Using battery charger WHEN generator is running??

99dart · 06-16-2017, 03:36 PM

Could a person use a battery charger to charge the coach batteries at the same you have the generator on to charge the same batteries?? I know the coach charger will taper off as the charge comes up on the batteries as will the external charger I would hook up. Would that be pumping too much power in?

JamieGeek · 06-16-2017, 03:52 PM

It would more likely ruin one or both chargers as they fight to regulate their output voltage.

iDrive55 · 06-16-2017, 04:00 PM

Agree with JamieGeek, use only one charging system at a time. BTW, if you are able to connect to shore power, your battery will automatically be charged by the on-board inverter.

Harry B · 06-16-2017, 06:40 PM

Attaching an external charger will not help any at all. Your onboard charger will more likely provide more power than your external charger and as such render it useless.
When driving and running your generator at the same time, you have dual charging sources as well (converter & alternator)I and doesn't hurt anything

Chance · 06-16-2017, 08:05 PM

Quote:

Originally Posted by 99dart

Could a person use a battery charger to charge the coach batteries at the same you have the generator on to charge the same batteries?? I know the coach charger will taper off as the charge comes up on the batteries as will the external charger I would hook up. Would that be pumping too much power in?

My 2 cents ....

Batteries can only receive current at a certain rate given their size, condition, state of charge, etc.

I would suggest that installing a higher-capacity converter is better if your goal is to recharge batteries quicker, but even that may not help unless your existing converter isn't large enough for your batteries.

For example, if your batteries will only accept 30 Amps at correct charging voltage, and your converter could do 60 Amps, then there is little you could do anyway to charge batteries faster.

99dart · 06-17-2017, 04:31 AM

Thanks for the replies. It was just a thought I had and wanted to get some feedback. Thanks guys

iDrive55 · 06-20-2017, 07:59 AM

Does anyone know if the chassis battery as well as the house battery are charged when connected to shore power?

gmc · 06-20-2017, 11:45 AM

Quote:

Originally Posted by iDrive55

Does anyone know if the chassis battery as well as the house battery are charged when connected to shore power?

They are SUPPOSED to... Some have indicated it doesn't... Mine does.

There is either a battery control center or BIRD/Trombetta that controls the connection/isolation of the coach and chassis batteries and should include connecting them while on shore power to charge.

A good description of the systems are in Ed's Axis/Vega manual - a sticky on the forum.

Oneilkeys · 06-20-2017, 12:21 PM

Quote:

Originally Posted by iDrive55

Does anyone know if the chassis battery as well as the house battery are charged when connected to shore power?

It's easy to check and as if yours does. Plug into shore power wait a minute and put a meter on your starting battery. If it is charging it will read over 13.5v. If it does not, come back and I will help you find the thread that discusses this.

iDrive55 · 06-20-2017, 12:59 PM

Quote:

Originally Posted by Oneilkeys

It's easy to check and as if yours does. Plug into shore power wait a minute and put a meter on your starting battery. If it is charging it will read over 13.5v. If it does not, come back and I will help you find the thread that discusses this.

Thanks Oneilkeys. I was just thinking of doing that. I will let you know what I find.

99dart · 06-20-2017, 01:57 PM

Quote:

Originally Posted by iDrive55

Does anyone know if the chassis battery as well as the house battery are charged when connected to shore power?

I know our old 98 didn't charge the engine start battery. But, you pose a good question, I should put a meter on the WS31 as well when plugging in. I'm sure it would be hard to observe now, it has been plugged in for days.

Oneilkeys · 06-20-2017, 04:06 PM

Quote:

Originally Posted by 99dart

I know our old 98 didn't charge the engine start battery. But, you pose a good question, I should put a meter on the WS31 as well when plugging in. I'm sure it would be hard to observe now, it has been plugged in for days.

I believe all the recent Thors are designed to charge both the house and starting batteries simultaneously whether on shore power, generator or engine alternator. That does not mean that they all do (my Axis did not when I purchased it) but they should.

Metalman · 07-08-2017, 02:05 AM

Our Thor charges the chassis battery when plugged into shore power and when using the generator. Our last motor home, a diesel pusher, did not charge the chassis batteries, so I made a jumper to connect the + from the coach to the chassis batteries to keep them all charged.

DonKarstedt · 07-10-2017, 02:40 PM

Follow up question: How do you test it?

My house batteries just died and I'd like to test my charging system. How much charging current should be going to the batteries if everything is working properly? (I'm assuming it would be the same whether on shore power, engine power, or generator power?)

Oneilkeys · 07-10-2017, 03:25 PM

Quote:

Originally Posted by DonKarstedt

Follow up question: How do you test it?

My house batteries just died and I'd like to test my charging system. How much charging current should be going to the batteries if everything is working properly? (I'm assuming it would be the same whether on shore power, engine power, or generator power?)

If one or more batteries are discharged, while the system is being charged, the voltage at the batteries should read from 13.5-14.1v. The higher number if the batteries are way down. After the batteries are fully charged, if your converter charger is working correctly, the voltage should drop to 13.1v which is a trickle charge to keep your batteries fully charged and not boil over the batteries.
The Thor coaches are different in many respects so it helps if you list your coach in your profile. That way you have a better chance of getting info spefically for your coach.

Oneilkeys · 07-10-2017, 03:31 PM

Quote:

Originally Posted by Oneilkeys

If one or more batteries are discharged, while the system is being charged, the voltage at the batteries should read from 13.5-14.1v. The higher number if the batteries are way down. After the batteries are fully charged, if your converter charger is working correctly, the voltage should drop to 13.1v which is a trickle charge to keep your batteries fully charged and not boil over the batteries.

You can test the voltage at the batteries posts or - if your have a Trombetta - at either post of the Trombetta (red wire to one Trombetta post and black grounded to the chassis - an unpainted bolt works.) The voltage at both battery banks (chassis and house) should read approximately the same when the system is charging. Wait a couple of minutes after turning in the charging system (shore power, generator or engine alternator) to allow the Trombetta or battery control center to open so that both systems are being charged.

DonKarstedt · 07-10-2017, 04:06 PM

Can I infer from what you are saying that the charging system will output nothing, if the batteries are completely disconnected and removed?

Ideally I would like to test the output of the charging system without the batteries being connected, but it's sounding like if the system doesn't sense there is a load, it may not send out charging current? Is that correct?

Oneilkeys · 07-10-2017, 04:31 PM

Quote:

Originally Posted by DonKarstedt

Can I infer from what you are saying that the charging system will output nothing, if the batteries are completely disconnected and removed?

Ideally I would like to test the output of the charging system without the batteries being connected, but it's sounding like if the system doesn't sense there is a load, it may not send out charging current? Is that correct?

No. If you take out the batteries and turn on the generator or plug into shore power, the system will still put out a charging current through the charging line to the house batteries. It's not really a good idea to do this because if the positive wire hits anywhere on the chassis it will energize the chassis and probably melt whatever it touches - including you. Since the BIRD or BCC will not sense a charge on the battery, it will not open the Trombetta so no current will flow from the converter/charger to the chassis battery - or if the chassis battery is disconnected - to the chassis battery line.

Better idea to reconnect one house and chassis battery and test the charging system. That is the only way to check if the generator/shore power is also charging the chassis battery (as it should) or if the engine alternator is also charging the house batteries (as it should). It's also a lot safer.

DonKarstedt · 07-10-2017, 04:53 PM

That's good advice, thank you. I'm on my way to buy new house batteries right now, so I will wait until I have them connected before testing.

DonKarstedt · 07-10-2017, 10:45 PM

So I have my new house batteries, and they measure 12.61 volts without being connected to the house. After connection, the voltage measured at the battery terminals drops to 12.53 volts. I've checked it a few times over the past hour and the voltage still sits at 12.53. Do you think my charger is not charging, or does the battery voltage have to drop further before the charging current kicks on? (I'm connected to shore power)

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