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  1. mikefitz

    Pre-Absorption for Lithium-Ion

    No, can you identify which batteries need this? I guess it's a limited low current stage at absorbtion volts.
  2. mikefitz

    Troubleshooting 30 amp solar controller barely charging battery

    The DC input on the powerstation is used for DC power or solar panel, 11 to 28 volts, 120 watts, 10 amps. Connect your panel directly not via a external controller. The unit has an internal controller that accepts panel directly.
  3. mikefitz

    Over voltage warning

    There is a tollerence on the panel specification, your new panels are generating a higher Voc. From the Epever manual for the 60A 150 volt unit,
  4. mikefitz

    Please review my off grid solar diagram

    Eight 108Ah batteries in parallel idealy need a higher charging current than the maximum of 20 A via the PWM controller. The generator at 60 amps is better and may be needed to bring the batteries to full absorbtion state. There could be issues with the batteries not being fully charged thus...
  5. mikefitz

    RV Question about solar panels, controllers, and batteries

    This may happen with low cost PWM controllers like the unit provided with your kit. More advanced controllers are usually protected against panel disconnect. In fact the Victron range of controllers happily operate without battery connection. ( once initially powered with a battery to...
  6. mikefitz

    Epever 3210AN power off during night

    Usually AGM needs a higher charge voltage than GEL , default for the 3210 on the GEL setting is 14.2 boost volts. Either change to USER and set a 14.6 boost volts or change back to sealed settings. Check load output is switched on, manual page 19,20. Possible faulty interconnection...
  7. mikefitz

    fuse help

    If a single battery charging limit is 10 amps, then with a series setup it's still 10 amps, that's the current through each battery. 10 amps seems low for a 100Ah battery, is this the BMS limit, or a recomendation? Charging voltage may be too high for new batteries, suggest 56.8 or 56.0 if...
  8. mikefitz

    Do I need diodes in this battery design?

    Use a battery charger connected to the battery. The Meanwell type of power supply do not have an ideal current limit, they fold back or burn out if overloaded. Connecting to the MPPT input via a diode, (only needed in the positive path of each source), may work, ( use a 35A bridge rectifier...
  9. mikefitz

    Do I need an Active balancer for two 12.8v 100ah in series?

    https://www.ebay.com/itm/175874775173 https://www.ebay.com/itm/235361478930 Over time the batteries may/will become out of balance with each other leading to charging or power delivery issues. Since you will be using a 24 volt charger it's possible the weaker battery will hit cell overvolts...
  10. mikefitz

    New accumulators for the electric wheelchair

    Not serious but may prevent the battery pair from reaching the same state of charge. What is happening is that, under charge, one cell is reaching protection voltage limit and preventing further charging. The battery will still function under load. This is common with new batteries and it...
  11. mikefitz

    New accumulators for the electric wheelchair

    Hi, as sugested your batteries are overheating during discharge. There appears to be only one temperature reported by the BMS and this is the temperature of the battery cells or the temperature of the internal battery control electrics. It may be under high power requirements, the control...
  12. mikefitz

    Trickle Charging LifePo's

    The controller should charge to a target voltage, boost volts, ( absorbtion voltage), then after a period at constant voltage drop to float volts. The concern discussed in the video is that the controller does not drop to the lower float, but continuously charges at the higher boost volts. This...
  13. mikefitz

    AiLi battery meter accuracy issues

    No, the monitor does not need to know battery type, it just measures volts and amps, does some sums and estimates SOC. Both the Aili and the BMS will have errors, especially if low currents are involved.
  14. mikefitz

    How would you set the charging parameters for LiFePO4 DC-DC charger?

    No, I was discussing the boost duration, this is the absorbtion period where charge voltage is constant at boost 'target' volts. With a low charge current and a large battery this time duration can be zero or a short time, say 30 minutes. Some SRNE solar chargers get confused if the boost...
  15. mikefitz

    Can't reset BMS

    The battery is in protection mode. Try, Disconnect from the charger and apply a DC load greater than 2 amps. Else, Connect to a 12v source , car battery or power supply. ( not a charger, many chargers will not function unless they 'see' a voltage from the battery). There are 4 options in the...
  16. mikefitz

    How would you set the charging parameters for LiFePO4 DC-DC charger?

    The charge voltage with battery loading is no different from charging off load, the current into the battery is just less than with no load. With a 50 amp charger and load of 15 amps, that's 35 amps into 560 Ah battery. With this very low charge rate by the time the charger hits 'target' boost...
  17. mikefitz

    BMV712/Battery Protect with thermal sensor (BMS - no low temp)

    The Victron battery protect is a one way device, cannot have both loads and chargers on the input. Also no inverter loads are allowed on the protect output. The Smart Solar can disable charging based on the information from the BMV temperatures sensor. The Victron stuff talks each other, VE...
  18. mikefitz

    I'm tired of unreliable 'all in one' systems to power my fridge!

    Agreed it does not indicate the SOC, but it records the duration of charge, absorbtion and float for the day. With the low charge currents of the proposed system, by the time the battery reaches absorbtion volts, 14.2 default value, and drops to float, you can be quite confident the...
  19. mikefitz

    Does anybody here think 12 volt is the way to go for flexibility?

    Connecting 12v batteries in series, each with its own BMS, to create a higher voltage battery will eventually have balance issues. You can add battery ballancer hardware to help solve the issues, but its good engineering practice to have a 16 cell 48 volt battery with a single BMS .
  20. mikefitz

    Did I damage (4) Battleborn batteries?

    There have been reported issues with the terminals on Battleborn batteries becoming disconnected internally.
  21. mikefitz

    Possible Voltage Spikes from Victron Orion DC-DC Frying My Truck Electronics?

    This is unlikely. The most probable is the alternator or the control electrics for the alternator, being faulty. ( some alternators are under control of the engine ecu). Many vehicles have battery current monitoring in the path between battery ternimal negative and frame/vehicle metal...
  22. mikefitz

    Circuit breaker fail.

    Poor quality low cost breaker, replace with Bussmann/Blue sea, Example, https://www.ebay.com/itm/395209237520
  23. mikefitz

    Problems with renogy bluetooth bms

    Renogy batteries seem to cause problems for many users, a search on this forum will bring up many issues. It's possible the battery is in protection mode. 10.8 volts and 78 % SOC cannot both be true. A protection short should self recover unless the BMS is damaged during the short...
  24. mikefitz

    100% SOC, absorption/float for constant loads

    Seems a satisfactory situation. 13.5 volts is slightly above resting voltage so the battery will remain 100% stare of charge whilst also powering loads. 14.2 volts absorbtion even with a short absorbtion period should reach full charge.
  25. mikefitz

    Sometimes works, sometimes doesn't

    If your system has 230v AC appliances/ lights and includes a inverter in 'eco' mode, then it's in standby until it 'sees ' something consuming power. The setting in the inverter for detection of power use may be adjustable. More details of the equipment installed would be useful. Mike
  26. mikefitz

    Using boost converter for charging LiFePO4 from starter battery/alternator

    Yes it lasted 15 seconds. Recomend a 'real' charger, Victron Tr Smart, https://www.ebay.de/itm/134004769323
  27. mikefitz

    Renogy 50A Dual Input MPPT ongoing charging problem

    It would be useful the know the charge state of the battery and the voltage of the battery before charging starts. It seems unlikely 3 units would fail, so unless there are connection issues, ( low cost breakers can cause problems), the battery may have developed unbalanced cells that's...
  28. mikefitz

    Help, Dc to dc charger Input fried?

    Some early Orion Tr Smart were running very hot. Victron made a manufacturing change to reduce power with increasing internal temperature. The early units will be replaced FOC. This link discussed the issue, pic is serial numbers of effected units...
  29. mikefitz

    PWM fuse size help

    The fuse in the controller feed to the battery is to prevent excess battery energy causing damage/fire to the cable and controller, if a cable or controller fault occurs. The 400 watt solar via a PWM is 20 amps max into 12v system. Fuse 25 or 30 amps at the battery end of the cable , awg8...
  30. mikefitz

    Help, Dc to dc charger Input fried?

    Overheating terminal, perhaps poor quality cable or loose clamp. 8 awg is indersized but the drop on a 1.5M run is not excessive. Any reduction of input volts is going to increase input current as the unit needs 400 watts input to supply the charge power of 360 watts. When testing for volt...
  31. mikefitz

    Help, Dc to dc charger Input fried?

    The Orion tr start or Orion XS is for vehicle DC to DC charging, has programmable charge profile via Bluetooth, and has settings for voltage input level a activation/deactivation, ( thus knows when the alternator is charging). The Orion DC to DC converter, ( as Orion, OrionTR, or Orion IP...
  32. mikefitz

    Battery remains at Bulk Charge Voltage

    Read the previous posts the OP made, https://diysolarforum.com/threads/upgrade-solar-wire-guage-for-better.79616/
  33. mikefitz

    Battery remains at Bulk Charge Voltage

    With 800 watts of solar, a 12 to 15 amp load, and a 145Ah battery it's possible the battery has been damaged. Discharging fully to 11.6 volts will, reduce battery life, as will excessive charge current. Even though the battery self limits to some degree, if its in a low state of charge it...
  34. mikefitz

    Hi everyone. Can i have any advise in buying secondhand Renogy 170ah, which can only be charged up to 90ah, LiFePo4 batteries, please?

    Read , https://diysolarforum.com/threads/problems-with-renogy-170ah-batteries.74567/ The battery you are considering may not have lost capacity but because of cell inbalance cannot charge correctly.
  35. mikefitz

    Noobing myself on series/parallel tradeoffs

    Parallel conection of panels does not need matching current, however the shaded group will have a different maximum power point that may reduce the MPPT performance where a single controller is used. Ideally seperate controller for each group would give best performance. It's unlikely you...
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