So I've got a 2004 pioneer 18t6 with a low end, already replaced converter (original blew out on me), and I'm running into the typical problem of recharging my (2) exide group 24 batteries taking too long.I use a meter and check the voltage, both when charging and not charging, and from what I have gathered, the batteries are fully charged at 13.3 when the shore cord is plugged in (sound right?) and 12.6 when not connected and disconnected for more than a day (sound right?).It takes about 5-7 hours to get my batteries from 12.1 (not connected ) 12.8 (soon as I connect) to 13.3, so I'd like to get a stand a lone battery charger to hookup from the genset to batteries. My question is - if i want to use 12v DC power while charging my batteries, can I plug in the shore cord and battery charger at same time to basically do the same thing that I'm doing when I plug the shore cord (I don't have an inverter/converter, just basic converter) with just a 2k genny?Also how do I charge both batteries at same time with one battery charger, and additionally the shore cord plugged in. I know I have 2 outlets on genny -1 for shore and 1 for battery charger, but does the charger allow charging of 2 batteries. If my batteries are wired in parallel, would I be able to just hook up to one?

Connecting -both- the converter and a charger to your batteries would be, interesting. In a "that was interesting" kind of way.You system is taking longer to charge then it shouldPersonally I would ripe the converter you installed out and put at least a 40 amp Progress Dynamics with Charge Wizard in.

It would be helpful if you name the converter that you presently have.To answer some of your questions: Yes, you can plug your shore power cord into the generator and use a stand-alone battery charger at the same time. You're only limited by the output of the generator. You don't have to use the charging 12V port on the generator. In fact, most are limited to <10amps. You can plug a stand-alone battery charger into any AC receptacle that is handy. You would be well advised to connect both your batteries in parallel and leave them like that, both for charging and for use. You gain power by the Peukert effect. There is nothing wrong with using your 12V system while the batteries are charging. It will just take longer to reach an adequate charge. I would suggest that there are improvements that you could make: using two 6V GC2 batteries will give you more reserve power and are easier to keep in a good state of health. Installing a new, adequate converter will spare the expense of a stand-alone charger and serve you better in the future, resulting in more average time between battery swaps. You should be doing an equalization charge routine with all lead acid batteries. It will result in longer battery life. You don't mention a disconnect switch for your 12V system. You should have one. Increasing the wire size from your present converter to the batteries will result in somewhat faster charging.Finally, a small solar system is the best battery charging and seamless power plant you can find. If implemented correctly, it will replace your generator, carrying gas, and the noise endured. When the trailer is in storage, no extraordinary methods are needed to keep your batteries charged and ready to go.Best of luck with your 12V system!

There really isn't anything magic about charging deep cycle batteries. Here is what PROGRESSIVE DYNAMICS says about charging DEEP CYCLE MARINE TYPE batteries... We follow this guideline pretty close in our travels... "Progressive Dynamics ran this test on the amount of time it took a PD9155 (55-amp) converter/charger set to three different output voltages to recharge a 125 AH (Amp Hour) battery after it was fully discharged to 10.5-volts. 14.4-VOLTS (Boost Mode) – Returned the battery to 90% of full charge in approximately 3-hours. The battery reached full charge in approximately 11 hours. 13.6-VOLTS (Normal Mode) – Required 40-hours to return the battery to 90% of full charge and 78-hours to reach full charge. 13.2-VOLTS (Storage Mode) – Required 60-hours to return the battery to 90% of full charge and 100-hours to reach full charge." This is battery charging science at play here - not many ways to get around itMy PD9260C Smart Mode converter/charger will return my three 85AH Standard Issue GP24 Interstate 12VDC batteries to their 90% charge state in around three hours time. This happens when I am connected to SHORE POWER or running my trailer directly from my 2KW Generator using a RV30A-15A Adapter...When my three batteries get hit with 14.4VDC Charging DC Voltage they will immediately start demanding around 53AMPS DC Current from PD9260C Smart Mode Converter/charger unit. This DC current starts dropping back in around 15 minutes as the batteries start taking on the charge and in an hours time is only drawing around 8AMP DC current while still being fed with 14.4VDC from the converter. After two hours of charging at 14.4VDC the smart mode converter/charger unit will drop down to 13.6VDC Charging mode with the DC Current now reading around 6AMPS DC. This mode will continue for another hour before attaining a 90% charge state for all three 12VDC batteries being charged together. The smart mode converter/charger may switch to 13.2VDC at this time if no load is being drawn from the battery bank. When a load is presented to the battery bank the PD9260C will autoswitch to 13.6VDC and remain at this level until the load goes away where it will again return to the 13.2VDC mode.When the trailer load reduces the battery level to around 50% charge state then the PD9260C will go into its 14.4VDC boost charge mode again and will bring the battery bank to its 90% charge state in about three hours time.This is the cycle process for my battery bank charging process using my PD9260C 60AMP Smart Mode charger.If your charging system never hits the 14.4VDC mode then it will take many hours to attain a 90% charge mode status as indicated in the above Progressive Dynamics stated process. Most folks think you can force many AMPS into the charging process to make batteries charge faster. I have found this to be a 'NOT TRUE' assumption. You could have a 100AMP or even a 200AMP Source of 14.4VDC Charging Voltage and each 12VDC battery will only draw 17-20AMPS of this available 100AMPS charge source while being charged. The only way to charge quicker is to raise the charging DC Voltage. The down side of doing this is the battery will develop more heat in the process and will immediately start boiling your battery fluids. This could become very unstable and could end up in the battery actually exploding on you. The BATTERY FOLKS have determined the safe charging technique is to use around 14.4VDC to charge your 12VDC Battery and this process will take around three hours time to attain a 90% charge state.I am NO BATTERY EXPERT just what I read about from folks like PROGRESSIVE DYNAMICS and TROJAN and also from my experience of charging my battery banks over the past few years.Back in the 50s the local garage would advertise a quick one hour charge as the best way to get your battery charged. They would hit the 12VDC START BATTERY with around 50VOLTS DC (or more) with around 150AMPS available DC Current. The battery would almost turn "red" on you while being charged. Batteries would also explode on you. I witnessed one blowing its top which went into the air a good 50-feet or so at a local garage doing this. Glad I wasn't leaning over the battery when it happened...Just saying....Roy Ken

At 13.3 it will take forever. You haven't said what model converter. If it's a Progressive Dynamics it may have a boost mode that goes to 14.4 and that would help a lot. You battery is never going to reach the proper specific gravity and will be damaged. If you seldom dry camp or only for a weekend a good converter may work for you.If you often dry camp for extended periods, no converter will work well for you.If you have lots of time to be on shore power a slow convert may be okIf you want faster, get a real battery chargerA real charger

Read /Google 12volt side of life and LEARN. Get yourself a 40 amp stand alone charger AND GO FROM THERE. JMO

Battery charging process with EU2000i and poor converter?

pianotuna
Nomad III
Sep 15, 2014
That particular make of converter rarely goes into "bulk" mode for charging. Sometimes it can be improved with thicker wire--but most folks replace them.
time2roll
Nomad
Sep 15, 2014
To get WFCO into boost... the voltage AT THE CONVERTER must sag below 13.2 volts during the initial charging. Unless you have six batteries and very short #2 wire connection this is just not going to happen.

Good part is that it is an easy to replace deck mount converter. Just get a deck mount PD or IOTA replacement in the 60 amp range.
Yohyatt
Explorer
Sep 15, 2014
So - I checked my trailer and I have a WF-9865 converter. So it's a 65 amp 3 stage... wonder why it's taking this long???????? Batteries are new and I checked their levels...
jauguston
Explorer
Sep 10, 2014
The recommended maximum charge voltage for a 12v battery has been changed in recent years. Most battery manufacturers now recommend a maximum charge voltage of 14.8v. Many new cars and trucks now have maximum charge rates of 15v. My Fullriver 6v AGM house batteries have a maximum charge voltage recommendation of 14.9v when in a 12v series pair Many of the newer converters have a 14.8v setting. I have two that do.
time2roll
Nomad
Sep 09, 2014
Yohyatt wrote:
I spoke to my mechanic who installed the newer converter and he thinks it's at least a 40 amp converter, so maybe the batteries aren't getting enough volts? Doesn't seem clear to me that buying a 40 amp charger will solve my problem if my converter is a 40amp.
If it is a PD or IOTA you may just need the wizard or IQ add-on controller.
Get the model number.
pianotuna
Nomad III
Sep 09, 2014
Hi,

90% is not optimal, but run time from 90% to 100% will be as long as it is from 50% to 90%--say a total of 10 to 12 hours.

I would add a modest solar system and let the bank be fully charged each week while you are gone.

This kit looks pretty good: 200 watts including shipping
Yohyatt
Explorer
Sep 08, 2014
Thanks for all the replies.

To answer a few questions, I don't know what converter I have at the moment - will have to check next weekend.

I stay in my trailer most weekends as I'm getting ready to build a home and I should be getting power in 6 months, so i just need something to hold me over.

Someone mentioned charging just up to 90% on a genny - isn't that not optimal for the batteries? Thought you want to charge to 100%.

I spoke to my mechanic who installed the newer converter and he thinks it's at least a 40 amp converter, so maybe the batteries aren't getting enough volts? Doesn't seem clear to me that buying a 40 amp charger will solve my problem if my converter is a 40amp.

I know the best solution is to just buy a nicer covnerter, but those seem to be several hundred dollars and i can't afford to put that into my TT, so that's why i was thinking about a $70 charger.
hddecker
Explorer
Sep 08, 2014
RoyB wrote:
There really isn't anything magic about charging deep cycle batteries.

Here is what PROGRESSIVE DYNAMICS says about charging DEEP CYCLE MARINE TYPE batteries... We follow this guideline pretty close in our travels...

"Progressive Dynamics ran this test on the amount of time it took a PD9155 (55-amp) converter/charger set to three different output voltages to recharge a 125 AH (Amp Hour) battery after it was fully discharged to 10.5-volts.

14.4-VOLTS (Boost Mode) – Returned the battery to 90% of full charge in approximately 3-hours. The battery reached full charge in approximately 11 hours.

13.6-VOLTS (Normal Mode) – Required 40-hours to return the battery to 90% of full charge and 78-hours to reach full charge.

13.2-VOLTS (Storage Mode) – Required 60-hours to return the battery to 90% of full charge and 100-hours to reach full charge."

This is battery charging science at play here - not many ways to get around it

My PD9260C Smart Mode converter/charger will return my three 85AH Standard Issue GP24 Interstate 12VDC batteries to their 90% charge state in around three hours time. This happens when I am connected to SHORE POWER or running my trailer directly from my 2KW Generator using a RV30A-15A Adapter...

When my three batteries get hit with 14.4VDC Charging DC Voltage they will immediately start demanding around 53AMPS DC Current from PD9260C Smart Mode Converter/charger unit. This DC current starts dropping back in around 15 minutes as the batteries start taking on the charge and in an hours time is only drawing around 8AMP DC current while still being fed with 14.4VDC from the converter. After two hours of charging at 14.4VDC the smart mode converter/charger unit will drop down to 13.6VDC Charging mode with the DC Current now reading around 6AMPS DC. This mode will continue for another hour before attaining a 90% charge state for all three 12VDC batteries being charged together. The smart mode converter/charger may switch to 13.2VDC at this time if no load is being drawn from the battery bank. When a load is presented to the battery bank the PD9260C will autoswitch to 13.6VDC and remain at this level until the load goes away where it will again return to the 13.2VDC mode.

When the trailer load reduces the battery level to around 50% charge state then the PD9260C will go into its 14.4VDC boost charge mode again and will bring the battery bank to its 90% charge state in about three hours time.

This is the cycle process for my battery bank charging process using my PD9260C 60AMP Smart Mode charger.

If your charging system never hits the 14.4VDC mode then it will take many hours to attain a 90% charge mode status as indicated in the above Progressive Dynamics stated process. Most folks think you can force many AMPS into the charging process to make batteries charge faster. I have found this to be a 'NOT TRUE' assumption. You could have a 100AMP or even a 200AMP Source of 14.4VDC Charging Voltage and each 12VDC battery will only draw 17-20AMPS of this available 100AMPS charge source while being charged. The only way to charge quicker is to raise the charging DC Voltage. The down side of doing this is the battery will develop more heat in the process and will immediately start boiling your battery fluids. This could become very unstable and could end up in the battery actually exploding on you. The BATTERY FOLKS have determined the safe charging technique is to use around 14.4VDC to charge your 12VDC Battery and this process will take around three hours time to attain a 90% charge state.

I am NO BATTERY EXPERT just what I read about from folks like PROGRESSIVE DYNAMICS and TROJAN and also from my experience of charging my battery banks over the past few years.

Back in the 50s the local garage would advertise a quick one hour charge as the best way to get your battery charged. They would hit the 12VDC START BATTERY with around 50VOLTS DC (or more) with around 150AMPS available DC Current. The battery would almost turn "red" on you while being charged. Batteries would also explode on you. I witnessed one blowing its top which went into the air a good 50-feet or so at a local garage doing this. Glad I wasn't leaning over the battery when it happened...

Just saying....
Roy Ken

For sure you don't want to be leaning over a battery when it's charging. I damn near lost an eye way back when I was a pump jockey at a gas station. We had a battery on the charger, I went to check how it was doing and just as I got to the battery the hydrogen went KABOOM.

I never have been a fan of the quick charge, I never use the 60A setting on my charger and rarely use the 30<>10A, mostly just use the 2A. Takes longer but your not give the battery that big jolt that can over heat it.
pianotuna
Nomad III
Sep 08, 2014
Hi,

Are you full time or just boondocking?

How many watts is the generator?

Add a forty amp battery charger.

Consider upgrading the converter.

It really should not take 7 hours to get a pair of group 24 batteries charged. Most folks settle for 90% of fully charged when a generator is being used. It takes far to many hours of run time to get from 90 to 100%.

For generator charging, a higher voltage is preferred as it will fill up the battery bank sooner. I'd look at 15.4 as a good charging voltage.

Yohyatt wrote:
It takes about 5-7 hours to get my batteries from 12.1 (not connected ) 12.8 (soon as I connect) to 13.3, so I'd like to get a stand a lone battery charger to hookup from the genset to batteries.
time2roll
Nomad
Sep 08, 2014
Yohyatt wrote:
My question is - if i want to use 12v DC power while charging my batteries, can I plug in the shore cord and battery charger at same time to basically do the same thing that I'm doing when I plug the shore cord (I don't have an inverter/converter, just basic converter) with just a 2k genny?

Also how do I charge both batteries at same time with one battery charger, and additionally the shore cord plugged in. I know I have 2 outlets on genny -1 for shore and 1 for battery charger, but does the charger allow charging of 2 batteries. If my batteries are wired in parallel, would I be able to just hook up to one?

Yes you can use both the converter and a portable charger at the same time. I would start the portable first then plug in the RV main cord. Otherwise NO issues, no need to disconnect anything. Just slap that portable on direct.

Yes leave the batteries in parallel. The RV system and the portable will charge both together best.

Continue charging for at least one hour after voltage reaches 14.4 volts. I hope that portable is at least 10 amps.... 40 amps would be best.

Even better is to replace the converter as described above.

Forum Discussion

Battery charging process with EU2000i and poor converter?

About Travel Trailer Group

Related Content

Chassis battery won’t charge from converter

Battery charging

Battery charging

battery charging

Battery charge versus remaining usable charge