[Greg]

Dale,

Lifelines take is the AGM’s can use the wet cell settings if AGM is not an option on an inverter/charger. Usually, an alternator will be in the high 13’s when driving, not much more than a float charge. So if your alternator is charging the house around 13.8, no problem.

[Georges]

What I recall, the inverter starts at 14.2 and ends up at 13.8, just a good guess.

Just seems to me that after a night of inverter charge the batteries last longer then a day of driving, just a good guess.

[Archived]

Some regulators are adjustable. My house batteries were just changed and the regulator was lowered to 13.6, its lowest setting. Keep in mind that your inverters are working when on engine power,or are likely working at least. Given the increased 12 volt loads, the higher voltage should not be a concern, as long as you’re within the battery’ specs. Lifeline’s specs are 13.1 – 13.4 for float and 14.2 – 14.6 for charge.

Gil

[Archived]

Dale, do you have a Delco 50DN alternator? A few us run Balmar 624’s to control the alternator current. I am running Deka AGM’s and I can adjust the voltage and profile for my dual Xantrex SW4024’s. I am upgrading to a 450 amp Niehoff C802. They were able to build me a custom regulator that would handle the high field current >20amps..

[Archived]

I think the answer to Dale’s question might be affected by how he uses his coach. If he dry camps and does not run the generator (thus charging the house via the inverters) but expects them to be charged properly via the engine when driving then the house is likely not getting the proper charge which really should start out with the bulk rate for the type battery, then absorpbtion rate for the battery type, and finally float.

Continued charging via the bus alternator is likely to not go through the proper three stage cycles. But if he charges the house via the inverters routinely it is probable if the bus alternator is set so it doesn’t exceed the battery float voltage the chances are nothing needs to be considered or done.

As long as we are on shore power or using our generators our house batteries are being well maintained and the charge they receive while we drive just keeps them topped off. The key to battery life is that when they are drawn down they need to be recharged using the inverters or a good three stage charger. And try to recharge them when they are at 50% or more charge rather than deeply discharging them to increase their number of life cycles.

[Dale]

I guess the main question I was trying to resolve is; can my house batteries be fully charged at the end of a 10-12 hour run down the highway? It just doesn’t seem as good of a charge as plugged in over night.

“I am upgrading to a 450 amp Niehoff C802” Does this have the ability to fully charge the house batteries in 10 hours or so?

[Kevin]

Dale,

I can watch my house charge and amps as I’m driving, usually around 13.7 or there abouts and after 4 or 5 hours, they’re topped off. Then hooking to shore power my intverter/charges go directly to float. I know there are a lot of variables to this, but 8 to 10 hours should have them fully charged.

[Ken]

Dale, the Niehoff will PACK all the amperage into the batteries better than inverters on shore power and/or genset rates. The nice thing about the Deka AGM’s is that you can charge them at a higher voltage than other AGM’s. AGM’s by nature will accept more amperage vs flooded cells. The standard Niehoff regulators have 3 alternate voltage settings HOWEVER, it does NOT have battery TEMP just Alternator Temp compensation. I did not want to cook my AGM’s.. Most of us are using inverted power while driving but I drive at night and I seen that my battery bank didn’t need alot of the amperage. So, I went searching to see if I could get a programmable smart regulator.

[Archived]

Here is a recent picture of my two alternators and Balmar Super Twenty Four multistage 24 volt regulator.

[Charles]

I’m not convinced a set of relatively discharged batteries are going to receive a proper charge from a conventional alternator / regulator set up. All battery charge specs that I have seen indicate they are to be charged using the three stage protocol which includes a bulk rate higher than the typical regulator voltage setting. Failure to fully charge a set of discharged batteries affects the battery life and I think Dale is absolutely correct in noting they do not seem to be as fully charged despite being charged via his alternator all day.

http://www.batterystuff.com/kb/articles/battery-articles/battery-basics.html#9

Under charging this link speaks briefly about the need for a three stage charge. I have seen other more technical explainations of charging but bottom line is batteries need proper charging at varying voltages.

[Ed]

Some more links on charging:

http://www.bdbatteries.com/mcharging_procedures.php

The Lifeline site is the pertinent poop direct from the manufacturer and is to be considered the best advice for their battery. Every manufacturer’s instructions should be considered the final word.

http://www.windsun.com/Batteries/Battery_FAQ.htm#Battery Charging

http://www.windsun.com/Batteries/Battery_FAQ.htm

The above site is an excellent one and has an abundance of information regarding batteries.

http://marine-electronics.net/techarticle/battery_faq/b_faq.htm

This is an excellent site for information. It has good information relative to all types of batteries (lead acid, gel and AGM)

[Thomas]

Jon, I agree with you 100%. The standard OEM regulators just aren’t up to the task to safely charge the house batteries. However, the smart regulators with multi programmable, multi stage charging modes are capable and have been doing this for many years. Marine sailing vessels and offshore boats have used these regulators for a few years.

Again most inverter chargers or smart battery chargers driven by shore power or genset power can only input a fraction of amperage back into the battery bank. My battery bank is close to 1000 amp hrs. I can use the 450 amps inrush to reduce the charge time. In the event that over the road demands wain, this regulator can safely put my batteries into a Float mode. This regulator has the ability to Equalize the batteries. Very few AGM have manufacture recommendations for this mode. Lifeline does allow it.

The Balmar Max Charge MC624 has the following options and charge modes..

Start delay up to 999 seconds

Compensation Limit 28 to 32 volts

Bulk Voltage 28 to 29.6 volts

Bulk Time from 6 mins to 6 hours

Absorbtion Voltage 27.8 to 29.4 volts

Absorption Time 6mins to 6 hours

Float Voltage 26 to 28 volts

Float Voltage Time 6 minutes to 12 HOURS…

Amp Manager >> This allows for precise reduction in maximum allowable field percentage, making it possible to reduce alternator horsepower load on drive belts. Or to provide governance to protect the alternator from abnormally larger battery or system electrical loads.

[Archived]

I think the bottom line for conversion owners is to first determine how they use their coach and batteries. Some dry camp a lot. Some (like me) will only be without AC imput when driving and go from shore power to shore power or run the generator. The type of use dictates how the batteries are going to be best maintained.

I am not aware of any factory or converter alternator systems using “smart” voltage regulators but in some cases that would be an excellent modification, especially for those coaches that are rarely on shore power and which rarely run the generators, relying on the engine driven alternator to maintain the house batteries.

[Larry & Diane]

Well guys, we do not know who converted Dale’s 86 XL and so we do not know anything about how the house battery system was designed. All coaches are not the same in this regard.

Jon, your experience seems to be with Liberty designs, I can say with great certainty that Marathon uses a very different approach. We have a 94 Marathon conversion. Six 8D house batteries ( 20 hour capacity is 6 x 255= 1530 amp hours), ONE alternator, a 50DN rated 270 amps at 28 volts. There are battery isolators and combiners that allow the one alternator to charge everything. That is 270 x 28 = 7560 watts.

1530 amp hours x 12.8 volts = 19,584 watt-hour capacity ( 19584/7560=2.59 hours). So I can fully charge the house bank in less than 3 hours driving down the road. And this is exactly what I have experienced many times. Of course the alternator is also charging the start bank and supplying power for all chassis and house loads while driving so it might take a little bit longer.

I have found charging while driving down the road to be quick, easy, thorough. While running on the generator or shore charging takes much longer, both ways use the inverters as chargers at a lower rate.

By the way, from the Lifeline website:

Rapid Recharge-

Lifeline Batteries facilitate a significant increase in recharge rate,
with amazingly high current limitations when you properly regulate the
charging voltage. Customers charge 100ah batteries with 500amp chargers
routinely.

[Archived]

My experience has been the same as Peter’s, the systems we have
work well.

As for Equalizing, it comes up all the time and while it won’t
hurt, it won’t do much good on AGM’s. I’ve had that discussion
numerous times over the years with Lifeline while I’ve been a dealer
and it’s OK if you want to do it, but you won’t get much in the way
of better performance or extended life out of your batteries. Try it,
I have on two occasions and didn’t gain anything. Usually Equalizing
comes up when the batteries are at the end of their life and folks
hope to delay the inevitable, me included.