Dead batteries

[Odetymes]

2019 Ventana
After an electrical storm and being out of town I returned to find both coach and engine batteries totally dead due to a power failure at the facility. With power back on and the on board trickle charge on (shows on 3 amps charging?), I also attached a separate trickle charge to the engine batteries at a 15 amp quick charge (too fast?). I managed to blow the quick charger (now deceased), and finding the coach batteries haven't charged at all even though the power is on and they are brand new (all 8). Any suggestions as to what I'm doing wrong? Can't call Newmar due to weekend. I'll call auto club tomorrow for start the engine, then turn on the generator.

The screen for inverter status has a green light blinking and it does say it's charging but doesn't seem to move off the 3 amps. Suggestions as to a remedy are most appreciated! Thanks!

 

[Chuggs]

The Inverter is designed to protect itself and your coach by NOT connecting to a voltage that would be indicative of a shorted or dead cell...

You will need to attach a charger to the bank...and allow the voltage to get back to a nominal voltage...and reattempt restarting the Coach charger.

Your coach probably has a 240A alternator...so, NO --- 15A isn't too much.
And as far as the House batteries...if they are Interstate Lead Acid.. they take a charge rate of C/10. IDK your ratings...but if you had 840aH bank...that would be 84A. Of course the Magnum you have only lets you set a percentage of the 125A rating of the charger. Which Newmar seems to leave at the default rate of 80%. 80% of 125 = 100A. Trojan recommended C/5. Most AGM's can handle more...

Watch your water levels on flooded batteries... going from Zero to Hero is gonna have a pretty lengthy BULK charge going on... many batteries never regain the capacity back after being discharged that deeply. Especially, if they sat for a while like that.

Once both batteries get above 12v...you're house battery charger will be back to charging both sets thru the bi-directional relay...and you can dispense with the supplemental battery chargers.

If your unit has wifi...you might want to add a system to alert you of low voltage. A text, telling you that the voltage has dropped...would give you an opportunity to intervene...possibly go over and run the generator for a bit to keep things charged...while power availability gets sorted.

 

[Odetymes]

The Inverter is designed to protect itself and your coach by NOT connecting to a voltage that would be indicative of a shorted or dead cell...

You will need to attach a charger to the bank...and allow the voltage to get back to a nominal voltage...and reattempt restarting the Coach charger.

Your coach probably has a 240A alternator...so, NO --- 15A isn't too much.
And as far as the House batteries...if they are Interstate Lead Acid.. they take a charge rate of C/10. IDK your ratings...but if you had 840aH bank...that would be 84A. Of course the Magnum you have only lets you set a percentage of the 125A rating of the charger. Which Newmar seems to leave at the default rate of 80%. 80% of 125 = 100A. Trojan recommended C/5. Most AGM's can handle more...

Watch your water levels on flooded batteries... going from Zero to Hero is gonna have a pretty lengthy BULK charge going on... many batteries never regain the capacity back after being discharged that deeply. Especially, if they sat for a while like that.

Once both batteries get above 12v...you're house battery charger will be back to charging both sets thru the bi-directional relay...and you can dispense with the supplemental battery chargers.

If your unit has wifi...you might want to add a system to alert you of low voltage. A text, telling you that the voltage has dropped...would give you an opportunity to intervene...possibly go over and run the generator for a bit to keep things charged...while power availability gets sorted.

You information is most appreciated and yesterday I put a trickle charge on the coach batteries hoping they are up to speed this morning. I will attempt a start and get the generator going. I will also attach the trickle charge to the house batteries and try to bring them up. Hopefully there is no damage as the batteries were put into service only a month ago (all eight).

If no success this morning I"ll call the auto club for a start and from there. Again, thanks!

 

[Chuggs]

You information is most appreciated and yesterday I put a trickle charge on the coach batteries hoping they are up to speed this morning. I will attempt a start and get the generator going. I will also attach the trickle charge to the house batteries and try to bring them up. Hopefully there is no damage as the batteries were put into service only a month ago (all eight).

If no success this morning I"ll call the auto club for a start and from there. Again, thanks!

You may need a full blown vehicle charger... sone "trickle chargers" wouldn't pump out much.

I haven't tried this... butbif you can start your coach, or start your coach with a jump. Let it run...and check the voktage on the chassis on your digi-level display. When it gets up around 13+ volts...keep watching your digi-level while an assistant holds the BOOST switch down on your dash. This should override your bi-directional relay closed. Have them keep holding while you carefully check for rising voltage on the house side on the digi-level guage. When it comes up to 12.0 v....try to momentary press the CHG soft key on the Magnum Display. Look for a status line change to "Bulk Charging"... if that works...have your assistant let go of the boost button. I wouldn't have them hold it too awfully long...so, really prefer an external dumb charger to bring the bank up...but this might work. Remember...your bi-directional relay is probably rated for 225A...but there is 40ft of 2/0 wire between the chassis and the house bank with zero circuit protection (not current limited by a catastrophic fuse).

Hope it works.

If you have flooded lead acid batteries... you migjt co sider doing an equalization charge. This is a higher voltage charge that will help drive additional sulphate deposits fron the plates. Most AGM batteries do not recommend this, as it may cause the case to vent...and you habe no way of adding water. So, check for mfg. recommendations for your specific battery.