NX Pajero Twin Lithium Batterys under bonnet

[Bru9]

[QUOTE=Maccaman194;633197iThe internal BMS in the batteries disconnects the 13.7V float when the batteries are charged fully anyway. I see that on the bluetooth app. Batteries go to "Standby" status; no amps in.[/QUOTE]

How can the BMS disconnect the 13.7V float with only two exposed terminals? Without killing loads or disconnecting from the alternator which is a no-go. Most bms are just a switch that sits inline between the neg leg and are purley a catastrophic fail safe. when the bluetooth says standby it means no current is being absorbed, that is exactly what floating does.

[nj swb]

How can the BMS disconnect the 13.7V float with only two exposed terminals? Without killing loads or disconnecting from the alternator which is a no-go. Most bms are just a switch that sits inline between the neg leg and are purley a catastrophic fail safe. when the bluetooth says standby it means no current is being absorbed, that is exactly what floating does.

At float there is negligible current draw, by the cells, so disconnecting from the alternator isn't an issue. The disconnection happens internally, between the external battery terminal and the cell string. Loads are connected to the external terminals, and remain supplied by the alternator.

I don't know if they do this, but if using FETs to do the switching, the FETs could be ramped from on to off, allowing a smooth transition of the charge current rather than a sudden step change. But I don't believe this would be necessary for disconnection at float.

[Bru9]

At float there is negligible current draw, by the cells, so disconnecting from the alternator isn't an issue. The disconnection happens internally, between the external battery terminal and the cell string. Loads are connected to the external terminals, and remain supplied by the alternator.

I don't know if they do this, but if using FETs to do the switching, the FETs could be ramped from on to off, allowing a smooth transition of the charge current rather than a sudden step change. But I don't believe this would be necessary for disconnection at float.

Well then why is Dicko so worried about floating?.

Macca seems to be saying in standby mode the cell V is 3.58V? that is too high sounds like its being floated.

Personally i think this thread is paid for advertising, the very robust BMS and made in australia gave it away
Can DCS give realworld data plz? Say 30,000km's of outback tracks with no problems regarding vibrations, or 3years of commuting life on the black top with no more than 10% reduction in capacity? That would give some confidence. Their website is a breeding ground of marketing drivel, some realworld vids/reviews would be nice, is that too much to ask for?

There youtube vids disabled comments so that is a red flag they are hiding something. Also one vid i watched they forgot to answer if you need a DCDC...opps. so you actually turn on fans and headlights to get the voltage up for nearly 2grand of stuff?

6X times faster than AGM man!!! Rock on!!!

[Dicko1]

Well then why is Dicko so worried about floating?.

Macca seems to be saying in standby mode the cell V is 3.58V? that is too high sounds like its being floated.

Personally i think this thread is paid for advertising, the very robust BMS and made in australia gave it away
Can DCS give realworld data plz? Say 30,000km's of outback tracks with no problems regarding vibrations, or 3years of commuting life on the black top with no more than 10% reduction in capacity? That would give some confidence. Their website is a breeding ground of marketing drivel, some realworld vids/reviews would be nice, is that too much to ask for?

There youtube vids disabled comments so that is a red flag they are hiding something. Also one vid i watched they forgot to answer if you need a DCDC...opps. so you actually turn on fans and headlights to get the voltage up for nearly 2grand of stuff?

6X times faster than AGM man!!! Rock on!!!

When I started to look into lithium I found that lithium did not go into a float charge. Now a float charge means that the battery has reached its full capacity. It will not accept a current (amperage) but the voltage will remain at a constant predertermined figure ( say 13.7).

I,ve had a hell of a lot of experience with agm and deep cycle batteries as a remote area comms tech who worked on huge solar installations and right down to single panel remote payphones. Know the importance of correct equipment and maintenance for a successful system. That is the simple reason I chose quality , dedicated equipment for my camper and Pajero set up.
I,d like to think that the Renogy battery I have is good quality....time will tell. Huge majority of lithium products come from China. There is good stuff and crap stuff...price can be an indicator but not always relevant to quality. Looking for cheap lithium batteries and purchasing will result in heartbreak in my opinion...same as buying cheap agm batteries..the advertising is complete bullshit but people are suckered into buying something that simply wont last and is nowhere near the claimed capacity.

Like most, I have a lot to learn about lithium but seriously...how much do you really need to know?




It seems that around $800+ is what a good lithium battery sells for . I,ve read of people paying $1400 for the enerdrive 100 which is supposed to be top quality but hasnt turned out that way....its a minefield.


Here is an excellent article about float charge...

https://www.electronicsweekly.com/market-sectors/power/float-charging-lithium-ion-cells-2006-02/

[Maccaman194]

Hi Guys
All good questions about the float etc. I don't really know. The total bank voltages are what I am reading on my Victron BMV 702, and the currents as well. The cell voltages are from the batteries bluetooth data.
ie steady 3.58V per cell and current an amp or 2 in or out of the bank fluctuating as I am driving along once they have recharged. (
Happy to hear any theories about that actually: I just assumed that the internal BMS is controlling that once the max cell voltage is acquired.
At the end of the day I will have to see how it goes. Hopefully by the end of August we will be able to go to WA for my big camping trip and I can try it out properly.
After a previous insulting comment here I am considering not posting any more updates. I have no association with DCS or any other brand - just passing on my experience to you all. I found that comment extremely insulting actually.
So maybe if any of you guys want to hear how it pans out you can PM me.
For those that of you that have posted with questions and advice, I appreciate that. I have taken on board several concerns and taken action to hopefully prevent issues eg insulation and cooling, alternator protector.
So thanks to you all for that.
Macca

[2bad4u]

Hi Guys
All good questions about the float etc. I don't really know. The total bank voltages are what I am reading on my Victron BMV 702, and the currents as well. The cell voltages are from the batteries bluetooth data.
ie steady 3.58V per cell and current an amp or 2 in or out of the bank fluctuating as I am driving along once they have recharged. (
Happy to hear any theories about that actually: I just assumed that the internal BMS is controlling that once the max cell voltage is acquired.
At the end of the day I will have to see how it goes. Hopefully by the end of August we will be able to go to WA for my big camping trip and I can try it out properly.
After a previous insulting comment here I am considering not posting any more updates. I have no association with DCS or any other brand - just passing on my experience to you all. I found that comment extremely insulting actually.
So maybe if any of you guys want to hear how it pans out you can PM me.
For those that of you that have posted with questions and advice, I appreciate that. I have taken on board several concerns and taken action to hopefully prevent issues eg insulation and cooling, alternator protector.
So thanks to you all for that.
Macca

Don't let that put you off. This is by far the friendliest and most helpful forum I have ever belonged to and any comments that get out of hand are shut down pretty quick. There's a forum that is made up of mostly "travelling senior citizens" and it is one of the most argumentative and abusive forums you can find, especially considering their "maturity".

Keep posting up because as you can see, there are plenty of us here that are interested. I'm converting my caravan to lithium in the new year and now, based on your postings, I am considering lithium for my next car which will be in about 12-18mths.

Keep posting away...........

[Jasonmc73]

Hi Guys
All good questions about the float etc. I don't really know. The total bank voltages are what I am reading on my Victron BMV 702, and the currents as well. The cell voltages are from the batteries bluetooth data.
ie steady 3.58V per cell and current an amp or 2 in or out of the bank fluctuating as I am driving along once they have recharged. (
Happy to hear any theories about that actually: I just assumed that the internal BMS is controlling that once the max cell voltage is acquired.
At the end of the day I will have to see how it goes. Hopefully by the end of August we will be able to go to WA for my big camping trip and I can try it out properly.
After a previous insulting comment here I am considering not posting any more updates. I have no association with DCS or any other brand - just passing on my experience to you all. I found that comment extremely insulting actually.
So maybe if any of you guys want to hear how it pans out you can PM me.
For those that of you that have posted with questions and advice, I appreciate that. I have taken on board several concerns and taken action to hopefully prevent issues eg insulation and cooling, alternator protector.
So thanks to you all for that.
Macca

Cheers Macca
I would love to monitor how things pan out as I love the concept, I never considered lithium to be honest, but now i will, thanks to you & I live near Tamborine Mountain DCS as well, so I appreciate your info.
Some of the more interesting i've seen for a while I reckon & great idea.

[nj swb]

After a previous insulting comment here I am considering not posting any more updates. ... I found that comment extremely insulting actually.

I hope it wasn't me.

Ultimately, the internet is accessible to just about anybody who can drive a keyboard, and too many of them have both an over-inflated idea of their own self-worth, and an under-developed set of social skills.

As much as we try to keep this site both civil and light it can be hard for admin and moderators to know where to draw the line on what's an acceptable way to express an opinion without becoming heavy-handed and authoritarian. Some members are much better than others at asking for clarification, or expressing respectful disagreement; similarly, some members cope with criticism, constructive or otherwise, much better than others.

Some years back I stumbled across a term that helps me to cope: "ignoranus". I typed that carefully, it isn't a mis-spelling or a typo - google it. I find it helps water off the duck's back if I categorise some people as such, and move on.

[NTBenny]

Please keep posting updates. I'm very interested in this setup and really keen to see how it goes. I'd like to see how your alternator copes with the charging and heat.

Benny.

[disco stu]

I'll add as well, I would really like to see your continued updates. I think the length of this thread shows how much interest it had created, I've learned heaps from this thread so far

I also hope it wasn't me who said something insulting....

[Maccaman194]

Hi all
Thanks all for those supportive comments. I have actually really appreciated all the informative posts people have made here and the links to more articles etc. It is a steep learning curve, this LiFePO4 stuff. I will keep you all posted. I have a big trip to NT Red Centre, Cobourg etc coming up in a couple of weeks and I will update the forum how it went on my return. Warts and all.
Hopefully the QLD and NT border will stay open for us here in NSW until I leave - fingers crossed.
Cheers
Macca

[Jasonmc73]

Hi all
Thanks all for those supportive comments. I have actually really appreciated all the informative posts people have made here and the links to more articles etc. It is a steep learning curve, this LiFePO4 stuff. I will keep you all posted. I have a big trip to NT Red Centre, Cobourg etc coming up in a couple of weeks and I will update the forum how it went on my return. Warts and all.
Hopefully the QLD and NT border will stay open for us here in NSW until I leave - fingers crossed.
Cheers
Macca

Thanks!!

Appreciated.

[Peterng]

This is a very interesting vid on how to get better longevity out of your lithium batteries...which explains may answer questions raised in this thread.

https://www.youtube.com/watch?v=Yf9N9zBgyB8&t=122s

[disco stu]

Sounds like Dillon from modern family!

Interesting that he brings all of the factors degrading cell life back to internal temperature of the cells during use. Kind of makes one ponder their use in the engine bay

[galaga72]

Hi all
Thanks all for those supportive comments. I have actually really appreciated all the informative posts people have made here and the links to more articles etc. It is a steep learning curve, this LiFePO4 stuff. I will keep you all posted. I have a big trip to NT Red Centre, Cobourg etc coming up in a couple of weeks and I will update the forum how it went on my return. Warts and all.
Hopefully the QLD and NT border will stay open for us here in NSW until I leave - fingers crossed.
Cheers
Macca

Thanks mate for starting this thread with the description of your setup, and to all the other members who have also posted comments/suggestions.
I was planning to replace my current AGM battery (located in the rear seat well) with a lithium battery and utilise my existing Ctek D250S.... now I'll reassess to ensure that it'll provide a sutiable charging solution.