Questions On Lithium Batteries

Long tall John

Long tall John

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T6 Guru
I'm thinking of getting a 100ah lithium battery for a new t6 panel van I'm picking up in about 6 weeks. It will have 2 factory fitted single swivel seats with a diesel heater under one of them.

Electrics will be 49 litre fridge, interior lights, diesel heater, and charging for mobile phones so pretty simple. We want to charge the battery purely by the alternator through dc-dc charger and be able to live off grid for at least 4 days with maybe an hour's driving everyday.

I've read and read and read up on the subject but still a bit confused. I know this is probably more than feasible but any suggestions on which battery, which dc dc charger, and the controller to make sure it doesn't overheat, charge when it's freezing, run dry or overcharge.

I'm looking for something with good proven quality and idiot proof.

I know I can call companies such as travelvolts but before I do that I would like some suggestions on here if you've got any?
 
I have a SuperB epsilon 90ah which is a direct replacement size wise for a LN5 battery (in layman’s terms it fits perfectly under the single passenger seat with factory swivels). I have a sterling 1230 DC charger that charges at 30A. The battery has built in BMS, so no faffing with external management systems. We run a compressor fridge/lights/Webasto/phone chargers etc. We’ve never run it down below 60% charge. We also have solar & mains charger when on EHU, but neither of these are working at the moment due to “technical issues”:rolleyes:. Ideally, you want a dc/dc charger with a lithium profile that can charge at 1/3C, I.e. a charger that can charge the battery at 1/3rd of it’s rated capacity e.g 90Ah battery charges at 30A. This give maximum lifetime of the battery. You can charge lifepo4 batteries at 1C, I.e 90Ah will charge at 90A, but this will shorten the battery life & stress the charging electrics.
 
it can start to get complicated with Lithium.

you will need a low battery disconnect.

and a way to stop any charging if the temp is too low.


Victron do low voltage disconects and there BMV battery monitor has temp as well that can be used as a low temp cut off. (below 0degC)


So:
LBD#1 - to stop low voltage. (discharge + Loads)
BMV power and temp monitor - to switch in LBD#2 (dc -dc or solar charge power low temp cut off)

im going down the victron route myself.

fyi depending on the battery most DC-dc could be used, but its best to use one with a Lithium charge profile . . . . . ill be using the Redarc DC-DC.

@ROMANY TAMPIN has a LifePO4 setup and runs without the above . . . . but keeps the battery in the van above freezing temps.
 
O
Dellmassive said:
it can start to get complicated with Lithiuym.

you will need a low battery disconnect.

and a way to stop any charging if the temp is too low.


Victron do low voltage discobects and there BMV battery monitor has temp as well that can be used as a low temp cut off.


So:
LBD#1 - to stop low voltage. (discharge + Loads)
BMV power and temp monitor - to switch in LBD#2 (dc -dc or solar charge power)

im going down the victron route myself.

@ROMANY TAMPIN has a LifePO4 setup and runs without the above . . . . but keeps the battery in the van above freezing temps.
Click to expand...
or you buy a battery with built in BMS that sorts all that out it’s self.
 
Salty Spuds said:
I have a SuperB epsilon 90ah which is a direct replacement size wise for a LN5 battery (in layman’s terms it fits perfectly under the single passenger seat with factory swivels). I have a sterling 1230 DC charger that charges at 30A. The battery has built in BMS, so no faffing with external management systems. We run a compressor fridge/lights/Webasto/phone chargers etc. We’ve never run it down below 60% charge. We also have solar & mains charger when on EHU, but neither of these are working at the moment due to “technical issues”:rolleyes:. Ideally, you want a dc/dc charger with a lithium profile that can charge at 1/3C, I.e. a charger that can charge the battery at 1/3rd of it’s rated capacity e.g 90Ah battery charges at 30A. This give maximum lifetime of the battery. You can charge lifepo4 batteries at 1C, I.e 90Ah will charge at 90A, but this will shorten the battery life & stress the charging electrics.
Click to expand...
Many thanks for this information. At first glance it does make sense but I will read it a few times as I'm a complete nuby with electrics. I've read Dellmassives thread on lifepo4 many times and still getting my head around it!!!
I think I'll need a victron
Lithium SuperPack with a dc dc charger and probably a couple of fuses?!
 
i went for this battery. ( the victron battery was just too expensive)

================================

just bagged myself one of these . . . . . .

Download Data Sheets - Lithium Werks

Valence GREEN Lithium LiFePO4 BATTERY 138Ah 12.8v with internal BMS
Sold with 6 MONTH WARRANTY !!

rated at 4000 cycles plus (logs show only 400 cycles used)

12v 138Ah LifePO4 (thats the equivalent on of almost 3x100aH AGM`s with 50% DOD)

Dimensions: 31cm wide * 22cm tall * 17cm back to front. Can be installed on its side.Charged/discharged to 80% every day they would last more than 12 years with No maintenance.

it should fit under drivers seat on its side. . . . .

They are ideal as leisure batteries (charging direct from alternator or solar) - ill use DC-DC/Solar with Lifepo4 charging profile.

These will discharge at up to 150 amps continuously at near constant voltage. This makes them as good in the real world as two lead acid gel batteries of the same capacity which would only last a fraction of the life - 150A discharge rate with no sag !!! - time to get the big inverter back out !!!

22-jpg.50559



ill make up my own USB/RS485 for the built in BMS to check and test the battery . . . . .



*********************************

U-Charge® XP for 12V, 24V, 36V, 48V up to 1kV Battery


.


.




.



.



.



.


Discharge Temperature -10 °C to 50 °C
Charge Temperature 0 °C to 45 °C
Self Discharge @ 25 °C < 2% per month
Specific Energy 92 Wh/kg
Energy Density 150 Wh/l
Voltage (nominal) 12.8 V
Capacity @ C/5, 25 °C (typical) 118 Ah
Energy 1.51 kWh
Discharge Cont./Peak (30 sec) 150 A / 300 A
Discharge Cutoff Voltage 10 V
Recommended Charge Voltage 14.6 V
Charge Float Voltage Range 13.8 - 14.6 V
Recommended Charge CCCV ≤ 59 A to 14.6 V
E



.....


Height (excluding bolts) 225 mm 8.86”
Width 172 mm 6.77”
Length 260 mm 10.23”
Weight 16.3 ± 0.1 kg 35.8 lbs
Cell Configuration 4IFpR27/66-36
Terminal Hardware M8 x 1.25
Terminal Torque 25 Nm 222 in-lbs
Plastic Case Flame Retardant
IP Rating IP56



=====================
 
Last edited:
Long tall John said:
This is where I get confused as I can't find the ah for it on the spec sheet. I think it's on the higher end of my budget but I would only have to buy the DC DC charger to run it off my alternator?
Click to expand...
It says 90ah, which can be discharged to 80%, which would be the equivalent of a 144ah AGM battery as that can only be discharged to 50%. It looks great, but £1500 is just too much for me, given that my current setup works great for me. The 138ah battery mentioned by @Dellmassive would be the equivalent of a 220ah AGM and is a lot cheaper, but looks like it would need an external battery management system, as well as a different charger
 
andys said:
It says 90ah, which can be discharged to 80%, which would be the equivalent of a 144ah AGM battery as that can only be discharged to 50%. It looks great, but £1500 is just too much for me, given that my current setup works great for me. The 138ah battery mentioned by @Dellmassive would be the equivalent of a 220ah AGM and is a lot cheaper, but looks like it would need an external battery management system, as well as a different charger
Click to expand...
Yes £1500 is way too much for my use really and the 138ah does seem a good buy.
 
More info from that valence..

Dedicated charger not reqd...


Built in bms.... but external low volt and low temp cut off recommended as you will not using the OEM master system bms for long life. (Internal bms has 10v cutoff, but 11v cutoff is recommended)...



Features
  • >4000 cycles (80% DOD)
  • Exceptional voltage stability
  • Standard voltage range from 12V – 1000V
  • Maintenance free
  • Automatic Intra and Inter module balancing
  • Can be charged using most standard lead acid chargers
  • Communication of monitored data via Battery Management System (BMS)
  • Rugged mechanical design
  • Flame retardant plastics
  • LED battery status indicator
  • Carrying Straps (U24, U27, UEV models)
  • Manufactured in standard BCI sizes

So standard dc-dc charger should be ok.

But I'm adding in low volt disconect and possibly low temp too.
 
Dellmassive said:
More info from that valence..

Dedicated charger not reqd...


Built in bms.... but external low volt and low temp cut off recommended as you will not using the OEM master system bms for long life. (Internal bms has 10v cutoff, but 11v cutoff is recommended)...



Features
  • >4000 cycles (80% DOD)
  • Exceptional voltage stability
  • Standard voltage range from 12V – 1000V
  • Maintenance free
  • Automatic Intra and Inter module balancing
  • Can be charged using most standard lead acid chargers
  • Communication of monitored data via Battery Management System (BMS)
  • Rugged mechanical design
  • Flame retardant plastics
  • LED battery status indicator
  • Carrying Straps (U24, U27, UEV models)
  • Manufactured in standard BCI sizes

So standard dc-dc charger should be ok.

But I'm adding in low volt disconect and possibly low temp too.
Click to expand...
It looks like the Valence Green & SuperB Epsilon are both made by Lithium Werks, which is odd.
 
Really?

I cant see the link? Or connection.
 
Last edited:
The Valence Green ones are technically used, from used electric cars and the like aren’t they? That’s why they’re cheap (relatively!) and only have a six month warranty?
 
The ebay ones are ex medical UPS ones that apparently have to be replaced every so often.... they have had 400 cycles... a ording to the Internal bms. (Sorting out the software to confirm this..... windowsXP and usb to rs485 lead)



So yes used..... but nearly new with respect to 4000+ cycles life span.

New they are £1500-£2000....
 
Dellmassive said:
The ebay ones are ex medical UPS ones that apparently have to be replaced every so often.... they have had 400 cycles... a ording to the Internal bms. (Sorting out the software to confirm this..... windowsXP and usb to rs485 lead)



So yes used..... but nearly new with respect to 4000+ cycles life span.

New they are £1500-£2000....
Click to expand...

Yes, could be a good value option. Good idea to confirm the number of cycles though, let us know what you find!
 
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