Lithium battery install

Eugene Rider

2016 Unity TB
I have been asked to supply pictures and progress about my lithium battery install.
I picked up my "install" kit last Thursday from AM Solar.
I only have two of the batteries, the other two are coming.
I'm installing 4 Victron 12.8v/90ah batteries, Victron 3000 watt inverter with color monitor and a Victron BlueSolar charge controller. (according to AM Solar, more amps will get threw, 10-30% more).
Lots of relays and wiring.
I hope to install all 4 batteries and lynx distributor 1000 in the compartment behind the coach door, the now battery compartment wii hope in inverter along with wiring a relays.
Sleeping has been marred with waking up, thinking about all the work ahead.
I'm also installing a National 270 amp alternator as I didn't get a generator with my Unity TB.
 

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alichty

2014 LTV Unity TB
This looks serious :popcorn: <pulling up chair to watch>.......
 

Peter Tourin

2020 Unity RL, ex 2012 Unity MB
Me too - this looks like a really interesting project. You sure went for the nice stuff <g>...
 
Peter,
What will be your total battery weight for the four? Compare to your original weight for 2 lead acids. Make lots of photos.
Thanks
 

Peter Tourin

2020 Unity RL, ex 2012 Unity MB
It's not my project, I'm just lurking and gabbing <g>... But the Victron batteries aren't particularly light,it looks like they're around 33 lbs each. I think my 2 stock batteries were 47 lbs each. But there's way more capacity there. Stock batteries would be around 180 aH total, and if you use the 50% rule to keep them from degrading quickly, you have 90 aH usable capacity. Four 90 aH lith batteries is 360 aH total, but you could use 80% of that, so you have 325 aH of usable capacity. Plus you can charge/discharge them at a high rate. If I understand the original post, he's adding an extra 270 amp alternator - if that's true, he can pull the battery bank way down and then recharge by driving around for somewhat more than an hour. That's a lot of gain.
 

Eugene Rider

2016 Unity TB
It's not my project, I'm just lurking and gabbing <g>... But the Victron batteries aren't particularly light,it looks like they're around 33 lbs each. I think my 2 stock batteries were 47 lbs each. But there's way more capacity there. Stock batteries would be around 180 aH total, and if you use the 50% rule to keep them from degrading quickly, you have 90 aH usable capacity. Four 90 aH lith batteries is 360 aH total, but you could use 80% of that, so you have 325 aH of usable capacity. Plus you can charge/discharge them at a high rate. If I understand the original post, he's adding an extra 270 amp alternator - if that's true, he can pull the battery bank way down and then recharge by driving around for somewhat more than an hour. That's a lot of gain.
Very close 31 pounds
 

jackfish

Active member
325 AH of usable capacity in Fullriver AGM batteries would weigh 426 lbs. 426 minus 124 equals 302 pounds saved. Now what is the typical cost of the lithiums? Up to $1800 for the Fullrivers, and then one would have to find the room for them (I guess Gamma1966 did).
 
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Boxster1971

2012 Sprinter 3500 Ext
Eugene - that looks like a great project. I join those waiting to hear more on how it goes together. How do you plan to deal with freezing temps impacting charging ability?
 

Eugene Rider

2016 Unity TB
325 AH of usable capacity in Fullriver AGM batteries would weigh 426 lbs. 426 minus 124 equals 302 pounds saved. Now what is the typical cost of the lithiums? Up to $1800 for the Fullrivers, and then one would have to find the room for them (I guess Gamma1966 did).
These are $980 per battery, so $3940. I'm spending the money that I saved on not having a generator. With 3 more solar panels for a total of 5, the 270 amp alternator and all the goodies, I'm going to be pushing $12k. But, it's a hobby so it priceless.
 

Eugene Rider

2016 Unity TB
325 AH of usable capacity in Fullriver AGM batteries would weigh 426 lbs. 426 minus 124 equals 302 pounds saved. Now what is the typical cost of the lithiums? Up to $1800 for the Fullrivers, and then one would have to find the room for them (I guess Gamma1966 did).
These are $980 per battery, so $3940. I'm spending the money that I saved on not having a generator. With 3 more solar panels for a total of 5, the 270 amp alternator and all the goodies, I'm going to be pushing $12k. But, it's a hobby so it priceless.
 

Peter Tourin

2020 Unity RL, ex 2012 Unity MB
I'll be interested to hear how that dedicated alternator works. I've watched my batteries charge and graphed what I see - for both the M-B alternator and the lithium charger. They both work about the same - let's say I'm driving and my batteries are down to 50%. I switch on the alternator (that is, I close the isolator so the alternator output is connected to the house batteries) and I immediately see about 80 amps charging current. But that current steadily goes down as the battery voltage climbs and the batteries get nearer to full charge. By the time they're almost charged, I see the voltage start to go up very quickly and the current drop very quickly. At that point I end the charge cycle - when the current drops to around 20 amps or 10% of my 200 Ah capacity.

This was a surprise, because all the discussions of lithium chargers describe them as CCCV (constant current/constant voltage) chargers, with a fixed max. voltage - 60 amps and 14.6 volts in the case of my chargers. The graphs they show indicate that they'll put out the full rated current until the batteries are nearly full, and during that time the voltage will climb until it's around the max. voltage. Then the charger will hold that max. voltage and the current will drop until you stop charging. But that's not what I see when I watch my batteries charge - neither with the charger nor with the stock M-B alternator.
 

avanti

2014 GWV Legend 3500 I4
Make sure your Balmar regulator is properly programmed for lithium (the folks at Nations' have good advice). If set up properly, I predict that you will be very pleased indeed with this setup. I certainly am with mine (albeit with AGM). There will be no comparison with using the table droppings from your Sprinter's power system.
 

Peter Tourin

2020 Unity RL, ex 2012 Unity MB
If my stock alternator is table droppings, then I'd hate to say what the charger is - not even gravy drips <lol>... I'm very surprised that with a new lith-specific 60 amp charger the most charging current I've seen is around 45 amps or so. Simple me - I thought the ratings meant something <g>... So even with just the stock alternator, I charge faster when driving then on shore power. Of course, I could get a larger charger - I was afraid that if I did that, I could overload the 30A campground service if I was charging and running A/C and who knows what else... But when you charge using the dedicated alternator and Balmer regulator, does your charging current stay high as the alternator pulls the battery voltage up, or do you see the current drop like I do?
 

avanti

2014 GWV Legend 3500 I4
But when you charge using the dedicated alternator and Balmer regulator, does your charging current stay high as the alternator pulls the battery voltage up, or do you see the current drop like I do?
Well, as I said, I am running AGM, not Li, so my experience is not overly relevant wrt charge profile. But, starting north of 200 amps, I can afford some current drop. My only real point is that you get a LOT more amps from one of these alternators, and the raw rating of your Sprinter's alternator is not a good predictor of its behavior, at least in late-model units.
 

Davydd

Well-known member
The most current you are going to get from shore power or an Onan generator I believe is a theoretical maximum of 120A. I typically see about 100 to 105A on shore power. With your engine alternator you are not going to get much as it has to satisfy your engine and chassis first. I don't know what that is but in my previous Bs it wasn't much and I don't think charged as fast as shore power. I really had no way to monitor it. With a dual alternator like a 270A Nations your initial current will be close to what it is rated well over 200A but will drop off with heat and not necessarily because your battery is reaching full SOC. I think your BMS controls that. The Balmar has a temperature sensor to control the amperage output. The Nations alternator dropped off significantly after 30 minutes to an hour but usually you recharge an overnight stay in that time with li-ion batteries. Advanced RV determined it wasn't robust enough for those running the rooftop air conditioning continuously while driving which some of their southwest customers were desiring. They were failing under that kind of load So they went to a Delco Remy 320A alternator. So far I am not seeing any significant current drop off after an hour's driving. It settles in at about 280A delivery. I had to deliberately run my battery SOC down enough to be able to drive an hour on the steady speed 50 mph Natchez Trace National Scenic Parkway to test that.
 

wade5979

New member
Peter,

When charging and controlling that charge with the Magnum Energy charger and battery monitor on shore power I'm seeing over 100 amps when battery bank is around 40% SOC. At about 90% SOC volts are at 13.4 to 13.6 and amps down to 50. At around 97% current drops to 20 amps volts are 14.2. During the next 10 to 20 minutes voltage continues to climb until it starts bumping back and forth between 14.4 to 14.6. When I sees this back and forth for about 5 minutes it then stops all charging and goes into sleep mode until I reach 40% SOC again or the shore power is unplugged and plugger back in again starting the cycle over again.

For alternator i'm using the Victron battery monitor to open a solenoid when SOC is at about 90% and close at around 60%. I find these values usually give me a close to full charge whenever we stop driving after about 2 hours. I normally see around 80 amps when the relay closes and 40 or less when it opens. Don't have enough confidence in the MB charge system to push it closer to full SOC.

I also control the solar charge with a Victron battery monitor and allow the solar to bring the banks on up to 95% and it usually open that solenoid around 15amps on a sunny day
 

Peter Tourin

2020 Unity RL, ex 2012 Unity MB
Wow Davydd, that's a bg alternator! - with my 200 Ah system, I could do a full charge in about 1-1/4 hours. That'd be nice! I recharge quicker from the alternator than from the charger, but it's only a 60 amp charger, and the current output starts dropping pretty quickly as the battery voltage starts to climb. If I did it again, I might go to a 70 or 80 amp charger instead. But it's good enough for the kind of camping we do - we tend to drive a lot and not stay for weeks at a time, so recharging isn't hard for us.

Wade, it sounds like you're seeing more or less what I'm seeing. I define 100% SOC as over 13.4 volts and below 10% or 20 amps. So when I reach 100% SOC on the monitor, I'm seeing the voltage climb to 13.8 or 14.0 volts as the current drops to 20 amps. This is the beginning of the knuckle at the top of the charging curve - if I leave charging connected after the monitor reads 100%, in 10 minutes or so I'll be seeing 14.2 or 14.3 volts and current dropping rapidly down to 10 amps and below. So by the time the charger pushes the voltage up to near its rated 14.6 max voltage, the current is down to a few amps. SmartBattery says it's OK to charge up to 14.6 but I'm choosing to be cautious here - I don't push it too hard, as I have enough battery for the kind of camping we generally are doing. So much for those nice neat CCCV graphs of how these chargers behave - mine sure doesn't look anything like those graphs!
 

Scarecrow

2017 LTV Unity Murphy Bed
These are $980 per battery, so $3940. I'm spending the money that I saved on not having a generator. With 3 more solar panels for a total of 5, the 270 amp alternator and all the goodies, I'm going to be pushing $12k. But, it's a hobby so it priceless.
This has to be the FIRST time I've seen anybody mention actually spending $12,000 and "priceless" in the same sentence! :thumbup:

Good luck! I'm envious... for some reason.
 

Bone Head

2014 LTV Unity MB
This has to be the FIRST time I've seen anybody mention actually spending $12,000 and "priceless" in the same sentence! :thumbup:

Good luck! I'm envious... for some reason.
Boy Howdy!!
 

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