Battery questions

[RRTom]

I just had the house batteries replaced with AGM's. I checked the built in "battery control" and voltage was reading 8.85. This was one week after install. I started the generator to exercise it, the A/C and charge the batteries. The gen ran very rough for about a minute and half, and then stopped. I will let the dealer sort the gen problem out since it's still under warranty.

I plugged in the 50 amp this morning and immediately checked the "battery control" and got a reading of 13.3. I left it alone for a while and it stayed right in that range. I have now unplugged the 50 amp and the voltage dipped to 12.9, did the battery disconnect, and I will check again in an hour. I have been told that leaving the 50 amp plugged in while parked next to the house will damage my batteries.

Also, when i do the battery disconnect, and then reconnect, the radio comes on by itself. ???

I am "electrical system illiterate" and would appreciate any possible explanations for this.

[Gjac]

wa8yxm said: Years ago there was a converter. Magnetek 6300, among others, that was very popular in RV's.. this used a "Ferroresonate" transformer to more or less control the voltage out.. Not all that good at it.. IT was a converter/power supply putting out raw unfiltered rectified AC for lights up to around 35 amps and about 3-5 amps DC to the batteries, which filtered it, for loads that like a clean diet. (Radios for example)
Voltage regulation was not that great and when the batteries were "Full up" It kept right on pushing (Overcharging) and woudl often boil batterie dry in 1-3 weeks.
I have heard this said for years on here and for the life of me I never understood this logic. I still have the old Magnateck 950 and it has never charged more than 13.6 volts when new and now charges at 13.2 volts after 25 years of use. How does this voltage boil the batteries dry in 1-3 weeks?

[down_home]

I don't have AGMs but the lead acid Trojans on board when first installed required the generator running several hours on the road to get to just float charging.
Just plugged in wouldn't do it. Our coach is a 2005 though.

[wa8yxm]

Some facts and myths and the root of the myth.

I hear a lot of folks "You should not leave the batteries connected full time when on shore power" or "You should not be plugged in full time"

Years ago there was a converter. Magnetek 6300, among others, that was very popular in RV's.. this used a "Ferroresonate" transformer to more or less control the voltage out.. Not all that good at it.. IT was a converter/power supply putting out raw unfiltered rectified AC for lights up to around 35 amps and about 3-5 amps DC to the batteries, which filtered it, for loads that like a clean diet. (Radios for example)
Voltage regulation was not that great and when the batteries were "Full up" It kept right on pushing (Overcharging) and woudl often boil batterie dry in 1-3 weeks.

They don't make it any more.

Modern converters come in 1-2-3-3+ stages (That's in increasing order of Fantastic) The parallex 7300 is a single stage.. Now these can be tricky because if they are set properly then the battery only gets to about 90-95% charge. Not great but not all that bad.. Set a bit high. Well see Magnetek (By the way Parallex bought Maganetk out or so I'm told)...
The Paralle 7300T (yes just add T for Two) is a Two stage charger (Sorry can't resist a song reference. Tea for Two and Two for Tea....)
It, when first powered on, starts a timer and goes into "BULK" mode till the timer times out then it drops to float Bulk is a slightly higher voltage (14.6?) to push more current into the battery Float is about 13.6.

Then we have modern 3-stage.. and 3-stage plus

These monitor battery voltage and current draw.. They go into BULK when the batteries are low to quickly fill 'em to around 90%. then drop to Absorption (Still higher than 13.6 but lower current) and finally drop to float....

Now the PLUS models also do equalization.. Some under manual control some (Progressive Dynamcis wizard) does a sort of automatic equalization after I THINK 20 hours of float (NOTE The word THINK. might be off).

By the way I highly recommend Progressive Dynamics Wizard controled converters.


ALl of these.. You can plug in full time

MINIMUM time to recharge batteries is six hours.. Might be longer

[RRTom]

The reply to my question to the manufacturer of my converter:

Hello,

This converter is designed to charge both lead acid and AGM batteries…no adjustments to be made

No worries about it overcharging

[RRTom]

time2roll wrote:
8A27M looks like EP Deka battery and the voltages you have are fine.

Charging voltages at bottom of p11.

The sheet has GELL and AGM. Mostly just read the AGM sections.

Thank you time2roll and all the others who have helped me so far. So, if we are at a good float range, then leaving the 50AMP plugged in should not harm the batteries? As long as I check the voltage periodically?

[time2roll]

8A27M looks like EP Deka battery and the voltages you have are fine.

Charging voltages at bottom of p11.

The sheet has GELL and AGM. Mostly just read the AGM sections.

[RRTom]

time2roll wrote:

RRTom wrote:
OK, I left the 50 amp plugged in overnight. The reading this morning is 13.4. Is that in the proper range?

Yes, the batteries like this float voltage to be on for maintenance while the RV is not in use.
This should be described in the battery charging and maintenance specifications. If you post the exact batteries this can be confirmed.

Generally the PD9270 is good for all flooded and AGM batteries.

time2roll: The batteries are Roadhawk Deep Cycle Predator RV AGM, part #8A27M

EDIT:

These are rebranded Deka batteries. Specifications are:
Deka 8A27 (8A27M) AGM Battery Specifications:
Nominal Voltage: 12V
Amp Hour Capacity @ 20 hr rate: 92 a/h
Reserve Capacity @ 25 amp discharge rate: 185 mins
BCI Group Size: 27
Marine Cranking Amps @ 32* F: 900 amps
Cold Cranking Amps @ 0* F: 580 amps
Weight: 63 lbs
Length: 12 3/4 in.
Width: 6 3/4 in.
Height: 9 7/8 in.
Terminal Type: dual terminals (autopost and stud)

[time2roll]

RRTom wrote:
Another question: If the battery is "disconnected" at the switch, should the interior ceiling lights still work?

Generally the lights are powered by 12 volts. This can come from the batteries when the switch is on. Or the power can come direct from the PD9270 converter when connected to a power source.

If you unplug and turn the battery switch off all lights should go out.

[time2roll]

RRTom wrote:
OK, I left the 50 amp plugged in overnight. The reading this morning is 13.4. Is that in the proper range?

Yes, the batteries like this float voltage to be on for maintenance while the RV is not in use.
This should be described in the battery charging and maintenance specifications. If you post the exact batteries this can be confirmed.

Generally the PD9270 is good for all flooded and AGM batteries.

[RRTom]

dougrainer wrote:
I hope your Genset and Motorhome are less than 30 days old. If NOT, then the odds are YOU will be paying for the Genset problem. From your description of the Genset problem your GASOLINE has gone bad in the Carb and gummed it up. This is NOT a warranty repair. RVer's need to run their Gensets twice a month for at least 30 minutes and also use STABIL type additive in the Gasoline to prevent Genset Carb problems. Doug

I was thinking that might be the problem. But, we have had the genset looked at at least once by the dealer because it twice stopped running while driving. The dealer couldn't find the problem. So, hopefully that will be my out.

[RRTom]

OK, I left the 50 amp plugged in overnight. The reading this morning is 13.4. Is that in the proper range?

[dougrainer]

I hope your Genset and Motorhome are less than 30 days old. If NOT, then the odds are YOU will be paying for the Genset problem. From your description of the Genset problem your GASOLINE has gone bad in the Carb and gummed it up. This is NOT a warranty repair. RVer's need to run their Gensets twice a month for at least 30 minutes and also use STABIL type additive in the Gasoline to prevent Genset Carb problems. Doug

[dougrainer]

From PD website. Doug



What Type of batteries are recommended?
Deep cycle Flooded Lead Acid, AGM , Gel Cell
Battery size should not be less than the converter size in AMPS.

Also, you MUST---MUST monitor your new AGM battery/s. DO NOT let them go dead. AGM batteries do not take going completely dead and then recharging. Deep Cycle lead batteries can handle that. AGM's cannot. Doug

[RRTom]

Matt_Colie wrote:
RR,

Something you need to do is locate your converter/charger and the paper work (documentation) that should have come with it. Then come back and tell us about it.

Yes, all of the posted numbers say you have a problem, but how much of a problem remains to be seen.

I have a very old coach, and I leave it plugged into the 50 as long as it is in range. I have a good system and I have zero problems.

Matt

My converter is a Intellipower PD9270 with built-in Charge Wizard. Output 13.6 VDC, 70 AMP."The Charge Wizard microprocessor constantly monitors the battery voltage and automatically adjusts the converter output voltage to provide the proper charging voltage for fast recharges and long-term maintenance." But it doesn't mention AGM batteries. I sent an email to the company asking if it could be used with AGM's.

Another question: If the battery is "disconnected" at the switch, should the interior ceiling lights still work?