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  1. Solarfun4jim

    Earth Rod attached to motorhome...any unforseen detrimental effects?

    In a rubber tyre insulated motorhome, is there any downside to attaching an earth rod to the chassis when parked up, when using 240v ac inverter power only(no grid tie or grid earthing) ? Is it safer with the earth rod connection or not?
  2. Solarfun4jim

    RCD question on a motorhome setting

    In a motorhome setting with the vehicle insulated from 'true earth' by rubber tyres, does the RCD in a 240vac distrubution board still trip if either the live or neutral cables make contact with the van metal, when there is no true earth, only grounded to the vehicle chassis? On developing the...
  3. Solarfun4jim

    Jim's RV build electrics

    Some of my setup modifications i have made are: Placed a layer of compressible insulation between the battery cell faces. Installed 6mm to 10mm aluminium flanged studs on cell terminals. (All connections torqued to 4Nm) Installed flexible braided busbars across cell terminals and from cell pack...
  4. Solarfun4jim

    Eve 280's expansion per cell?

    My reading of xuba's supplied datasheet on the EVE 280 cells, suggests a difference in thickness of 0.5mm between 100% SOC and 30% SOC. The cells themselves can vary +/- 1mm also, irregardless of SOC. @cinergi @HaldorEE Can either of you folks give me your 'average' cell expansion(ie per cell)...
  5. Solarfun4jim

    Starter battery questions

    In my (RV) VW Crafter handbook, the recommended battery appears to be 12v 70AH 340A SLA Installed currently is a 90AH 750A battery, which has obviously been installed by previous owner. (Functions fine) I know zero about batteries, but presume there are no issues(alternator etc?), when i go to...
  6. Solarfun4jim

    Annoying multiplus configuration setting

    Looking to run my 24V lifepo4 pack at conservative SOC limits. This means setting my low voltage DC input cut off at 25V(3.125v/cell). The only problem with this is, there is an automatic default minimum DC input reset voltage of 2v, thus the unit wont reset for delivering power again till it...
  7. Solarfun4jim

    Anything wrong with these multiplus settings?

    Looking at the settings above, do i need to change the absorption times at all? It is just that i was expecting, when charging from a low state of charge, that i would see bulk first, then absorption for 1 hour and then float mode, but what i'm witnessing is it going straight to float mode...
  8. Solarfun4jim

    Need help with multiplus 24/3000/70 inv/chg

    Having problems trying to get the Victron connect program to find my 24/3000/70 unit. Drivers installed. Connect software installed. UTP cable tried in both ports of multi. Have the MK3-USB connector connected up, with UTP cable going to UTP port on multi. Tried scanning on the victron connect...
  9. Solarfun4jim

    Are 'balancers' even necessary?

    In a Lifepo4 battery pack system, whereby charging would be 0.1CA, discharging would be 0.4CA(10% of time)& 0.1CA (90%of time), running from 3.1V/cell to 3.4v/cell capacity wise....any reason to consider any balancing measures whatsoever? If pack is top balanced initially and then never taken...
  10. Solarfun4jim

    A+++ fridge in a RV?

    Im looking at a standard home A+++ fridge (of 147 litres capacity) for use in my coach to camper van conversion. The annual power consumption is 62kWh/annum Would'nt appear to be a big draw on my 3000W inverter. It would only be getting used during summer months....so no unheated room use. Is a...
  11. Solarfun4jim

    Trickle charging starter battery in RV

    My RV (under conversion) from a minibus has a parasitic drain from a tachograph which is now obsolete from purpose, but cannot easily be removed because it generates the speed signal/odometer reading etc. I'm noticing that within a week of not driving, the starter battery gets to the point it...
  12. Solarfun4jim

    Busbar current carrying capacity

    I've noted a rule of thumb for Copper busbar current carrying capacity of 1.2*busbar width*busbar thickness in Amps. (What is Busbar Current Carrying Capacity Calculation 5 Types of Busbar | Electrical4u) The supplied Xuba busbars with my 280Ah cells were 15mm x 2mm, so applying formula means...
  13. Solarfun4jim

    Experimental question on charging

    If you had two identical setups, using the same pv panel input and same SCC's, but you set one up to charge at 3.65v/cell and the other to charge at 3.4v/cell, but both had their charges terminated by a BMS exactly when their respective first cell hit of 3.4v, what would be the expected...
  14. Solarfun4jim

    Still struggling to fully understand top balancing with bench top power supply

    @Will Prowse @FilterGuy @snoobler Looking at the operation of these bench top power supplys, you can either use as a regulator source or a steady flow source. In the regulator mode, you adjust the current knob clockwise to maximum, adjust voltage to the value required then connect the load. In...
  15. Solarfun4jim

    Capacity test results...is close enough good enough?

    Ran my first ever capacity test on my xuba 8S 280Ah pack at 0.02C discharge rate and after over 46 hours i achieved 275.4Ah (98.4%) I had a stubborn high cell and a run away low cell within the 8 cells. All cells were very well behaved up to approx 93% discharged capacity with the maximum cell...
  16. Solarfun4jim

    Using Chargery BMS without disconnect relay

    Im soon to be doing a 'capacity test' on my 8s battery bank. I wish to use my chargery BMS8T to monitor the cells but i do not have a dc relay for discharge cut off. I assume if i take the positive and negative wires from the discharge relay and simply connect them across a terminal block, then...
  17. Solarfun4jim

    question regarding digital multimeter

    Just started my first ever top balance of a battery bank...nerves jangling a bit....lol (8x280ah in parallel) Is there any harm in leaving a digital multimeter connected across the pack for hours at a time? Also, i noticed that after having set my bench top power supply to 3.63v it has crept up...
  18. Solarfun4jim

    Question regarding oversized SCC

    On a victron smart solar SCC, which is rated 150/45, purchased deliberately oversized for requirements so that i might add more array power later, do i need to reset the current closer to what my array can produce just now (30A) in the software settings or will the MPPT function handle it...
  19. Solarfun4jim

    Evaluating a charging/balancing strategy?

    On a mobile RV setup, with three charging sources, 1. Solar input via a SCC (constant whilst the sun shines) [0.1C charge rate] 2. A sterling Bat to Bat charger (to charge from vehicle on long drives). [0.2C charge rate]. 3. Charger on a multiplus inv/charger, whose charge function would...
  20. Solarfun4jim

    Any issues using a larger than necessary mppt SCC?

    It is my intention to purchase a SCC which is larger than needed for my current panel wattage, with the view i might add another panel later to the string. Current panel wattage is 740W on a 24v system. Was looking at purchasing a 150/45 Mppt SCC. (i really should only need a 100/30) Any issues...
  21. Solarfun4jim

    Another Top Balancing question?

    If top balancing an 8 cell x 280AH pack in parallel with a bench top power supply(10A output), setting the voltage to 3.6v and knowing it will take several weeks to charge the pack to that point(im in no hurry), what harm can be done to the cells if the pack is left for 24hours, still connected...
  22. Solarfun4jim

    BMS question regarding Chargery shunt

    Is the shunt on the Chargery BMS system used solely for calculating the battery SOC? Can the chargery unit be run without the shunt connected, with only the balance cables connected and still have all the necessary protections? If i installed a victron bmv712 plus shunt into my system, would i...
  23. Solarfun4jim

    Is this normal condition for a 'new' multiplus 24/3000/70-16 inverter?

    @Justin Laureltec HELP... Having just purchased a 'new' Victron multiplus inverter, i immediately noticed on opening it up that there is a scorch(arc) mark on a positive battery terminal plus it appears to have already been mounted to a fixture, going by the screw mark on the casing. Is...
  24. Solarfun4jim

    Checking my understanding using remote on/off function?

    On victron inv/chargers & SCC's with the in built 'remote on/off function', am i correct in thinking that i can simply run the live(+ve) output cable (only) from the charge & discharge control relays directly(from a chargery BMS). If my understanding is correct, a chargery BMS will out put 12v...
  25. Solarfun4jim

    Is my set up safe?

    Anyone care to comment on my proposed set up. Unsure about fuse sizing. Over sizing my SCC deliberately, but assume that has not significant detrimental effect on energy harvested? Would 600A 'welding cable be ok to use between the battery and inverter if kept less than 1 metre length? Thanks.
  26. Solarfun4jim

    Electronics questions

    Totally different world to me...so just picking up info at present.... 1/ If looking to use mosfets to switch loads up to 64V64A (>4Kw) , would good practice dictate using a single power mosfet with large heatsink or paralleling several fets to achieve the parameters needed? 2/ Any...
  27. Solarfun4jim

    Anyone with the right equipment up for some experimental testing?

    @Will Prowse Any of the 'Tech heads' on here, that have the right equipment, up for running some experimental testing on a single lifepo4 cell? A range of experiments plotted on a graph could be very illuminating(with regards specifically to solar charging and low C rates). Keeping in mind...
  28. Solarfun4jim

    RV schematics/diagram specfic to UK code

    Hi folks, i'm looking specifically to UK van/motorhome dwellers to provide a schematic or rough diagram of their layout, with specific reference to meeting UK code on grounding/earthing, chassis ground etc. Some appear to have no 'units' bonded to chassis, only the negative busbar. It all seems...
  29. Solarfun4jim

    Question on SCC disconnect comparison

    In the setup's below, which would function best for longevity or which would be a strict no-no for reasons given. (Just experimenting with idea's at present)
  30. Solarfun4jim

    Trying to get my head round solar input values?

    Looking at the comparison graphic below, i've heard several times that charging at a lower voltage threshold will take much longer to charge a battery bank. Can someone explain how this comes about, since the same 'overall wattage' is being input. Edit...cells would be 280Ah and 1C charge =...
  31. Solarfun4jim

    SCC and inverter/charger charging at different voltages....any issues?

    In a scenario, where a SCC is set to charge at say 3.6v/cell and an inverter/charger set to charge at 3.5v/cell, would there be any issues with the different voltage settings when both charging at the same time? I'm assuming not, but always better to get confirmation. :)
  32. Solarfun4jim

    Victron remote switches...what is needed

    @Justin Laureltec On Victron SCC's & Multi Inverters which have the 'remote' on/off switch, can a 12v 0.8A output from a 'non victron BMS' relay be sufficient to operate these switches directly? If not, what hardware needs to be connected to make this functional? Relay is 'always powered on'...
  33. Solarfun4jim

    Solar Panel Array query?

    If a solar panel array is 'powered up' in full sun but not connected to any load, are they damaged in any way? Is the energy generated, dissappated through a diode or such, or does no energy actually flow, unless connected to a load. Just trying to understand how they function.
  34. Solarfun4jim

    Grounding/earthing question on a RV

    When using an 'All in one' unit, when plugged into grid power, then i understand that the earthing is through the connecting cable. When no grid power connected, on the vehicle, where the engine battery is 12v negative earth, how is the earthing handled when the 'all-in-one' unit is connected to...
  35. Solarfun4jim

    Throwing an idea up in the air....critique welcomed?

    If building a large battery pack for a RV, if leaving adequate space between the cells, for heat dissapation, but still wishing rigidity for Aluminium walled cells, how about filling the voids between the cells with kiln dried sand? This would pack down over time with all the movement, so could...
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