Author Topic: Battery bank won't hold charge  (Read 165 times)

Gearjam

  • Newby
  • *
  • Posts: 5
Battery bank won't hold charge
« on: June 20, 2020, 10:16:33 PM »
Soon as the sun goes down volts drop. Within an hour or two my batteries are at 50% 12.1v. Had a solar guy Chechen my connections of combiner box into e panel, batteries into e panel and classic 200 into e panel. Alls well. He was a grid tie solar guy, didn't know much about batteries. Talked with John Paris at tech support and he mentioned something about batteries discharging but can't remember what he said. Maybe he'll read this post. I bought a brand new charge controller thinking I burnt the old one out but it didn't resolve the situation. Any advice????

ClassicCrazy

  • Hero Member
  • *****
  • Posts: 2582
Re: Battery bank won't hold charge
« Reply #1 on: June 20, 2020, 10:52:34 PM »
What kind of batteries are they and how old are they - also how many and how are they configured in your system ?

Larry
system one
Classic 150 , 5s4p  Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system two
Classic 150 ,5s 135 watt Kyocero , 16s Calb 100AH LiFePO4 , Outback VFX 3648 inverter
system three
Midnite KID MPPT 24 DC in to  12 volt AGM batterie

mike90045

  • Hero Member
  • *****
  • Posts: 789
    • The Ranch (via facebook re-direct)
Re: Battery bank won't hold charge
« Reply #2 on: June 21, 2020, 12:47:18 AM »
My first guess is the batteries are sulfated, and will need replacing.

What's the Ah of the batteries ?   Battery voltage ?
Solar panel wattage ?
http://tinyurl.com/LMR-Solar

Classic 200| 2Kw PV, 160Voc | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph )| Listeroid 6/1, st5 gen head | XW6048 inverter/chgr | midnight ePanel & 4 SPDs | 48V, 800A NiFe battery bank | MS-TS-MPPT60 w/3Kw PV

Gearjam

  • Newby
  • *
  • Posts: 5
Re: Battery bank won't hold charge
« Reply #3 on: June 21, 2020, 08:50:26 AM »
6-12v V Max Tank AGM 125 ah wired in parallel. All new to replace old battery bank of same manufacturer. Was having same problem with old battery bank. Started slowly getting worse after I added an e panel. Accident wired negative battery from shunt into my classic 200 into the PC neg instead of the bat neg. Thought maybe I burnt up the classic so ordered another and having same problem. 12v system. 4 Renogy 255w 12v panels into combiner box breaker and 4 300w 24v Renogy panels into a separate breaker.
« Last Edit: June 21, 2020, 09:10:15 AM by Gearjam »

mike90045

  • Hero Member
  • *****
  • Posts: 789
    • The Ranch (via facebook re-direct)
Re: Battery bank won't hold charge
« Reply #4 on: June 21, 2020, 10:08:10 AM »
You have 150A to recharge 750ah of battery.   That should be OK, if your loads are not high and you have enough usable sun hours.

But 6 AGM batteries in parallel is really hard to keep the load shared evenly
 read this about the battery wiring   http://www.smartgauge.co.uk/batt_con.html
http://tinyurl.com/LMR-Solar

Classic 200| 2Kw PV, 160Voc | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph )| Listeroid 6/1, st5 gen head | XW6048 inverter/chgr | midnight ePanel & 4 SPDs | 48V, 800A NiFe battery bank | MS-TS-MPPT60 w/3Kw PV

Gearjam

  • Newby
  • *
  • Posts: 5
Re: Battery bank won't hold charge
« Reply #5 on: June 21, 2020, 08:25:42 PM »
Thanks. I've read the article and I use method 2 where my leads come from opposite ends of the battery bank. I'm not sure wiring my bank by example 3 or 4 would solve my problem. I think most people running a 12v system wire their banks the same without having my problem. Ive got a Magnum 48v inverter/charger I want to install and wire in my generator but I think I have to get this battery issue sorted out first. Do you believe if I wire my batteries as in the 3rd and 4th example it would solve this issue? Thanks again.

mike90045

  • Hero Member
  • *****
  • Posts: 789
    • The Ranch (via facebook re-direct)
Re: Battery bank won't hold charge
« Reply #6 on: June 22, 2020, 02:35:05 AM »
Just stay with the wires you have. 

I suggest to always start with a set of "beater" batteries, cheap 6v golf cart batteries, and learn all the settings and mistakes on them, instead of with a $2,000 set of sealed AGM batteries.

With sealed AGM, you are never sure of their charge state, and you have to be careful about overcharge and venting gas
http://tinyurl.com/LMR-Solar

Classic 200| 2Kw PV, 160Voc | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph )| Listeroid 6/1, st5 gen head | XW6048 inverter/chgr | midnight ePanel & 4 SPDs | 48V, 800A NiFe battery bank | MS-TS-MPPT60 w/3Kw PV