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Video explaining my problem with my install

CHEAPEST FIX FIRST.... I will try the new thicker cables tomorrow. Just seems funny that the supplied cable from the manufacturer is not usable:unsure:... Would not everyone who bought this battery be having the same issue? Honestly i figured something shook loose in shipping and that is why i posted this in the first place. Figured you guys would know.

Hope to get it going. I would like to add 2 more of these batteries in the future.
 
You can use a 100 watt incandescent light bulb to prime the caps. No need to spend money if you can sacrifice an old lamp
Be careful 48 volts is slightly dangerous
 
The small Anderson looks like a 50 amp rated size. The larger looks like a 150 amp rated size. The inverter spec says 160 amps max which could be easily done with a startup motor surge.

I have 4 kW 48v inverter and use 350A Anderson connectors and 2/0 (00 gauge) Excelene welding cable.

Cable gauge depends on your run length. You can look it up with many on-line wire calculators and would go for no more then 0.08 milli-ohms per foot which is 2 watts of heat generated per foot at 160 amps. For 10 feet that would be 0.08 milli-ohms x20 feet (+ and - cable lengths) = 1.6 milliohms total cable resistance with 0.26v drop at 160 amps. The real consideration is cable heating for a 48v system. 80 milliohms per 1000 foot is 2/0 (00 gauge) cable. Imagine that!

I still have a problem with appearance of the battery terminals on the inverter. They look too small and too close together to handle 160 amps.
Good luck on trying to put 2/0 terminal lugs on those little inverter screw terminals.

The more wire voltage drop, the worse the overall efficiency as the inverter draws more amperage to make the same power on a lower input voltage. Sounds like you may be limited by the largest cable terminal lug that fits on the inverter terminals.
 
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NMC is not as safe as LiFePO4 as NMC are more prone to thermal runaway. Other is the BMS potentially skimping on series MOSFET breakdown voltage spec. Many have 60v breakdown MOSFET's. The NMC's are a bit higher voltage at maximum 4.2v charging per cell. With 14s that gets close to 60vdc maximum battery pack voltage.

I did notice the battery spec has 63A breaker and 65A BMS. With the picture posted of BMS it looks like the typical BMS sold on Alibaba. So battery is going to limit to a little over 2,500 watts.

For that battery you only need #6 wire for 0.5v drop on 10 feet of power cable. Still think the Anderson connector should be next size up then one installed on battery pack.

My guess the battery is 26 16650 cells in parallel X 14 series stacks for total of 364 cells. Possibly 18650 cells.
 
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I usually derate a commodity bms by .5 but because somebody selected that bms for that application I'll be generous.

52.5 nominal volts * 60 amp * .66 bms de-rate = 2079 watts dc continuous.
2079 watts continuous dc * .85 inverter efficiency = 1767.15 ac watts.
3 of those units in parallel would be a good match for that inverter.
 
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Under-gauge wire should not affect the inverter when booting under minimal load. I’m betting on a bad connector and/or broken cable. Remove the old cable and measure the resistance while wiggling along the entire length. When the resistance changes you found the bad spot.
 
Pretty sure putting heavy guage wire and big honkin anderson connector in the current path is just going to make the bms trip more efficiently.
 
Has anybody noticed that the existing connector donates what the unit is capable of? It would be hard to assume that the manufacturing company would make such a grave mistake.
 
Craig said:
I've got a 6 pack of your favorite beer that it is not the cables.
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I was wondering that too. The voltage on the MPP could have been brought low by an MPP short, but figured probably not as the cables weren't smoking.

Could be the cables (hope you have expensive tastes @ghostwriter66 ? ) , it would just take some sort of enamel (aluminum oxide is an insulator) on the wire between the end connectors. But it was odd it worked from the switch going on/off rather than bouncing the cables around. Could be anything from the cables to the batteries: an internal connector, voltage sensor on the BMS causing it to cut out, relay on the switch, etc. Fortunately the OP has his trusty meter so can trace the voltage back as needed. Or, if it's under warranty just have them ship a new one.
 
Craig said:
I've got a 6 pack of your favorite beer that it is not the cables.
Click to expand...

Looks like I'm going to be drinking well after work tomorrow .... ITS GOING TO BE THE CABLES ... LOL ... first class of my first year of EE school the professor said - always check the cables -- and its 95% of the time a cable or connector -- don't tell anyone how you fixed it - just have them think of you as a brilliant engineer .... BUT for the other 5% of the time it's not a cable or connection - the next 4 years we will be teaching you trouble shooting and design .... LOL
 
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1. Did not buy it from Ian; email is from someone else.
2. Do we know the model# of the all-in-one unit? Is it 5kw (which requires a 200ah battery pack)? This box is 79ah.
3. Forced to watch 2 boring videos instead of a couple fact-filled paragraphs. Did OP ever watch a Will Prowse video - at least *try* to imitate the master.
4. Flimsy cables evident in video #1.
--
 
ghostwriter66 said:
first class of my first year of EE school the professor said - always check the cables -- and its 95% of the time a cable or connector -- don't tell anyone how you fixed it - just have them think of you as a brilliant engineer ....
Click to expand...
Better to Remain Silent and Be Thought a Fool brilliant engineer than to Speak and Remove All Doubt
 
<tapping foot....impatiently awaiting today's video...Will ghostwriter66 get free beer? Will Craig have to break open the piggy bank? What will smoothJoey sing on the Kareoke machine? Is it the cable or <dunt dunt don dah> is it something far more nefarious! Will Randerson finally have 54 volts??? Aggg... the suspense is killing me!!!>
 
svetz said:
<tapping foot....impatiently awaiting today's video...Will ghostwriter66 get free beer? Will Craig have to break open the piggy bank? What will smoothJoey sing on the Kareoke machine? Is it the cable or <dunt dunt don dah> is it something far more nefarious! Will Randerson finally have 54 volts??? Aggg... the suspense is killing me!!!>
Click to expand...
Dammit svetz, now I have to read 67 posts and watch videos to understand what the heck this is all about. I guess I'll have to put off binge watching Money Heist for a bit tonight.
 
So I finally watched the video.
The mpp display doesn't turn off when the mpp switch is opened.
Not sure what that means.
 
My take: There is no problem with any single component. Each is operating as designed. The problem is with the system as a whole: it is a very poorly matched battery bank and inverter combination. The group has collectively already arrived at this conclusion (see below).

@randerson - you don't need to return anything, you need to buy more battery capacity, put it in parallel and size your battery bank to inverter wires appropriately. Pre-charging your capacitors is a good idea so that the one time you connect the battery bank to the inverter it is a smooth(Joey) event.

Also, pay attention to the post pointing out that you think you have a LiFePO4 battery but you really have a Li-ion NMC battery...

DASH said:
I would go over all the specifications of the Mpp and the Battery to make sure they are compatible
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smoothJoey said:
3 of those units in parallel would be a good match for that inverter.
Click to expand...
RCinFLA said:
Your battery cables?? Really!
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From the manual, the OP has a 5kW inverter (10kW surge) that recommends at least a 200Ah battery bank and 1/0 AWG cable that can handle the 220A. The OP connected a 79Ah battery with 6 AWG cable and a 60A (65A) BMS (depending on BMS label or BYD site).

Craig said:
Cables are small but I think there is something internal in the battery like a BMS that is overcurrent limiting the output.
Click to expand...
Craig said:
My theory is that your switching on and off of the battery is slowly charging the caps each time until they are full enough to not trip the BMS or whatever is causing the problem.
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Sounds reasonable. How much inrush current will there be to charge the caps to support the 5kW/10kW surge inverter? Better than 60-65 amps? You won't be buying anyone any beer.

smoothJoey said:
Pretty sure putting heavy guage wire and big honkin anderson connector in the current path is just going to make the bms trip more efficiently.
Click to expand...
I agree.

smoothJoey said:
@randerson https://diysolarforum.com/resources/inverter-disconnect-switch-with-precharge.60/
Click to expand...
Or just flip the switch on and off repeatedly like a lightswitch rave.
 
svetz said:
<tapping foot....impatiently awaiting today's video...Will ghostwriter66 get free beer? Will Craig have to break open the piggy bank? What will smoothJoey sing on the Kareoke machine? Is it the cable or <dunt dunt don dah> is it something far more nefarious! Will Randerson finally have 54 volts??? Aggg... the suspense is killing me!!!>
Click to expand...

Does the OP @randerson NOT realize that my 12 hour shift ends at noon (CDT) ... I had already laid out my detailed drinking schedule to coincide with drinking good beer with the steak fajitas these guys cook up every Friday afternoon out here ...

This is going to royally piss me off if the OP does not get us an update ...

Holy Cow - how long does it take just to slap some larger cables on an Anderson connector and prove me right ... ??!!! THIS is not helping me with my Anger Management issues that "may" have been one of the reasons they transferred me from LA to the desert SW .... But honestly - we set through 5 1/2 minutes of "switch on - switch off - switch on - switch off" .. we deserve an answer !!
 
ghostwriter66 said:
Does the OP @randerson NOT realize that my 12 hour shift ends at noon (CDT) ... I had already laid out my detailed drinking schedule to coincide with drinking good beer with the steak fajitas these guys cook up every Friday afternoon out here ...

This is going to royally piss me off if the OP does not get us an update ...

Holy Cow - how long does it take just to slap some larger cables on an Anderson connector and prove me right ... ??!!! THIS is not helping me with my Anger Management issues that "may" have been one of the reasons they transferred me from LA to the desert SW .... But honestly - we set through 5 1/2 minutes of "switch on - switch off - switch on - switch off" .. we deserve an answer !!
Click to expand...

I ran out of popcorn.
 
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