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For example.... https://www.alibaba.com/product-detail/Walkable-thin-film-cigs-solar-panel_1600094266610.html SN-CIGS560W gives 560W at 1.3m wide and 2.6m long..... not sure what diameter you could roll it into, but for desert use, in a box would stop it getting dusty between usage. Dont know...

Looking at the spec on an 'All in one' unit, it states that maximum string voltage as 145V It also states that MPPT in operating range 30-115v If the open circuit voltage of my array string is 130v, what happens with the MPPT? Does it simply ignore the voltage from 115v up to 130v or does it...

Those cables are a bugger to bend....not so bad once they get warm :)

So, as regards grounding on an RV setup, with a multiplus inverter, where it can sometimes have a grid connection, which diagram below has the correct grounding configuration .... A, B or neither...please explain your conclusions(Grounding cables in green) A B

If it is set up to disconnect the whole bank, not simply one defective pack, then if any cell goes out of whack, you know immediately to go investigate. If you only loose one string/pack out of four, the urgency of the situation might not be quite so apparent.

You might care to look over this range of products below to see if there is anything suitable ... https://sterling-power.com/products/2015-battery-to-battery-chargers-non-waterproof-drip-proof-ip21

Cheers snoobler, thanks for the input. (y)

Perhaps about 20cm according to one of the images

I thought the cells had to be fairly close in voltage before you connect them in parallel or else there is too much inrush current? Just how close do they need to be? I can bleed off some wattage with a 30ohm resistor to get them closer before i connect them in parallel, just dont know how close...

yeah, that element i suggested wouldn't do. :-(

@FilterGuy Love that board. It would be absolutely perfect for my needs. I've never tried to do any electronics before, but this encourages me to have a go....so thanks for that. (y) Where did you get the pc boards made for that design...would you have a link?

I would have thought that by putting thread locker on the bottom of terminal hole, when you screw down into it the 'air pressure' plus thread locker mix would be forced up the threads(so long as you didnt put down too much)?

Thanks...will use your guidance. Easy enough to 'set it' at the battery terminals for accuracy.(when i eventually do this) Accept that 4v is very high, but that was part of the experiment, to see how much the higher differential could drive the rate of charge....i suspect the benefits tail off...

It is the single most important aspect to get 100% right first time, as just sometimes, you dont get a second chance to change your mind. Hence why i have been going on and on and on about it, boring numerous posters with it....lol.

Roll it out like an awning from back of truck? Simply another avenue to explore...good luck. (y)

Totally inexperienced...so forgive me if this idea is totally stupid.... If once the terminals have been cleaned (and busbars also) and you have established good contact at the surface interface, could you completely seal things up with some high temp silicone over the whole connection? That way...

I ordered my xuba cells with double busbars. My question is this, if you double up the busbars and add a BMS/balance lead, do you need to replace the supplied screws with slightly longer ones or will they still have enough threads in contact? I'm assuming you do not need to use a locking washer...

Snoobler....it is AC input not output(for clarity). I do not need 'charger only function', so a close/connection between the left terminal and middle terminal would suffice for me. I need the charge relay to shut down all charging when HVD (incoming grid power and SCC power) I need the...

I had thought that the first charge cycle was different from subsequent ongoing charging. Should you perhaps use 3.65v per cell on first charge and top balance the pack at that, then thereafter, charge up to anywhere between 3.4-3.6v per cell depending on the capacity & longevity preferences you...

@Steve_S Hi steve, any chance you happened to verify the accuracy of the low temp disconnect, once you had set it up? I remember Will having checked another 'make' and it proved to be rubbish. Just curious...i know how you love to tinker with these things :)

I'm surprised you decided the conductive silver epoxy was not worth it. What is your reasoning for this?

Ahhh....perfect Craig. Gotcha.

Thanks. Most of the 'All in one' units are similar in this respect, so not unique to this supplier. Just seemed a bit pointless, if it shuts down. If it ignores the 'extra' voltage above the 115V limit, might this give a degree of over panelling for cloudy weather conditions???

I would love it if you could attach some quality UK supply URLs to these items/relays/switchgear(as you will know far better what is good), ie like perhaps using these for the bypass switches...

I had thought that would only happen once the cell was approaching full, ie when it switches from CC to CV. Although some of the testing is proposed at 4v, the termination was set at 3.6v. It might well be, you only get the bulk charge portion and not the absob CV state before terminating at...

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...

@ghostwriter66 Your point 1 (for the benefit of newbies),with articles i've read, would indicate heat from 20degC to 30degC actually helps lifepo4 perform better(so not all heat is bad) Maybe they should relabel it as 'All heat above 85degF is bad'. Also if charging from a (solely) solarPV...

Thanks jason, 2S would be just over 80Voc. Might not have room on top of RV for 2S2P, but 3S would be doable. That would be under the 145V threshold, but above the 115 MPPT limit. Just trying to make sense of the spec on these units.

Thanks cal. Yes i knew it would get interesting if the disconnect closed down the BMS, but thought it might be better to protect the battery pack at all costs and rewire the relay for restart afterwards. Your inputs are greatly appreciated. (y) I have emailed Jason Wang to see if he has any...

Cheers steve, kindly keep us posted how you get on...especially if you see any improvements in cell voltage accuracy.

I only had threadlocker, not epoxy and i could only use the tiniest amount, because i couldnt afford for it to squish up to the terminal face, but it secured the flange stud so securely, that when i used 8Nm torque to try and free it again(because i had noticed a tiny gap between the stud flange...

Hi filterGuy, see rough drawing below....hope it is clear enough to give you an idea

Brilliant....love getting info based on actual experience. The bigger ones are advertised for golf buggies, rv's etc, so you would think that if they failed too often, it would become known. Thanks. (y)

Thinking out loud, if you had a trigger event, bypassed the defective pack and ran the good one down, repaired the defective pack, then seperately charge each pack back up to the same full soc voltage(seperately) before bringing them back into parallel again, would this help maintain the top...

The thing about RV battery banks, is that they are likely to be built in, under a bench etc. Getting access to them every 6-12 months to check on the balancing would be a PITA. Initially, i had thought that an active balancer would distribute up to 6A to each individual cell, all the way up and...

Yeah, understand...all about priorities. Space/weight premium.

It is a pity the supplied busbars are not slightly longer, that way you could connect the cells in either direction. The inside of the slots to connect the cells side by side and the outside of the slots to connect length ways! (Maybe a suggestion for AMY) ;)(y)

cheers Bob. (y)

Thanks Hedges, that clears that up for me. (y)

@astronom Thanks for that astronom, i was thinking of that totally differently. I had thought, in the 100A shunt, that each 75mV difference/drop would give 1333 points of reference and each one would equal 0.075A In the 600A shunt, each 75mV difference/drop would give a total of 8000 points of...

I looked at this idea a short time ago, trying to control the power switch on an 'All in one' unit, but the problem i ran into was controlling a 240vAC circuit switch with a 12v DC relay output. Didnt know enough about relays etc to feel confident. :-(

Thanks filterguy, much appreciated. Yes the max continuous load would be 100A with a 200A peak surge. Either bypass switch would only be closed after a triggered event, in which the BMS's would both be at off. Once the bypass on good pack was closed, simply activate the switch on the delay relay...

I especially like the thinking on this, in relation to RV's where having a few days autonomous capacity, means that the bank might rarely be drained below say 65% soc and then 'topped up'. It is more likely to be parked up in the Sun topping batteries towards full while the occupants enjoy...

@Steve_S I've noted with several BM shunts that you need to charge the battery pack to 'full' a couple of times per month, so that the units can stay calibrated based on full charge being equal to 100%. I noted on the chargery unit, that you can individually calibrate the shunt for, both the...

And another update to my design..getting closer to finalised :)

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...

All mosfets are closed. Only 16 mosfets are opened on signal. Incoming amps =128A. This splits into two, giving a top rail of 64A. The second leg 64A, splits into two giving two 32A legs.... and so on. The signal from the lowest cell, will activate one cell on the top rail, which feeds one cell...

This is the best post i have come across. Someone with actual experience, stating that the battery packs never needed rebalancing again. YAHOOOOO (y)(y)(y)(y).....unlike, yes , you should check them every 6 months etc. Edit....incidentally, what is the main cause of the cell collapses you have...

@SCClockDr So does that imply that a 100mv100A shunt will be twice as accurate as a 50mv100A shunt(i dont know why i seem to have a mental block on this...lol)

I'm getting the distinct impression, that as popularity rises with these cells(across several vendors), 'lesser quality' is being slipped into the mix. I might be wrong...just a feeling i'm getting, the more threads i read lately???