that line as all power lines should be protected. This would be the case if it were 100% Lead or 100% Lithium as well.
 

Trotter

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The way I have it setup is cable up the 3 Lead Carbons in Parallel in the usual way (i.e. Balanced connections for that bank); and 2 Lithiums in Parallel in the usual way. So Lead Bank and Lithium Bank. And think of each as a single battery so you end up logically with two "batteries" - one Lead and one Lithium
You then Parallel the Lead and the Lithium - -ve to -ve, and +ve to +ve. And those common -ve and +ve connections are the Tap Off points for the "Hybrid Battery" as presented to the Camper/Motorhome. In my own case, I have Lead -ve and the Lithium -ve going to a common point, that being a BMV Shunt; and I have the Lead +ve and the Lithium +ve going to a common point, that being an Isolation Switch
So both Banks are connected to the Habitation system equally and nothing goes through one technology in order to get to the other technology - it is using the BMV Shunt and the Isolation Switch effectively as Busbars with 3 connections on each - MH Loads/Charges; Lead Battery; and Lithium Battery.

However, and this is quite an important thing, you connect a control relay, such as my VSDR Lithium Controller, between the +ve of the Lithium Bank and +ve of the Tapoff point (in my case the Isolation Switch), which allows you to (automatically) disconnect the Lithium when charged and have the charging system continue to charge the Lead.
I would also fit a suitable fuse as well on that line as all power lines should be protected. This would be the case if it were 100% Lead or 100% Lithium as well.
Please read my PM
 

nabsim

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2,870
…….

However, and this is quite an important thing, you connect a control relay, such as my VSDR Lithium Controller, between the +ve of the Lithium Bank and +ve of the Tapoff point (in my case the Isolation Switch), which allows you to (automatically) disconnect the Lithium when charged and have the charging system continue to charge the Lead.
I would also fit a suitable fuse as well on that line as all power lines should be protected. This would be the case if it were 100% Lead or 100% Lithium as well.
Just been looking at this again David and the last paragraph I quote above jumped out. Do you have to do this in all cases or is it particular to instances like yours. If I just joined one lead acid and one Lifepo4 battery together would the lithium need to disconnect when 100%?
 

wildebus

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Just been looking at this again David and the last paragraph I quote above jumped out. Do you have to do this in all cases or is it particular to instances like yours. If I just joined one lead acid and one Lifepo4 battery together would the lithium need to disconnect when 100%?
Do you HAVE to do it? The answer is no, and for many months after my initial Hybrid installation I didn't have a disconnect method between the two typres of battery. However, what you then need to do is setup the chargers with Lithium profiles, which means the typical Lead battery does not get a full charge - and for a Lead Battery, that results in a permanent reduction in capacity on the Lead.
Lead Carbons are less affected as they usually are happy with a lower charge voltage and also can stay at a PSOC (Partial State of Charge) for longer without affected the battery. So what you can do in that setup is occasionally disconnect the Lithium manually (take the fuse out, say, or remove the connection) and do a full Lead recharge at the Lead charge voltage.
My setup with the type of batteries I have it is actually a little less important to have the relay but personally, I have always preferred the automatic "fit and forget" approach so the automated connect/disconnect relay process works best.
 

nabsim

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Was asking before telling Charlie to add one of his Lifepo4 battery’s to the small lead acid battery on his new van. If it’s more complicated than connecting the battery I don’t think he will want to do it. He could pull the lead acid and just run the one or both the Lifepo4 though, was just thinking hybrid may have been an easier option ,for him
 

wildebus

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Was asking before telling Charlie to add one of his Lifepo4 battery’s to the small lead acid battery on his new van. If it’s more complicated than connecting the battery I don’t think he will want to do it. He could pull the lead acid and just run the one or both the Lifepo4 though, was just thinking hybrid may have been an easier option ,for him
it is an interesting way to add lithium without changing your chargers :)
 

SquirrellCook

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I just didn't have the room to do a hybrid system in Murky, so now it's 100% Lithium (home assemble) 404Ah. It ran the fridge last night with no problems. Setting up the charge voltage and BMS settings have been fussier than with lead. If all is well in a couple of weeks I'll have a couple of 6 volt trojan T105's looking for a new home.
 

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