House Batteries

[homelesshartshorns]

I understand the idea of house batteries simply charging only to 13.6 on the Generator through the inverter. And I understand that they charge up to 14. on the alternator. So is the alternator hurting my batterys charging at such a high state? 

If not how can I charge my batterys at the highest state with only the generator? Im not sure I understand my question, I hope some of you do????

[Chad Heiser]

First, what type of batteries do you have?

Most batteries bulk charge in the 14 volt range without issue.  It really is dependent on what your battery manufacturer recommends though.  
 

The charging voltage going to your batteries while the generator is running is coming from your converter (or inverter/charger if you have one).  If the device is programmable then you can manually set the charge level by changing the programming.  Not all chargers are programmable though.  Some have preset charge algorithms that can be selected.  If this is the case, there may be a different algorithm you could select.  If you don’t have either of these options, then the only way to up your charging voltage is to replace your existing charger (either converter or inverter/charger) with a new one that charges at the proper voltage or is programmable so you can set the desired voltage.

Another option is to add a standalone battery charger that charges at the desired voltage when it is plugged in and receiving power from the generator or shore power.

[oldjohnt]

15 hours ago, homelesshartshorns said:

I understand the idea of house batteries simply charging only to 13.6 on the Generator through the inverter. And I understand that they charge up to 14. on the alternator. So is the alternator hurting my batterys charging at such a high state? 

If not how can I charge my batterys at the highest state with only the generator? Im not sure I understand my question, I hope some of you do????

 Great advice from Chad above !!!!!!!!!!! Good morning Sir, good questions, here's my response: NOTE: When you say through the Inverter, Im thinking you mean through the charger??????? Or do you have a Combination Inverter/Charger??

 1) When you say "house batteries simply charging only to 13.6 on the Generator through the inverter" HOW DO YOU KNOW THAT TO BE THE CASE?? Typically the genset or shore power runs a Converter/Charger or a Combination Inverter/Charger (whichever you have) AND THE VOLTAGE AT WHICH THEY CHARGE DEPENDS ON THEIR DESIGN AND ANY PROGRAMMABLE OPTIONS. Iffffffffff its a so called Smart 3 Stage Charger for charging lead acid batteries, it may Bulk Charge at 14+ or so volts, Absorption charge at maybe 13.6 or so volts, Float charge at maybe 13.2 or so volts. THE ANSWER DEPENDS ON YOUR CHARGER DESIGN AND SPECS AND YOUR BATTERIES I have no idea what you have. If you have an older buzz box more like a constant voltage charger (perhaps constant 13+) they may given enough time possibly overcharge but that's older technology and again depends on the charger and your batteries.  

2) You ask "And I understand that they charge up to 14. on the alternator. So is the alternator hurting my batterys charging at such a high state?  SHORT ANSWER PROBABLY NOT (absent detailed info and battery specs I just cant say for sure)  

    Typically an alternator may indeed charge around 14 Volts. HOWEVER is your alternator connected (perhaps via a solid state dual battery isolator or a solenoid arrangement) so it charges your house batteries as well ?????? SOME ARE SOME ARE NOT. That being asked and said, the Engine and House batteries SHOULD BE THE SAME TYPE AND CHEMISTRY and ifffffffffff you're wired such that when driving the alternator is also providing charge to your house batteries ??? the chances of damaging your house batteries from overcharging may be minimal, BUT IT DEPENDS ON THE WIRING, LINE VOLTAGE DROP, AND ALTERNATORS VOLTAGE REGULATION PLUS YOUR HOUSE BATTERIES. Ive owned several RV's in which case when driving the alternator charged BOTH engine and house batteries BUT ALL WERE WET FLODED LEAD ACID I never had any overcharging problems due to line voltage drop and other losses. BUT I CANT SAY NOT KNOWING YOUR BATTERIES AND WIRING. Id take a PURE GUESS the chances of overcharging via the alternator (due to wiring, line voltage drop and loses) are MUCH MUCH LESS (maybe even never) than overcharging via the Charger, but I dont know your charger specs HARD TO SAY HERE IN THE DARK     

 One more recent and modern method to provide a more correct charge using the alternator to charge house batteries (Proper programmable charging not overcharge) is to use a DC TO DC CHARGER. That way your alternator isnt over worked plus your batteries can be correctly charged.  

NOTES: 1) If you don't already have one I suggest upgrading to a so called SMART Regulated 3/4 Stage Charger (matched for YOUR batteries) so shore or generator power correctly charges your house batteries... 2) If you have a solid state dual battery isolator or some sort of a solenoid configuration so when driving your alternator charges BOTH engine and house batteries, I WOULD WANT ALL TO BE THE SAME CHEMISTRY (DO NOT to mix lead acid and lithium !!). That method has been used usually okay without overcharging (I did it often back in the day NEVER overcharged) house batteries BUT IT DEPENDS ON WIRING, BATTERIES AND ALTERNATOR. 

 If you knew your chargers specs and design,,,,,,,,your battery details,,,,,,,your configuration for connecting engine and house batteries,,,,,,,,,I may be able to provide more accurate info, so for now only take the above with a grain of salt and consider it as a start and basic education, NOT final advice.

 

 John T Best I have to offer based on such limited information  

       

  

Edited October 4, 2022 by oldjohnt

[homelesshartshorns]

You seem to know the topic and are a very skilled with the English language. But I am not, Im not really sure what the question is! But I find when running down the road for a few hours my house batteries will take care of my needs for an afternoon and over night with out falling much below 12.1 but after a week of boondocking I find charging with the generator does not bring up the batteries like the first day. And infact each day seems to make them even less effictive. I would like to know how to bring up the house batteries with out using the alternator? Or if this is even possiable. 

[Jaydrvr]

1 hour ago, homelesshartshorns said:

You seem to know the topic and are a very skilled with the English language. But I am not, Im not really sure what the question is! But I find when running down the road for a few hours my house batteries will take care of my needs for an afternoon and over night with out falling much below 12.1 but after a week of boondocking I find charging with the generator does not bring up the batteries like the first day. And infact each day seems to make them even less effictive. I would like to know how to bring up the house batteries with out using the alternator? Or if this is even possiable. 

If your inverter has a smart charger, it'll fill with bulk charging for most of the battery capacity, then switch to absorption to finish filling the battery. However, it takes a long time to top off a lead acid battery, but it's quite important to do that regularly. Not fully topping off your lead acid batteries will reduce the total capacity available and shorten their life. It makes a good case for switching to lithium, which is actually happier not being topped off. Jay

P.S. I get the impression you don't have a state of charge monitor. That would be a valuable addition to your system, as then you would be able to see exactly what is going on and how much your batteries are actually getting charged.

Edited October 4, 2022 by Jaydrvr

[oldjohnt]

1 hour ago, homelesshartshorns said:

But I find when running down the road for a few hours my house batteries will take care of my needs for an afternoon and over night with out falling much below 12.1 but after a week of boondocking I find charging with the generator does not bring up the batteries like the first day.

Thanks for the feedback, here's my response: YES its possible and common when dry camping to use the generator to power your Converter/Charger to charge the batteries. YES as you already know the alternator (if wired and correctly configured) can help charge house batteries when driving. 

 From what you say it appears when driving you're wired and configured such that your alternator is charging your house batteries to some extent at least (NOT overcharged maybe or maybe not fully charged)  ALLS WELL SO FAR and if it aint broke don't fix it...

 If charging via generator or shore power and your Converter/Charger isn't adequate that's not all that surprising and may be caused by:

 1) Your Converter/Charger isn't rated very high (or poor quality or not working right or miswired), maybe its only 20 or 30 amps max ??????

 2)  Your batteries may have some issues, had them checked and load tested recently??? Also they should be true Deep Cycle NOT starting batteries.... 

 3) You may not have adequate Amp Hours of battery energy storage. 

 If all is working otherwise and your batteries are basically okay but you want faster charging YOU MAY JUST NEED A HIGHER RATED CHARGER. See what yours is rated for and if only say 20 or 30 Amps a 40 to 60 will charge faster. I suggest a Smart 3/4 Stage Regulated unit suitable for and matched (or programmable) for your batteries. I also strongly suggest you invest in a quality Shunt Based battery monitor to see the actual condition of your batteries and how many charging amps in or discharging amps are flowing out...

NOTE its best to NOT discharge lead acid batteries over 50% of their rating !!!!!!!! FYI  a fully charged lead acid battery at rest and stabilized at 67 Degrees would read 12.61 Volts while 11.98 Volts indicates 50% discharge....... 

 Take a look at your Converter/Charger to determine its rating and specs,,,,,,,If a charger is working ??? when on battery voltage should rise to at least 13 and up to 14 or so subject to charger and batteries,,,,,,,,,Determine your battery type and rating and if necessary have them tested.......

 Best I have to offer for now

John T   BSEE,JD  50 year RV owner   

      

 

[homelesshartshorns]

13 minutes ago, oldjohnt said:

Thanks for the feedback, here's my response: YES its possible and common when dry camping to use the generator to power your Converter/Charger to charge the batteries. YES as you already know the alternator (if wired and correctly configured) can help charge house batteries when driving. 

 From what you say it appears when driving you're wired and configured such that your alternator is charging your house batteries to some extent at least (NOT overcharged maybe or maybe not fully charged)  ALLS WELL SO FAR and if it aint broke don't fix it...

 If charging via generator or shore power and your Converter/Charger isn't adequate that's not all that surprising and may be caused by:

 1) Your Converter/Charger isn't rated very high (or poor quality or not working right or miswired), maybe its only 20 or 30 amps max ??????

 2)  Your batteries may have some issues, had them checked and load tested recently??? Also they should be true Deep Cycle NOT starting batteries.... 

 3) You may not have adequate Amp Hours of battery energy storage. 

 If all is working otherwise and your batteries are basically okay but you want faster charging YOU MAY JUST NEED A HIGHER RATED CHARGER. See what yours is rated for and if only say 20 or 30 Amps a 40 to 60 will charge faster. I suggest a Smart 3/4 Stage Regulated unit suitable for and matched (or programmable) for your batteries. I also strongly suggest you invest in a quality Shunt Based battery monitor to see the actual condition of your batteries and how many charging amps in or discharging amps are flowing out...

NOTE its best to NOT discharge lead acid batteries over 50% of their rating !!!!!!!! FYI  a fully charged lead acid battery at rest and stabilized at 67 Degrees would read 12.61 Volts while 11.98 Volts indicates 50% discharge....... 

 Take a look at your Converter/Charger to determine its rating and specs,,,,,,,If a charger is working ??? when on battery voltage should rise to at least 13 and up to 14 or so subject to charger and batteries,,,,,,,,,Determine your battery type and rating and if necessary have them tested.......

 Best I have to offer for now

John T   BSEE,JD  50 year RV owner   

      

 

Thank you, I will look into your suggestions. 

[Ray,IN]

It would really help to know the make and model number of your inverter/charger.

[homelesshartshorns]

18 minutes ago, Ray,IN said:

It would really help to know the make and model number of your inverter/charger.

I dont know what it looks like or where it is! Judging by a Watt Out meeter in the hall way, Im guessing it puts out 4 watts!

Edited October 5, 2022 by homelesshartshorns

[Ray,IN]

George that sounds like describing a solar output meter. The inverter/charger display itself will only show battery charger output, which is measured in amperes instead of watts. It should appear similar to this picture if it has a built-in battery charger

Edited October 6, 2022 by Ray,IN

[oldjohnt]

17 hours ago, homelesshartshorns said:

I dont know what it looks like or where it is! Judging by a Watt Out meeter in the hall way, Im guessing it puts out 4 watts!

Some (Converter/Chargers) are a part of (located behind) the assembly where you find your DC fuses and AC circuit breakers. Other Chargers may be stand alone units with 120 VAC input and Battery charging volage on output. They are much more than 4 watts, Id pure guess maybe a 20 or 30 Amp charger, likely NOT a Smart Multi State Regulated, they can take a relative LONG time to charge a very big or very discharged battery bank, but hey they get the job done for low energy users who don't dry camp often.

 Not sure what that Watt Out Meter is for, 4 watts isn't much, what other equipment or accessories does the RV have ???????

 Best I have to offer based on little information

John T