Batteries On the 1996 U 295C takes a long time to charge . I had run our generator three days in a row for four hours at a time and I'm still not up to zero amp hours on the meter. It doesn't seem to be charging very much as we are going down the road either.
What charger or inverter charger do you have?
Does it have a remote panel? If so, what are charging amps and at what voltage?
What kind of batteries (wet cell, AGM, gel, LI) and what is their condition?
Basically, we need more information to be of assistance.
Bret, we have a Power TECH 10,000 W generator, then there's a magnum charger inverter, and we have the remote for the magnum up in the coach. Then there is a cruising equipment amp Hour meter. The batteries are brand new about 2 1/2 weeks ago. Unfortunately I couldn't get lifeline batteries, Had to settle for interstate 8B8D AMG batteries. The meter reads when it is Bulk charging 14.2 V and 83 Amps.. then it drops down to absorb charging 14.4 volts and 20 or less amps. When driving down the road should that be charging the coach batteries from the alternator?
YES, both battery banks (chassis and house) should be charged by the alternator while driving.
And, you charger amps and voltages are right inline.
What is the voltage coming from your alternator.
The shut off may be 14.2 or so. tTthe charging systems will stop any electron flow. Very low or no amps may show.
Turn everything on and watch the amps.
Okay, we need to apply a little knowledge and a little logic here.
The three voltages and the names that apply o them are;
3) 14.4 VDC Bulk. This is rapid charging up to about 80% battery capacity.
2) 13.6 VDC Absorption. This goes on for another 24 hours or so and brings the battery from 80% to 100% state of charge.
1) 13.2 VDC Float. This is just enough voltage to counter the inherent self discharging of a lead acid battery without adding to
the state of charge.
If you are reading 14.2V @83A then your charger is rolling back the voltage to keep it from trying to supply more amperage than it is capable of doing. You should start timing your charge cycle from the point when the charging voltage reaches 14.4V. No more than another 4 hours at that voltage. The charging current will continue to fall.
And none of this is cast in stone. But if you need electrons it's best to start with a known quantity. If you can manage 3-days on shore power, and after 3-days of charging, Zero your Wattage totalizer. They do drift over time and to use a technical term, the gazintas don't always equal the gozoutas.
OP,
ASSUME your inverter/charger is properly programmed for: battery chemistry, battery size (amp-hours) and temperature (or remote temperature probe).
Most smart chargers (or inverter/chargers) keep the same voltage for bulk and absorption, but dial back amps in absorption. Then in float, voltage is reduced.
You may never get to zero amp-hours. Everything is approximate. And the meter may or may not correctly compensate for the fact it takes more amps to charge back what has been discharged. And you will find that batteries will continue to accept less amps as it gets 'fuller', so the first half may take a couple hours and the next up to 80% longer and to get from 80% to near 100% up to a couple of days. That is why it does not pay to run a generator that can power a 100-amp charger, when the battery only accepts a few amps. Lot to learn about batteries. Nothing linear about them.
Some add solar to 'finish' off batteries as they put out fewer amps more in line with how batteries accept the last few amps.
Battery charger / alternator control charge voltage. Batteries control charge amperage accepted. Higher voltage will increase amps at the cost of overheating battery and potentially causing problems with sealed batteries or evaporating electrolyte in fillable wet cells.
Older batteries act differently.
If running the generator to charge the batteries, the most fuel efficient way (and best for battery life) is:
Discharge to 50% SOC.
Charge to 85%
Discharge to 50%
Repeat. But, once a week bring them to 100% SOC.
We did this month after month when anchored out in the sailboat in the Bahamas.
The other way to tell is when amp- charge rate drops off. Makes sense to run the generator when charge rate is 85 amps. Not so much when it is down to 30.
If dry camping with a buddy, "buddy charge". Alternate running your generator and theirs. On the coach not running the generator, turn off every 120 VAC appliance/breaker except for the charger or inverter charger. Plug that coach's shore power cord (using adapters) to the other coach. We did this often when camping in Mexico.
Constant current is one of the charging strategies, constant voltage is the other. The Progressive Dynamics line is in the latter category and I believe it achieves the shortest charge time albeit at the risk of battery damage if the PD unit provides too much current for the battery size. Conservative current is estimated at 1/10, one-tenth, 10% of battery capacity. The Original Poster's report of a 14.2V Bulk and 14.4 Absorption leads me to think that his charger is in the latter category, constant voltage.
Either way a battery use totalizer still needs to be zereoed out from time to time to be of good use.
Common charging algorithm is for voltage to remain constant during Bulk and Absorption and then drop when in Float.
But, this varies by make and model of the charging device.
To everyone: Make sure your smart charger is PROGRAMMED PROPERLY. That is the only way it can be "smart". Common issues are battery technology, battery bank size and temperature (if not remove temp probe).
I have everything turned off with the switch by the staircase. Why is it still draining my batteries? I realize there's some minor drainage, but it will have 50 Amps overnight.
Possible faulty charger . Disconnec t the charger and test for draw on the charge cable. Disconnect the battery's and let sit. Watch the voltage drop.
Mike Ogren is being nice.
If you disconnect the batteries and the voltage, as measured after the first 3 hours is lower at the end of 24 hours then your batteries have reached the end of their service life. The plate material has built up to a level in the bottom of the battery case to where it has reached the bottoms of the plates and is shorting them together.
Can I charge the batteries by a battery charger plugged into a separate 110 V Source?
Linda & Randy,
About half of the circuit breakers in 12v bay wall streetside panel is still live when salesman switch is turned off. Check you wiring diagrams. Refrigerator is possible the drain even with stairwell salesman switch off.
Inverter and other things are not under control of the salesman switch.
Yes, but.
1 Ampere for 1 Hour is 1 AmpHour. But the battery holds onto only about 65% of that so it's really 0.65 AmpHour.