• Have you tried out dark mode?! Scroll to the bottom of any page to find a sun or moon icon to turn dark mode on or off!

diy solar

diy solar

New Pytes V5 battery rack shows voltage when off

fwunder

fwunder

Solar Enthusiast
Joined
Jul 18, 2020
Messages
170
I'm just beginning install of my new system. Brand new Pytes V5 battery bank ( 3 ) pictured below. With all batteries off I am measuring 52.1 volts with meter. I'm thinking I shouldn't hook it up.

Wazzup with that? I went through startup and shutdown procedure just to make sure and the bank still measures 52.1

I don't see anything in the manual to explain.

Thanks for any info!


IMG_1297.jpeg
 
In the off position, it may still present a voltage through the pre-charge circuit, i.e., when you connect to the inverter terminals, there should be no spark because there's a resistor in the circuit.

Have you read the manual for the startup procedure for the batteries?
 
I did read it several times. What startled me was when I went to hook up to bus bar ( Lynx Power In ) there was a spark. A small one, but that’s when I backed off and measured battery bank voltage. Thanks.
 
fwunder said:
I did read it several times. What startled me was when I went to hook up to bus bar ( Lynx Power In ) there was a spark. A small one, but that’s when I backed off and measured battery bank voltage. Thanks.
Click to expand...

If there was full battery voltage/power available in this case, I would expect a notable arc-welding level spark. A small spark that causes no damage to the surfaces strongly suggests there is a resistance in the circuit.

This sound normal unless there is documentation indicating there should be 0V at the terminals when off.
 
Something's not right. This time I disconnected both inverters from bus bar and hooked up battery bank. I then attached Inverter L2. No spark. I then touched Inverter L1 to bus and big spark. Again, battery bank is off but showing 52 volts. I can't find any Pytes documentation that shows battery bank voltage when off.

 
fwunder said:
Something's not right. This time I disconnected both inverters from bus bar and hooked up battery bank. I then attached Inverter L2. No spark. I then touched Inverter L1 to bus and big spark. Again, battery bank is off but showing 52 volts. I can't find any Pytes documentation that shows battery bank voltage when off.

Click to expand...

Yeah. That's more than I would expect. I think it's worth contacting the dealer/Pytes.
 
LOL. Thanks for your help. Will be interesting to see if it can be worked out without shipping back.

The system is working perfectly with the two batteries.

Now I need to find the pinouts for the Victron BMS type A Cable so I can make up a cable for the Pytes-Cerbo.
 
fwunder said:
LOL. Thanks for your help. Will be interesting to see if it can be worked out without shipping back.

The system is working perfectly with the two batteries.

Now I need to find the pinouts for the Victron BMS type A Cable so I can make up a cable for the Pytes-Cerbo.
Click to expand...
I've been eyeballing buying a new 10-stack of these batteries. I'll be interested to know you make out with these.
 
Learning the hard way...

So, Pytes says I blew the power board in the first battery in the bank by not having a battery disconnect switch between batteries and inverter(s) before I connected to bus bar ( which inverter(s) were already connected to ). Say charged capacitors in inverter(s) blew the board even though everything was off and brand new. I am still trying to wrap my head around the logic and how to avoid it in the future, other than a battery disconnect switch? I thought the pre charge resistor was to prevent rush from batteries to inverter(s), not the other way around and that the Pytes has pre-charge circuitry built in. Yeah, I'm confused.

It is a user replaceable part. That's the good thing.
 
fwunder said:
Learning the hard way...

So, Pytes says I blew the power board in the first battery in the bank by not having a battery disconnect switch between batteries and inverter(s) before I connected to bus bar ( which inverter(s) were already connected to ). Say charged capacitors in inverter(s) blew the board even though everything was off and brand new. I am still trying to wrap my head around the logic and how to avoid it in the future, other than a battery disconnect switch? I thought the pre charge resistor was to prevent rush from batteries to inverter(s), not the other way around and that the Pytes has pre-charge circuitry built in. Yeah, I'm confused.

It is a user replaceable part. That's the good thing.
Click to expand...

Sounds like moist steamy bullshit.

They don't want to accept responsibility for either a bad design or a factory defect.
 
OK, riddle me this...

I'm just trying to make any sense out of Pytes reasoning.

I did not measure voltage @ inverter terminals prior to connecting to bus. These are pre-programmed Victron inverters so they were powered up before shipping. Is it possible there was residual capacitor voltage @ the inverter terminals with the unit off? Even so, how does that create a surge that gets past battery switch and toasts a board? There is also a t-class fuse between the bus and the battery bank. As Mulder would say, "The truth is out there".

Oh, I should add that that are no AC connections yet so no chance of charging current.
 
As an owner of Pytes batteries, I'm disappointed with their BS response. You did nothing wrong.
 
Because I think there is some interest in how Pytes handles this I will pass along the progress. Personally, I think they should have just insisted on sending me a new battery and taking the "damaged" one back at their expense, no questions asked. I would want to examine in lab. Anyway...

Yesterday afternoon they asked for the following verbatim in addition to a video link on how to replace power board :
  • Photos of batteries, installation, and damaged battery SN
  • Photo of multimeter voltage measurement on battery terminals, both with switch ON and OFF
  • Photos of multimeter voltage measurements of internal battery packs
I supplied the following photos:
  1. Battery bank before any installation
  2. Battery bank in parallel w/T-class fuse before connection to Lynx Power In bus bar
  3. Battery bank with damaged battery disconnected ( using two batteries ) operational. Note T-Class fuse now moved to bottom battery Master.
  4. Battery voltage switch OFF
  5. Battery voltage switch ON
  6. Internal battery pack voltage RIGHT
  7. Internal battery pack voltage LEFT

IMG_1295.jpeg

IMG_1297.jpeg

IMG_1300.jpeg

  • Battery voltage switch OFF

IMG_1307.jpeg

  • Battery voltage switch ON

IMG_1308.jpeg

  • Internal battery pack voltage RIGHT

IMG_1313.jpeg

  • Internal battery pack voltage LEFT

IMG_1312.jpeg
 

Attachments

  • IMG_1313.jpeg
    IMG_1313.jpeg
    1.2 MB · Views: 4
  • IMG_1300.jpeg
    IMG_1300.jpeg
    780.8 KB · Views: 1
Last edited:
fwunder said:
OK, riddle me this...

I'm just trying to make any sense out of Pytes reasoning.

I did not measure voltage @ inverter terminals prior to connecting to bus. These are pre-programmed Victron inverters so they were powered up before shipping. Is it possible there was residual capacitor voltage @ the inverter terminals with the unit off?
Click to expand...

No. Capacitors discharge pretty quickly.

fwunder said:
Even so, how does that create a surge that gets past battery switch and toasts a board?
Click to expand...

Everything about their response fails all logic tests. It's blindingly obvious they're aware of an issue, and it's almost certainly the result of a component or quality issue.

Their stated reasons for this fault are impossible. The presence or lack thereof of a battery disconnect switch is irrelevant, and their claim that you damaged it as a result is asinine.
 
You must log in or register to reply here.

Similar threads

F
Pytes V5 charge parameters for Victron 250/100?
Replies
5
Views
498
Johnhallycr
Johnhallycr
S
ECO-Worthy 5000W to Pytes V5 BMS RS485 Communications
Replies
4
Views
459
SolarUKWM
S
D
How should I troubleshoot a Pytes V5 battery pack?
Replies
5
Views
673
dustyPanels
D
S
Top-balancing Pytes V5 with Ecoworthy All In One?
2
Replies
26
Views
613
fcopurico
F
fwunder
Getting to know my Victron Cerbo GX
Replies
15
Views
396
fwunder
fwunder

diy solar

diy solar
Back
Top