Batteries Died, and Crazy Over Voltage Systems

[KenEhresman]

So pretty sure these old Lifelines are shot... Ordered 8 new ones will be in tomorrow.... but I'm concerned because my SW4024 invert er #2 seems to charge bulk up to 31V then cuts out with an error.... Not sure if this is because the batteries are shot? Couple questions for those knowledgeable...

1. When batteries fail, will the SW4024 drift high and go into an over charge condition?
2. Banks are generating heat now, certain sign they are dead...
3. Under moderate load of about 10 amps on the 115V panel, they crash from 27V to under 24 in less than 2 minutes....

So BEFORE I hook up 4500 dollars worth of new batteries, what suggestions do you have to help me verify we are not introducing new batteries to a potential battery eating inverter problem..

Anyone document the best settings for the SW4024 units using lifelines on all the config menus for the inverter/charger other sections?

P.S. IN order to not keep tripping the Inverter, I turned the charger amps down to 2 amps on each inverter since I am on shore power and don't really need to be charging anyway if i'm just cooking worn out batteries

[Gil_J]

Bad batteries can certainly drive a charger nuts, especially if you have a shorted cell.

You could isolate the bad batteries and test your charger. Given you'll have new batteries today, it's not worth it. If the charger is bad you will find out when you install your new batteries. Depending on who converted your coach, this could be a good time to rewire your bank. Some converters used the battery terminals as buss bars with 4 and 5 connections on a battery terminal.

Unless you dry camp, 8 batteries are far too many. I know it's too late now and your battery salesman is smiling, but those that don't dry camp can have an effective bank with 4 batteries.

I'll post charger settings a little later.

[Gil_J]

Ken,

Here's the settings I recommend for your 8 battery (~1,000 Amp) 24 Volt battery bank:

-- Absorption charge time: Not to exceed 180 minutes. You can opt for much less if you operate pole-to-pole.
-- Maximum charge amps (AC): Not to exceed 20 amps if you use both chargers. The general rule of thumb is that charging current should be limited to no more than 20% of the capacity of the bank.

Make sure your absorption and float charge voltages are those specified by Lifeline.

I hope this helps. BTW, how far from these settings were yours?

[KenEhresman]

Hi Gil, Thanks for the response... these settings were pretty close... the absorption is 3 hours, and rate is 28.8, float is a bit less, and amp was set at 15 per inverter...

We dry camp over 75 % of the time time we are mobile, hence the need for 8 or MORE batteries lol... Battery sales person in this case won't be smiling, because we will likely work these like most never will... these were delayed shipping to us so they tell us they will be VERY fresh...Tom at Trans Specialist got the order at 5K or just south of that a bit shipped for 8..... they will get a work out... I will review lifeline specs and match with recommendations and setup the same in the inverter charger menus... thanks!

FYI and FWIW, if anyone ever encounters this similar issue, i.e the bulk charge rate jumps rapidly to 30+ volts and trips multiple times, use the menus to set the charge rate down to 2-5 amps from the 15 and then you will be able to run on AC power... at 15+ amps, it just kept boiling off the batteries (i'm sure a shorted cell or more) and tripping into fault on one bank... Converter is Feather lite, 2000 conversion using SW4024 units...

[travelite]

Hi Ken,

Is that price for eight 4D's or 8D's?

Unfortunately a battery is only as good as it's weakest link. With six cells in series it's the weakest cell that determines the SOC and the capacity of the battery. A weak cell has higher internal resistance which shows up as an overvoltage condition when charging along with more heat. As you've discovered the Trace SW4024 protects itself from battery overvoltage by shutting down. The voltage level that triggers a shutdown is configurable under menu heading 9 "Inverter Setup". The parameter is "Set High Battery Cutout". The default is 32 VDC but there's really no reason to change it.

[GoneCrazy]

Hey Ken,
Noticed that Your Location says Pontiac. Is that Mi ?
Safe Travels,
Rocky

[KenEhresman]

Hi Rocky, That is Pontiac Illinois, I get that alot.... I can tell you where it is, but easiest to just map it... in the cornfields lol... but hey, I'm the only person here with a Prevost lol....

Hi David, that price 4970 was for 8 of the 4DL direct replacements of my units.... Ordered from Trans-Specialties

[Gil_J]

Ken,

Lifeline's Bulk/Absorption voltage should be 28.6V, so you're close. The Float voltage should be 26.6V.

[travelite]

Thanks Ken,

The last time I bought Lifelines was in January of 2012. I paid $448 per GPL-4D and I bought six from Trans Specialists.

[GoneCrazy]

Hey Ken,
Nothing wrong wit a lot of cornfields around Ya. I used to live in Pontiac Mi , Was just curious. I would rather be in the Cornfields now than That City.