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By experience, i often see sla battery died or capacity fade after long floating period (many month) without cycling just on ac charger at 13.3V. I don't know exactly why but I can't recommend using sla battery without cycling once a week.

offcourse but you will never cycle your sla battery without discharging a lot your lifepo4 battery and the goal is to use sla battery up to his end of life to remplace it by lifepo4 efficient battery. trickle charge is a loss for something you don't use everyday, non sense for me

there is absolutely no problem with mixing SLA and lifepo4 but you will need some smart logic to cycle both battery in their needs. You can setup bms to disconnect lifepo4 at 14V to charge SLA up to 14.4V For the discharge periode you can start to discharge first SLA battery to a 40-60% Soc then...

Why using spring in that case, constant pressure compression maybe? lol

plastic is not compressible, sikaflex is compressible allowing cell expansion

I try adding space between cell because if thermal wrap insulation on cell failed there is a short of 10000A @ 3.2V I chosen to make a litle grid of sikaflex 1mm thin to isolate from next cell and be able to compressing

You can use collector output for driving contactor from positive battery or emiter output for driving contactor from negative battery. Verify the max current capability of this output and your contactor current requirement. 28.3v is very high for floating mode. I never set more than 28V for...

Hi i would like to share a method to test and identify matched cells when a "big" order is coming. This time i received bulk 37cells from alibaba then i would like to pairing 4 cells by capacity and IR to paralleled setup like 4S3P. Testing cell can be very time consuming and energy consuming...

YR 1035+ is fine for our application and it's a low cost AC IR tester

high IR mean old used cell. As IR AC tester is doing fast discharge charge at 1khz for mesuring it's better doing this without external current. 0.2mOhm (280Ah) at 1C discharge = 2% heat loss, and as you can double IR AC for continous DC discharge, in reality it's 4% heat loss

good, test these cells vs your EVE cells, accuracy isn't very important

Peltier can be efficient with low voltage like 3.3V instead of 12V, i was thinking remplace dump balancing resistor by peltier module and activate balancing at 3.4V to keep them cold for charging

I would like to see a real AC IR mesurement, easy to say new harder to have a video of real mesurement

Check cell terminal connection and mesure voltage directly on cell

Teardown your welding machine, and mesure the voltage from electrolitic capacitor high voltage, then feed them with solar pannel array when your small inverter output AC current is near > 20% nominal! Switch off solar array when inverter outpout is < 10%. You have to deal with IGBT for...

i bought 16cell lishen from basen in 12/2020, all very good 0.13mOhm and no need to balance @ 3.5V avg per cell, no top balanced. no need to balance at 3V avg per cell (DV = 5mV). I have 4cell at home without bms since 7month, delta V is < 10mV! I hope receiving same quality from other seller...

Hi, i lookingfor some information to setup rec bms + gateway victron cerbo gx + victron skylla charger in smart way to slowdown charge or even stop charge when higher cell > 3.65V. On the gateway everything is link with VE.can or VE.bus (inverter phoenix), recbms is link with BMS.can and nothing...

Maybe it's just a boost topology at the input (pretty sure of topology) just for perturbing the voltage at the input, deactivate mosfet lowering solar voltage by 0.6V step easy without change duty cycle on buck module and see what's happen on mppt. I'm sure im seen pulse on gate on the mosfet so...

Yes it's the usual ideal diode with pwm design o_O Sorry i will don't explain again what i seen on my repaired mppt and what my digital scope showed at the screen. You simply can't make antenna with a dc current souce dipole

If you teardown (not easy) a bluesolar mppt 100/50 there is 6mosfets, two at the first stage as sync boost topology (wire is inductor here) and 4 mosfets (halfbridge) in dual buck topology with dual inductor. Using inductance of wire is good to avoir capacitors at solar input and solve the...

first thing first, you have to determine the real number of cell on your solar string and the probability that a portion is shaded by obstacle function of day time; here is the 7day history usage. There is no secret, look-for mppt take time and the less range you have to look-for faster response...

first thing i disagree victron mppt have a boost module to take advantage of inductance of solar long cable and are able to stepup voltage before step down

All mptt that range over "V range" are simply bad algorithm. The range can be learnt (local topology, daytime) and reduced to a minimal range for looking the best power point as fast as possible

Yes but at the cost of IR loss in cable, not a big deal in house and short ac cable. it's like you want drink 1liter of water with one plastic bottle and you don't finish the water inside to refill the source water tank then refill your water bottle to finish your 1liter drink. a bit inefficient...

I regret mppt like smart victron mppt can't setup a minimal voltage power point and learning from 7 past days what is the real range of mppt voltage. Same for maximal voltage power point, and maybe some larger trial once a week when output current is high in order to reveal some wiring loss or...

Put this battery in safe zone, it's can fire fast if damaged cell is paralleled. You can try to charge only the lowest cell with an AC 18650 charger (normaly there are isolated and no ground loop) and see

I often add ntc thermistor on cheap converter to add current regulation and keep working at good efficiency but the drawback is weak precision on voltage output setting; NTC 47kohms is parallel with FB divider high side resistor, when device is heating, the output voltage is going down and...

Yes it's very clear now, shaded cell see negative voltage and positive current and when we inject power cell voltage is positive, function of iradiance and current is negative.

In the link : For 24 cells, the “breaking point” voltage is about 336 volts" this is a lot of high voltage to feed a 76cell panel! edit : i just made a real test on small 150w panel voc = 20V, isc = 9A At 21V with the solar panel under sun i was able to inject > 1A (current limited mode) At...

Hi, for heating solar panel i suggest to see this video for the principe of physics I think you can supply a solar panel with the normal current flow with a negative supply (and current regulation to not damage cell) it's will emit infrared light perfect to heat. the main issue is bypass...

halogen 500W light is cheap but doing 25kw dump load when you even don't know the ac or dc is the same on resistive load, is not really a good idea! Be carefull 90VDC@280A make nice and dangerous electric arc (coper cables are inductive) even with resistive load

thank you for your feedback, so you can confirm the main contactor never open on canbus loss? I will install a recbms16s next week and your information is really appreciated, i will just add WS500 alternator controller on your setup! Because i have seen 20000$ damage (autopilot and every 24v...

Canbus transceiver in my car, canbus in the sailing boat on nmea2000 systems because lightening near from the boat.

if alternator are loading massive amp to the battery then there is a drama , this single point of faillure is crazy

Hi, did you know where we can find the canbus protocol detail for limiting current or change target voltage from these corporate charger? Only one day canbus will fail, and only god can know what's happens