January 29, 20233 yr Not wanting to shell out money for expensive Victron or Optimate 12v life charger, is there any alternative that is more affordable? Looking for something that can charge a 12v Lifepo Battery at 8 to 15 amps...any ideas? Maybe ideas to build one myself?
January 29, 20233 yr 42 minutes ago, Chris_H said: Not wanting to shell out money for expensive Victron or Optimate 12v life charger, is there any alternative that is more affordable? Looking for something that can charge a 12v Lifepo Battery at 8 to 15 amps...any ideas? Maybe ideas to build one myself? At a price of R300 the China power supply rated at 30A can charge up to about 85% SOC. The 20A is cheaper. Google on Takealot or Robofactory. Add XH M602 control module to any other charger that perhaps have an output up to 14.5V or a bit higher and set the controller to disconnect at the level you want around 14.2V. Controller about R130. Edited January 29, 20233 yr by Scorp007
January 29, 20233 yr 1 hour ago, Scorp007 said: At a price of R300 the China power supply rated at 30A can charge up to about 85% SOC. The 20A is cheaper. Google on Takealot or Robofactory. Add XH M602 control module to any other charger that perhaps have an output up to 14.5V or a bit higher and set the controller to disconnect at the level you want around 14.2V. Controller about R130. Just in case you don't know, that controller simply switches the input to battery on and off based on the voltage set, it does not control current at all.
January 29, 20233 yr 8 minutes ago, P1000 said: Just in case you don't know, that controller simply switches the input to battery on and off based on the voltage set, it does not control current at all. Yes that is correct. The final voltage will be lower as the battery voltage will be about 0.4V higher during charge and depending on the charge current. I have been using it for over a year on different battery types. To be 100% correct the controller actually switches the 220V AC off. Edited January 29, 20233 yr by Scorp007
January 29, 20233 yr Author 1 hour ago, Scorp007 said: At a price of R300 the China power supply rated at 30A can charge up to about 85% SOC. The 20A is cheaper. Google on Takealot or Robofactory. Add XH M602 control module to any other charger that perhaps have an output up to 14.5V or a bit higher and set the controller to disconnect at the level you want around 14.2V. Controller about R130. thx have looked at this but need 100% SOC charge ideally
January 29, 20233 yr 1 hour ago, Chris_H said: thx have looked at this but need 100% SOC charge ideally If it was from PV then the Epever MPPT that has every possible lithium setting could have been used. Below R1500.
January 29, 20233 yr The life4po battery you want to charge i assume have an BMS? or what brand is the battery? I think as Scorp007 suggested , any solar charge controller that you can set the bulk/absorption voltages should work. The voltage relay should also do the same job. Cheapest i would say a 18V-24V power supply connected to the mppt/pwm input of solar charge controller. Connect battery to output. Set the voltages or select the lithium option. Fine tune the voltages by measuring the amps drawn , when bms switches off the internal charging. to get close to 100 percent SOC. Or any comment why this wont work? my opinion taken the temp coefficient of life4po you actually do not want to charge the battery to full/100 percent to reduce the chance of over voltage or ddamaging the battery if the ambient temp rises, but this is my humble opinion. The amount risk of damaging the battery vs capacity you loose i would say charge battery to less than 100 percent and stop. https://www.power-sonic.com/blog/how-to-charge-lithium-iron-phosphate-lifepo4-batteries/ also , What are the proper charging voltages for the 12V, 24V, and 48V lithium batteries? Our Battle Born Battery charging parameters consist of the following: Bulk/absorb = 14.2V–14.6V. Float = 13.6V or lower. No equalization (or set it to 14.4V if possible). No temperature compensation. Absorption time is approximately 20 minutes per battery, if possible. For a 12V system, we really want to emphasize reaching 14.2V – 14.6V for bulk and absorption and float to be 13.6V or lower. For a 24V system, we suggest a bulk and absorption rate of 28.4V– 29.2V and float to 27.2V or lower. No equalization is required, but if it’s possible we suggest 28.8V. No temperature compensation is required either, and absorption time is approximately 20 minutes per battery if that is an option. For a 48V system, we recommend a bulk and absorption rate of 57.4V and floating it at 56.5V to 57V. Sometimes, one of the batteries may trigger a high voltage disconnect in your system. The battery’s internal BMS will help handle a high voltage disconnect. Our team wants to emphasize that, overall, there’s no harm in playing around with charge rates to optimize your system.
January 29, 20233 yr 5 hours ago, Chris_H said: Not wanting to shell out money for expensive Victron or Optimate 12v life charger, is there any alternative that is more affordable? Looking for something that can charge a 12v Lifepo Battery at 8 to 15 amps...any ideas? Maybe ideas to build one myself? The problem with lipo charging curcuits lie in the 10% and lower SOC whereas the current drawn is the highest due to the low internal resistance of the cells. I am busy testing SMPS 40 amp adjustable between 9.3v- 14.4v ideal voltage and it is a CC ps and around R300. The problem though it consist of a hiccup current limiting curcuit that does not work as the voltage drops to 0v on overcurrent. I am busy building a flyback current limmiting curcuit to limit the current between 10- 30amps( adjustable). There is very limited lipo chargers available in the lower price range in SA. I will keep you posted on my progress.
January 30, 20233 yr Author 14 hours ago, TaliaB said: The problem with lipo charging curcuits lie in the 10% and lower SOC whereas the current drawn is the highest due to the low internal resistance of the cells. I am busy testing SMPS 40 amp adjustable between 9.3v- 14.4v ideal voltage and it is a CC ps and around R300. The problem though it consist of a hiccup current limiting curcuit that does not work as the voltage drops to 0v on overcurrent. I am busy building a flyback current limmiting curcuit to limit the current between 10- 30amps( adjustable). There is very limited lipo chargers available in the lower price range in SA. I will keep you posted on my progress. thanks, I am also testing using a regular 10A solar controller with a 8.3amp 12v power supply (LED driver)
January 30, 20233 yr Author 14 hours ago, jlr said: The life4po battery you want to charge i assume have an BMS? or what brand is the battery? I think as Scorp007 suggested , any solar charge controller that you can set the bulk/absorption voltages should work. The voltage relay should also do the same job. Cheapest i would say a 18V-24V power supply connected to the mppt/pwm input of solar charge controller. Connect battery to output. Set the voltages or select the lithium option. Fine tune the voltages by measuring the amps drawn , when bms switches off the internal charging. to get close to 100 percent SOC. Or any comment why this wont work? my opinion taken the temp coefficient of life4po you actually do not want to charge the battery to full/100 percent to reduce the chance of over voltage or ddamaging the battery if the ambient temp rises, but this is my humble opinion. The amount risk of damaging the battery vs capacity you loose i would say charge battery to less than 100 percent and stop. https://www.power-sonic.com/blog/how-to-charge-lithium-iron-phosphate-lifepo4-batteries/ also , What are the proper charging voltages for the 12V, 24V, and 48V lithium batteries? Our Battle Born Battery charging parameters consist of the following: Bulk/absorb = 14.2V–14.6V. Float = 13.6V or lower. No equalization (or set it to 14.4V if possible). No temperature compensation. Absorption time is approximately 20 minutes per battery, if possible. For a 12V system, we really want to emphasize reaching 14.2V – 14.6V for bulk and absorption and float to be 13.6V or lower. For a 24V system, we suggest a bulk and absorption rate of 28.4V– 29.2V and float to 27.2V or lower. No equalization is required, but if it’s possible we suggest 28.8V. No temperature compensation is required either, and absorption time is approximately 20 minutes per battery if that is an option. For a 48V system, we recommend a bulk and absorption rate of 57.4V and floating it at 56.5V to 57V. Sometimes, one of the batteries may trigger a high voltage disconnect in your system. The battery’s internal BMS will help handle a high voltage disconnect. Our team wants to emphasize that, overall, there’s no harm in playing around with charge rates to optimize your system. thanks that is my plan will keep you guys posted
January 30, 20233 yr Author This is the charging characteristics of the solar charger I am considering using, should be OK to use it with standard values.
January 30, 20233 yr might be an idea to check the hobby shops. for the radio control guys there is a variety of lipo chargers available. My old car ones can charge from a 24v source at up to 15 amps. i use it for charging my gel cells, nimh rechargeables, 2s, 3s ,4s lithium packs etc.
January 30, 20233 yr 2 hours ago, Chris_H said: This is the charging characteristics of the solar charger I am considering using, should be OK to use it with standard values. Drop equalizing to 13.8v or disable if you can. Bring bulk down to 14 or 14.2v. What are you planning on using PWM controller or MPPT
January 30, 20233 yr Author 1 hour ago, TaliaB said: Drop equalizing to 13.8v or disable if you can. Bring bulk down to 14 or 14.2v. What are you planning on using PWM controller or MPPT Planning on using PWM.
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