Thats what I've got
Lithium LifePo4 12v Batteries - Time For An Upgrade?
- Thread starter Dellmassive
- Start date
Thats what I've got
So your still not convinced that Lithium Lifepo4 is the way to go . . . . . . . ?
check out this vid from our chums over at Sterling Power
watch the intro . . . . . and test setup.
then if your impatient skip to 9.35mins for results . . . . you will be surprised at the data results.
.
and to backup the results heres Wills take on it . . . . . .
.
check out this vid from our chums over at Sterling Power
watch the intro . . . . . and test setup.
then if your impatient skip to 9.35mins for results . . . . you will be surprised at the data results.
.
and to backup the results heres Wills take on it . . . . . .
.
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this Lifepo4 looks similar to the TN?
Note the lack of volt sag when drawing 1500w via the Cotek boiling a kettle.
.
Note the lack of volt sag when drawing 1500w via the Cotek boiling a kettle.
.
similar test with the Relion
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 !!!
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
=====================
FYI the above green batteries are the V2 versions.
there are also the Black V1 versions. . . . .
greens are 138ah, blacks 130ah.
they have different BMS connectors.
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 !!!
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
=====================
FYI the above green batteries are the V2 versions.
there are also the Black V1 versions. . . . .
greens are 138ah, blacks 130ah.
they have different BMS connectors.
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Battery is in.... all looking good so far.
Ta. Looks good and await news on performance with interest.
Odd statement in Hymers new publicity blurb for the DuoCar S:
“The Hymer DuoCar S is also the perfect companion for adventures off the beaten track. This is ensured by the self-sufficiency concept featuring a diesel heater, a large 93-litre fuel tank and the optional Hymer Smart-Battery-System. This innovative energy system combines the superb performance of lithium batteries with the low costs of conventional lead batteries. The system stores the energy in both batteries in parallel, and the charge status is controlled in an intelligent way. This in-creases efficiency and makes you self-sufficient for a much longer period of time – up to 9.6 days at the typical rate of use.”
I assume this means lithium batteries that cost the same as AGM and not a combination of lead and lithium linked up in parallel?
Odd statement in Hymers new publicity blurb for the DuoCar S:
“The Hymer DuoCar S is also the perfect companion for adventures off the beaten track. This is ensured by the self-sufficiency concept featuring a diesel heater, a large 93-litre fuel tank and the optional Hymer Smart-Battery-System. This innovative energy system combines the superb performance of lithium batteries with the low costs of conventional lead batteries. The system stores the energy in both batteries in parallel, and the charge status is controlled in an intelligent way. This in-creases efficiency and makes you self-sufficient for a much longer period of time – up to 9.6 days at the typical rate of use.”
I assume this means lithium batteries that cost the same as AGM and not a combination of lead and lithium linked up in parallel?
quote:
Thanks @travelvolts . Its suddenly (TN LiFepo4 battery) starting to look very appealing. Do you happen to know if the battery in built protection will prevent it from being charged if the temperature drops to zero degrees. The blurb mentions over temperature protection but not low temp.
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No . . . The TN needs external low temp protection the same as most Lifepo4 batterys (could just be a manual shut off switch, switch off when its cold and switch back on when it warms up a bit)
But if your forgetfull like me you might need a installed option . . . .
These lithium's charge FAST and suck in all the current they can get. . . . . currently charging a 138Ah Vallence with 2x 15A chargers in parallel !!!! and its taking the lot! its drawing 30Amps but could take 50A or 70A if it was available.
so im cautious that in future when its cold that the battery will want to draw 50+ Amps from the DC-DC and may damage the battery if the cell temps are below 0,1,2,3,4,5 deg C.
Some of the more expensive Lifepo4 batteries have internal heaters to extend the temp range . . . . . but these are £1500 and up each.
another option that I've seen is to use a 12v heatpad and thermostat - but that just seems to be a waist of energy to me . . . . . to waste energy to keep the bayttery temp above 0degC when its not beinbg used . . . ie all night.
i think it makes more sense to fit a low temp cut off that disconnects the charging current untill the temp rises above the cutoff point - but leaving the load side connected as this would aid internal heating of the battery when a current is being drawn.
I've gone with the victron solution. . . . . a main 100A LBD for the loads . . . . and a second 60A LBD on the charge source (50A dc-dc) that will be switched on/off via the temp control on the BMV battery monitor. . . . . . . so the main 100A LBD will shutoff if the voltage drops to 11.5v and the 60A LBD will be temp controlled to shutoff below 4degC.
another option I've seen is just a SCR (relay) on the supply/charge side that is switched via a basic 12v temperature circuit/thermostat . . . . cheap and simple (but havent seen this in reality yet)
Thanks @travelvolts . Its suddenly (TN LiFepo4 battery) starting to look very appealing. Do you happen to know if the battery in built protection will prevent it from being charged if the temperature drops to zero degrees. The blurb mentions over temperature protection but not low temp.
*******************************************************************************************************
No . . . The TN needs external low temp protection the same as most Lifepo4 batterys (could just be a manual shut off switch, switch off when its cold and switch back on when it warms up a bit)
But if your forgetfull like me you might need a installed option . . . .
These lithium's charge FAST and suck in all the current they can get. . . . . currently charging a 138Ah Vallence with 2x 15A chargers in parallel !!!! and its taking the lot! its drawing 30Amps but could take 50A or 70A if it was available.
so im cautious that in future when its cold that the battery will want to draw 50+ Amps from the DC-DC and may damage the battery if the cell temps are below 0,1,2,3,4,5 deg C.
Some of the more expensive Lifepo4 batteries have internal heaters to extend the temp range . . . . . but these are £1500 and up each.
another option that I've seen is to use a 12v heatpad and thermostat - but that just seems to be a waist of energy to me . . . . . to waste energy to keep the bayttery temp above 0degC when its not beinbg used . . . ie all night.
i think it makes more sense to fit a low temp cut off that disconnects the charging current untill the temp rises above the cutoff point - but leaving the load side connected as this would aid internal heating of the battery when a current is being drawn.
I've gone with the victron solution. . . . . a main 100A LBD for the loads . . . . and a second 60A LBD on the charge source (50A dc-dc) that will be switched on/off via the temp control on the BMV battery monitor. . . . . . . so the main 100A LBD will shutoff if the voltage drops to 11.5v and the 60A LBD will be temp controlled to shutoff below 4degC.
another option I've seen is just a SCR (relay) on the supply/charge side that is switched via a basic 12v temperature circuit/thermostat . . . . cheap and simple (but havent seen this in reality yet)
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Low Temp Lifpo4 battery disconnect :
heres a few cheap ways you can add temperature cut off for lithium charging. (for the charging side of the system) (loads can be connected via a separate LBD as required)
below are some cheap 12v temp controlled relays . . . . the idea would be that you would get a separate 12v SCR (high current relay) for whatever Amps your charging system can deliver . . . .?
say you have a 20Amp DC-DC charger . . . . then get a 25A or above SCR . . . and put it in between the Lifepo4 and DC-DC charger.
then you you use your ignition feed to power one of the below Temp controlled relays below . . . . which in turn would power the larger SCR.
SO Ignition -> Temp Control Relay -> Large SCR -> charge battery
OR - if you have a DC-DC charger that needs an ignition/run feed you can use the temp relay to to interrupt this feed stop the DC-DC from charging.
this way the battery is isolated from the charger until the ignition/engine run is switched on (stops any power drain) . . . . and then will only engage if the temp is above the 5degC . . . and the circuit would only be powered when the ignition/engine running to stop and power drain from your battery.
I've not set this up and tested it yet . . . . . . . .but it looks right in my head.?
and below is a couple of examples of the SCR . . . . a 50A and 100A version.
.
heres some more info . . . .
.
.
lol . . . . looking like he had the similar idea (but just on solar) =]
.
heres a few cheap ways you can add temperature cut off for lithium charging. (for the charging side of the system) (loads can be connected via a separate LBD as required)
below are some cheap 12v temp controlled relays . . . . the idea would be that you would get a separate 12v SCR (high current relay) for whatever Amps your charging system can deliver . . . .?
say you have a 20Amp DC-DC charger . . . . then get a 25A or above SCR . . . and put it in between the Lifepo4 and DC-DC charger.
then you you use your ignition feed to power one of the below Temp controlled relays below . . . . which in turn would power the larger SCR.
SO Ignition -> Temp Control Relay -> Large SCR -> charge battery
OR - if you have a DC-DC charger that needs an ignition/run feed you can use the temp relay to to interrupt this feed stop the DC-DC from charging.
this way the battery is isolated from the charger until the ignition/engine run is switched on (stops any power drain) . . . . and then will only engage if the temp is above the 5degC . . . and the circuit would only be powered when the ignition/engine running to stop and power drain from your battery.
I've not set this up and tested it yet . . . . . . . .but it looks right in my head.?
and below is a couple of examples of the SCR . . . . a 50A and 100A version.
.
heres some more info . . . .
.
.
lol . . . . looking like he had the similar idea (but just on solar) =]
.
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Low Battery Disconnect - Battery Protect :
these are basically self contained units that are ready to be fitted.
the are wired inline with the battery positive feed (on the load side) just after the fuse and are normally programmable (the low volt disconnect point).
you would set the low voltage cutoff as specified by your battery manufacturer and thats that.... . . . .
when the battery voltage drops to the set-point for a set duration the internal relay disconnects the battery from any loads. . . . . . . (untill the voltage rises again after being charged)
some solar controllers have this feature built into them . . . . but they are normally current limited (fairly low, like 10A-30A) so thye below examples are for 65A and 100A examples.
Not sure why the duritre one is listed so pricey . . . . but the victron units below are more average priced.
heres the victron demo . . . . .
.
and . . . .
.
these are basically self contained units that are ready to be fitted.
the are wired inline with the battery positive feed (on the load side) just after the fuse and are normally programmable (the low volt disconnect point).
you would set the low voltage cutoff as specified by your battery manufacturer and thats that.... . . . .
when the battery voltage drops to the set-point for a set duration the internal relay disconnects the battery from any loads. . . . . . . (untill the voltage rises again after being charged)
some solar controllers have this feature built into them . . . . but they are normally current limited (fairly low, like 10A-30A) so thye below examples are for 65A and 100A examples.
Not sure why the duritre one is listed so pricey . . . . but the victron units below are more average priced.
heres the victron demo . . . . .
.
and . . . .
.
That all seems a bit Heath Robinson to me @Dellmassive. Can you not get this functionality built into the battery BMS?
Yes on a £1500 battery...
No on a £500 battery.
Saying that.... the valence I have has an internal BMS.... which has an emergency 10v low volt disconect, but no low temp disconect. The internal BMS is mainly for ballancing the internal cells.... the 10v shut down is last ditch attempt to save the battery.
Its recommended cutoff is 11.5v and not to be charged below 0degC.
It looks like the £1500 -10degC batteries have internal heaters that use the batteries own power to keep themselves warm.... but you pay for these extra features.
It's the same for the low volt disconect... all the batterys have a very low shutoff.... some down to 8v !!! But again it's a saftey feature and will soon kill the cells if you regularly run them that low...... the recommended 11v ish cutoff will ensure the battery will last a long time and keep the battery within its charge/discharge envelope...
Run them outside the envelope and they die very quickly. A Lifepo4 battery can be killed dead after just one total discharge..... which is why they all have low volt disconnects, but that's just the emergency case and should not be used as an every day feature.
Its case of pay the £1500+ for one of the batteries that have it all built in.
Or.
Be very vigilant on your usage and monitor everything so you can manually disconect the battery.
Or
Go for the cheaper £500 battery option and add any of the above 3rd party work arounds..
@ROMANY TAMPIN has a LIFOS lifepo4 and doesn't have either of the above disconnects...... but he has the battery installed inside the van in the living area keeping it above temp.... and has battery monitors to keep any eye on the voltage.....plus solar etc..... to ensure he doesn't drop low.
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Something that springs to mind, albeit in my limited knowledge capacity. But is the temp sensing relay just measuring ambient air temperature. It's just, being considerably more dense, the core of the battery may take some time to come up to a temperature above freezing. Even though the surounding air temp could be up in a matter of minutes, from engine or auxiliary cabin heater start up. If that makes sense.
The victron solution has either a small module that "sticks" on the side of the battery . . . . or a second option that has a battery eyelet that goes on the battery terminal itself.
so yes you are correct. if you used one of the above temp sensor relays you would need to stick the temp probe to the battery casing or similar.
and again to deal with the thermal soak vs ambient air temp you would set the disconnect at say 5degC to keep yourself above the 0degC cutoff.
a few examples for victron temp sensors...
....
in answer to @Deaky valid question, i thought i would check some stats:
LBD? - Low Battery Disconnect
LTD? - Low Temp Disconnect
The findings below are interesting . . . .
All of the batteries listed have the emergency low battery disconnect ranging from 8v-11.6v to protect themselves . . . . . but all recommend a low voltage disconnect from 11-12v. (that imply that the higher voltage disconnect will extend the life of the battery and the built in emergency disconnect is just a final safety device as below this point the cells are permanently damaged).
None of the batteries have low temp charging disconnects . . . but all have high temp safety cutoffs . . . .they all clearly state the charging parameters, and state the 0degC limit. That is except for the Relion & Epsilion that have internal heaters and are able to charge safety down to -10degC (albeit at a reduced rate). This seems to me a bit of a sales pitch . . . . they (manufacturers) know that charging below 0degC will damage the battery . . . . but the info is buried deep in the spec sheets. . . . . i wonder how many people will be killing there very expensive battery this winter due to this little bit of info? (remember these batteries will suck in 30/50/70/100 Amps when they charge . . . even from 90% full. Thats not good going into a frozen lithium pack/cell)
stats below and links to tech specs . . . . . . . . (check for yourself)
and if anyone has any other makes they want to mention, ill add them to the list.
*********************
Victron Victron SuperPack, (https://www.victronenergy.com/upload/documents/Datasheet-12,8V-Lithium-SuperPack-EN.pdf)
LTD - NO (Charge: +5°C to +45°C, Discharge: -10°C to +50°C )
LBD - NO - ?v (emergancy shutdown)(The internal switch will disconnect the battery in case of over discharge, over charge or high temperature.)
*********************
TN (https://www.batterymegastore.co.uk/amfile/file/download/file_id/451/product_id/8649/)
LTD - NO (Charge Temperature 0℃ to 45℃(32℉ to 113℉) @60±25% Relative Humidity)
LBD - NO - 10V (emergancy shutdown)
*********************
Relion - (https://www.alpha-batteries.co.uk/media/catalog/product/r/e/reliondata_6.pdf)
LTD - YES - (has heater) Discharge -20°C to +60°C, charge -20°C to +45°
LBD - NO - 8V (emergancy shutdown) (Recommended Low Voltage Disconnect 11 V)
*********************
LifOS - (Technical Information - LiFOS)
LTD - NO (Operating temperature in charge : 0°C à +60°C)
LBD - NO - Recommended Low Volt Disconnect 11.6V / reconnect @ 12.8V (@ROMANY TAMPIN take note your battery lowest voltage is listed at 11.6V . . . dont let it drop below that)
*********************
Valence U27-12XP (Download Data Sheets - Lithium Werks)
LTD - NO (Operating temperature in charge : 0°C à +45°C)
LBD - NO - 10V (emergancy shutdown)
*********************
PowerTech - Lithium-Ion Battery 12V – 100Ah – 1.28kWh – PowerBrick+ (Lithium-Ion Battery 12V - 100Ah - 1.28kWh - PowerBrick+ / LiFePO4)
LTD - NO (Operating temperature in charge : 0°C à +60°C)
LBD - NO - 10V (emergancy shutdown)
*****************************
Ultramax - 100Ah 12V LiFePO4 LITHIUM BATTERY (https://www.ultramax.co.uk/media/catalog/product/pdf//s/l/slaumxli100-12-tech_3.pdf)
LTD - NO (Charge Tempreture 0°C-45°C(32°F-113°F))
LBD - NO - 10V (emergancy shutdown)
************************
Epsilon SB12V1200Wh-M (https://www.super-b.com/content/fil.../Epsilon/Super_B_Epsilon_Manual_English_1.pdf)
Super B
LTD - YES - (has heater) Discharge -20°C to +60°C, charge -10°C to +45° (When temperature is < 0ºC or > 45ºC performance will be degraded.)
LBD - NO - 8V (emergancy shutdown)
***************************
LBD? - Low Battery Disconnect
LTD? - Low Temp Disconnect
The findings below are interesting . . . .
All of the batteries listed have the emergency low battery disconnect ranging from 8v-11.6v to protect themselves . . . . . but all recommend a low voltage disconnect from 11-12v. (that imply that the higher voltage disconnect will extend the life of the battery and the built in emergency disconnect is just a final safety device as below this point the cells are permanently damaged).
None of the batteries have low temp charging disconnects . . . but all have high temp safety cutoffs . . . .they all clearly state the charging parameters, and state the 0degC limit. That is except for the Relion & Epsilion that have internal heaters and are able to charge safety down to -10degC (albeit at a reduced rate). This seems to me a bit of a sales pitch . . . . they (manufacturers) know that charging below 0degC will damage the battery . . . . but the info is buried deep in the spec sheets. . . . . i wonder how many people will be killing there very expensive battery this winter due to this little bit of info? (remember these batteries will suck in 30/50/70/100 Amps when they charge . . . even from 90% full. Thats not good going into a frozen lithium pack/cell)
stats below and links to tech specs . . . . . . . . (check for yourself)
and if anyone has any other makes they want to mention, ill add them to the list.
*********************
Victron Victron SuperPack, (https://www.victronenergy.com/upload/documents/Datasheet-12,8V-Lithium-SuperPack-EN.pdf)
LTD - NO (Charge: +5°C to +45°C, Discharge: -10°C to +50°C )
LBD - NO - ?v (emergancy shutdown)(The internal switch will disconnect the battery in case of over discharge, over charge or high temperature.)
*********************
TN (https://www.batterymegastore.co.uk/amfile/file/download/file_id/451/product_id/8649/)
LTD - NO (Charge Temperature 0℃ to 45℃(32℉ to 113℉) @60±25% Relative Humidity)
LBD - NO - 10V (emergancy shutdown)
*********************
Relion - (https://www.alpha-batteries.co.uk/media/catalog/product/r/e/reliondata_6.pdf)
LTD - YES - (has heater) Discharge -20°C to +60°C, charge -20°C to +45°
LBD - NO - 8V (emergancy shutdown) (Recommended Low Voltage Disconnect 11 V)
*********************
LifOS - (Technical Information - LiFOS)
LTD - NO (Operating temperature in charge : 0°C à +60°C)
LBD - NO - Recommended Low Volt Disconnect 11.6V / reconnect @ 12.8V (@ROMANY TAMPIN take note your battery lowest voltage is listed at 11.6V . . . dont let it drop below that)
*********************
Valence U27-12XP (Download Data Sheets - Lithium Werks)
LTD - NO (Operating temperature in charge : 0°C à +45°C)
LBD - NO - 10V (emergancy shutdown)
*********************
PowerTech - Lithium-Ion Battery 12V – 100Ah – 1.28kWh – PowerBrick+ (Lithium-Ion Battery 12V - 100Ah - 1.28kWh - PowerBrick+ / LiFePO4)
LTD - NO (Operating temperature in charge : 0°C à +60°C)
LBD - NO - 10V (emergancy shutdown)
*****************************
Ultramax - 100Ah 12V LiFePO4 LITHIUM BATTERY (https://www.ultramax.co.uk/media/catalog/product/pdf//s/l/slaumxli100-12-tech_3.pdf)
LTD - NO (Charge Tempreture 0°C-45°C(32°F-113°F))
LBD - NO - 10V (emergancy shutdown)
************************
Epsilon SB12V1200Wh-M (https://www.super-b.com/content/fil.../Epsilon/Super_B_Epsilon_Manual_English_1.pdf)
Super B
LTD - YES - (has heater) Discharge -20°C to +60°C, charge -10°C to +45° (When temperature is < 0ºC or > 45ºC performance will be degraded.)
LBD - NO - 8V (emergancy shutdown)
***************************
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The testing and BMS monitor is done, the battery looks like a good one.
here is the battery as delivered. . . . it shows 12.8V, but it actually almost flat. (cell @ 3.2v)
this is the battery BMS diagnostic lead i made up . . . . .
and this is the 150A inline power meter monitoring whats going on . . .
i used a Victron 12/15A charger on lithium mode to start charging . . . .
it maxed out the charger @ 15A until it got too hot and shut down to trickle charge . . . . !
so i added a second 15A NoCo G15000 charger, again same thing - maxed out @ 15A
i had the power monitor and the BMS was reporting a full 30A charge current going in . . . . thats all i had to hand.
The Valence U27-12XP will take a charge upto 70A !!! the these Lithium battery's are almost like a dead short on the chargers and will suck in all they can get.
the plan is to fit a Redarc BCDC1250D from @travelvolts when they arrive, which has a 50A charge capacity. (runing on the OEM 80/100A original SCR cables)
This is what we had after a few charging sessions.
all green with no faults showing.
SOC is reported @ 100% and didnt drop over night.
I've kept the charger connected and above 98% the charge current starts to reduce . . .15/12/10/8/6/5/4/2/1A . . all the way down to 0.1A
It looks like the internal BMS is now trying to "top balance" the cells around 3.4v-3.6v
one thing to note is that the battery spec calls for 14.6v for the top charge . . . .
but both chargers have 14.2v as there set Lithium program? (the Redarc shows 14.5v)
****************************************************
valence xp U27-12xp
battery specs.
Bulk 14.6v (3.65V PER CELL)
Absob 14.6v (3.65V PER CELL)
Float 13.8v (min 3.45v per cell)
C-rate. c/2 70A
*********************************************
charger specs:
Victron charge:
Li-on mode
Bulk 14.2v/15A
Absorb 14.2v/15A
Float 13.5v
******************
Noco charge
Bulk 14.2v / 15A
Absorb 14.2v / 15A
float
*************************
Redarc dc-dc charge. (bcdc1250d)
Bulk 14.5v / 50A
Absorb 14.5v / 50A
Float 13.6v
***********************
heres some pics showing battery now full at 14.1 and the two chargers i used.
*****
any questions?
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Wonder if a manufacturer will launch a battery with a BMS specifically for the leisure market (campers, boats, man sheds). With built in low temp protect. Surely if they go to the bother of an inbuilt BMS then adding this feature shouldn't be too much of an issue. It would also be interesting to see at what price the tipping point would be whereby the majority of folk would choose to pay for lithium as opposed to AGM in this market. I feel a T6F market research poll coming on.
im not sure any would, as its limiting the batteries operational limits . . . . . if they were advertising the fact. "our battery cuts out when its cold!"
it would make more sense for them to add in the internal heater and use that as a sales pitch . . . . like Relion and Epsilon. (our battery works in any climate)
The thing is Lithium batterys are a global market . . . . . and most places just dont get cold enough for this to even be an issue.
unless like us, you live in a temperate climate or somewhere else that is cold all the time . . . . . . so it makes sense that the manufactures make the batteries cheaper by omitting the LTD function.
but for us or people that live in a colder climate we need to look at a battery with internal heater . . . . or just add a 3rd party work around.
Thing is what Relion and Epsilon are not disclosing or telling us is how much power is being used/lost in keeping the battery at a happy temp..... im sure that at -10degC the battery will be consuming a fair amount of ah just keeping it warm.
We are effectively at the start of the Lifpo4 change over and it seems to be a rapidly evolving market with new features and changes being announced all the time....
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have you ever wondered how a Noco Lifepo4 jump pack works in cold temps . . . . . . . . . ?
look at this >
Look at the large Balast resistors that are stuck to the Lithium pack pouch . . . . . . . when its cold the jumppack bleeds its own power via these resistors to generate heat. thermostaticallc controlled of course..
so the question is if its very cold . . . . how much energy is used on self heating and how long can the battery last, static before is consumes all its own power?
........ NOCO GB1500 with a failed Lithium pack due to overheating (left in a very hot tent all day in summer!)
with all the testing and research I've done so far I've come to these conclusions. . . . . . .
- every Lifepo4 battery needs a LBD if you want it to last for the 4000 plus cycles its rated for if you are likely to discharge it low (basically any leisure battery situation where the possible chance if it running low is likely (fridge,lights,inverter,etc etc)
- if you have the cash then buy more expensive battery that has internal heaters for those winter months. (but a LBD is still recommended for a long life)
- if you dont have the cash, get a cheaper battery and look at the 3rd party solutions above for LTD, or just dont use them when cold (switch off charger with an isolator switch).?
- every Lifepo4 battery needs a LBD if you want it to last for the 4000 plus cycles its rated for if you are likely to discharge it low (basically any leisure battery situation where the possible chance if it running low is likely (fridge,lights,inverter,etc etc)
- if you have the cash then buy more expensive battery that has internal heaters for those winter months. (but a LBD is still recommended for a long life)
- if you dont have the cash, get a cheaper battery and look at the 3rd party solutions above for LTD, or just dont use them when cold (switch off charger with an isolator switch).?
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