LiFePO4 drop in's are they really a drop in?
I figured this might be interesting to those interested in drop-in replacement LIFEPO4 or the standalone cells themselves., based on the article below does not appear that is truly the case. Its a ...
Forum Discussion
Not sure if you're just chumming the water but here is a round about answer from just a few manufacturers for their dropins.
I believe the difference from one manufacturer to the next is their bms/ cell balancing requirements with in the pack.
Most suggest 0.5c charge/ discharge rate.
But like most things the end user should do their own homework to make a sound decision. What works for one might not work for the next. Personally I like the prismatic cells.
LiFeBlue Battery (LFP or LiFePO4)
http://www.lifebluebattery.com/rv-boat-lithium-ion-batteries/300ah-lithium-battery.html
The ideal charger has 3 programmable settings: Absorb voltage, Float voltage and Absorb time. Set the charger to Absorb at 14.2 ~ 14.6 volts, Absorb Time for 5 to 30 minutes, then 13.6 ~ 13.8 volts for Float. Some inverter/chargers have custom settings, some don't. Using the GEL battery setting will work. Some converters made for lead acid batteries will partially work but may let the battery discharge due to a low Float setting. Always disable or remove temperature sensors.
Battleborn battery (LFP or LiFePO4)
Posted by Sean (owner) from Battle Born Batteries. 3/9/17 post #31
http://www.airforums.com/forums/f449/battle-born-lifepo4-batteries-162132-3.html
Li-ion should not be floated. However, after they are charged they very slowly relax down to 13.6V over many hours. Therefore, by setting the float to 13.6V or lower, the charger is not actually doing anything because the pack will be at a higher voltage than the float. 13.8V is a little high for float and in the long run may degrade capacity.
In terms of charging, the pack will charge if you apply a voltage between 13.6V and 14.6V. But since voltage is the "driving force" for pushing current into the battery, it will take much longer to charge at low voltages. We recommend a charging voltage of at least 14.2V for reducing charge times. Also, 14.4-14.6 is optimal for allowing the cells to balance during the charge cycle.
Smart Battery (LFP or LiFePO4)
https://www.lithiumion-batteries.com/lithiumFAQ.php
"...charged as close to 14.4v - 14.6v as possible to get a full charge."
Our internal battery protection system is a high-tech innovative design made to protect the lithium cells. Features Include:
Internal Features:
-Low Voltage Protection Switch -Automatically disconnects at 8V.
-Over Voltage Protection Switch -Automatically disconnects at 15.8V.
-Short Circuit Protection Switch - Automatically disconnects.
-Reverse Polarity Protection Switch - Automatically disconnects.
-Internal cell balancing _ Automatically balances cells.
-Charge Balancing - Independant balancing for multiple batteries connected in parallel or in series.
RELiON batteries (LFP or LiFePO4)
https://relionbattery.com/resource-center/documentation
Charging Parameters 14.2-14.6
(From their downloadable charging pdf)
Charging with Lead-Acid Battery Chargers
Most lead-acid battery chargers can be used with LiFePO4 batteries as long as they are within the appropriate voltage guidelines.
AGM and Gel algorithms typically fall within the LiFePO4 voltage requirements. The voltage for flooded battery charging algorithms are often higher than LiFePO4 requirements, which will result in the BMS disconnecting the battery at the end of the charge cycle and possibly result in the charger displaying an error code. If this happens, it is generally a good practice to replace your charger for one with a LiFePO4 charge profile. Since the BMS protects the battery, using lead-acid chargers will typically not damage the battery.
...LiFePO4 can be charged with either a 1-stage profile (constant current (CC) aka Bulk Stage) or a 2-stage profile (constant current, constant voltage (CC-CV) profile aka Bulk and Absorption Stages). The 1-stage profile will charge the battery ~95% and the 2-stage profile will charge the battery 100%. The 1-stage profile is sufficient, since LiFePO4 batteries do not need to be fully charged; this will not reduce life as it does with lead-acid.
MASTERVOLT (LiFeYPO4)
https://www.mastervolt.com/products/li-ion/
(From downloadable user manual)
Bulk / absorption voltage setting 14.6 V
Float voltage setting 13.5 V
Victron battery (LFP or LiFePO4)
(From downloadable user manual)
Charge voltage Between 14V and 14.4V (14.2V recommended) Float voltage 13.5V
Just a little misc. info gathered. ;)
I believe the difference from one manufacturer to the next is their bms/ cell balancing requirements with in the pack.
Most suggest 0.5c charge/ discharge rate.
But like most things the end user should do their own homework to make a sound decision. What works for one might not work for the next. Personally I like the prismatic cells.
LiFeBlue Battery (LFP or LiFePO4)
http://www.lifebluebattery.com/rv-boat-lithium-ion-batteries/300ah-lithium-battery.html
The ideal charger has 3 programmable settings: Absorb voltage, Float voltage and Absorb time. Set the charger to Absorb at 14.2 ~ 14.6 volts, Absorb Time for 5 to 30 minutes, then 13.6 ~ 13.8 volts for Float. Some inverter/chargers have custom settings, some don't. Using the GEL battery setting will work. Some converters made for lead acid batteries will partially work but may let the battery discharge due to a low Float setting. Always disable or remove temperature sensors.
Battleborn battery (LFP or LiFePO4)
Posted by Sean (owner) from Battle Born Batteries. 3/9/17 post #31
http://www.airforums.com/forums/f449/battle-born-lifepo4-batteries-162132-3.html
Li-ion should not be floated. However, after they are charged they very slowly relax down to 13.6V over many hours. Therefore, by setting the float to 13.6V or lower, the charger is not actually doing anything because the pack will be at a higher voltage than the float. 13.8V is a little high for float and in the long run may degrade capacity.
In terms of charging, the pack will charge if you apply a voltage between 13.6V and 14.6V. But since voltage is the "driving force" for pushing current into the battery, it will take much longer to charge at low voltages. We recommend a charging voltage of at least 14.2V for reducing charge times. Also, 14.4-14.6 is optimal for allowing the cells to balance during the charge cycle.
Smart Battery (LFP or LiFePO4)
https://www.lithiumion-batteries.com/lithiumFAQ.php
"...charged as close to 14.4v - 14.6v as possible to get a full charge."
Our internal battery protection system is a high-tech innovative design made to protect the lithium cells. Features Include:
Internal Features:
-Low Voltage Protection Switch -Automatically disconnects at 8V.
-Over Voltage Protection Switch -Automatically disconnects at 15.8V.
-Short Circuit Protection Switch - Automatically disconnects.
-Reverse Polarity Protection Switch - Automatically disconnects.
-Internal cell balancing _ Automatically balances cells.
-Charge Balancing - Independant balancing for multiple batteries connected in parallel or in series.
RELiON batteries (LFP or LiFePO4)
https://relionbattery.com/resource-center/documentation
Charging Parameters 14.2-14.6
(From their downloadable charging pdf)
Charging with Lead-Acid Battery Chargers
Most lead-acid battery chargers can be used with LiFePO4 batteries as long as they are within the appropriate voltage guidelines.
AGM and Gel algorithms typically fall within the LiFePO4 voltage requirements. The voltage for flooded battery charging algorithms are often higher than LiFePO4 requirements, which will result in the BMS disconnecting the battery at the end of the charge cycle and possibly result in the charger displaying an error code. If this happens, it is generally a good practice to replace your charger for one with a LiFePO4 charge profile. Since the BMS protects the battery, using lead-acid chargers will typically not damage the battery.
...LiFePO4 can be charged with either a 1-stage profile (constant current (CC) aka Bulk Stage) or a 2-stage profile (constant current, constant voltage (CC-CV) profile aka Bulk and Absorption Stages). The 1-stage profile will charge the battery ~95% and the 2-stage profile will charge the battery 100%. The 1-stage profile is sufficient, since LiFePO4 batteries do not need to be fully charged; this will not reduce life as it does with lead-acid.
MASTERVOLT (LiFeYPO4)
https://www.mastervolt.com/products/li-ion/
(From downloadable user manual)
Bulk / absorption voltage setting 14.6 V
Float voltage setting 13.5 V
Victron battery (LFP or LiFePO4)
(From downloadable user manual)
Charge voltage Between 14V and 14.4V (14.2V recommended) Float voltage 13.5V
Just a little misc. info gathered. ;)
