LiFePO4 Batteries - First Experience

3/21/14

The batteries were left with the van sitting and not doing anything after the batteries were installed. I pulled the fuse on the CO and LP monitors because they are not working and beeping. After about 2.5 weeks, the battery monitor said they were at 12.5V and the next morning, they had shut down entirely. The Battery Management System (BMS) is supposed to do that with a bit of battery left. The volt meter showed zero volts, which it should in a shut down situation.

In the meantime, I noticed the shore power AC neutral (white) wire nut was charred and fused. Anytime I see that, it worries me so I replaced the shore power wire. Fortunately, Lowes has the 30amp 10 gauge outdoor wire with 3 leads so it was easy to get.

When I plugged in the shore power, the new charger blinked the 30% light and continued for several minutes. That means it can’t detect any power on the battery end or less than 2%. So I guess if the BMS goes to shutdown mode, the charger can’t get going. I attached my manual battery charger and plugged it in. I got an immediate loud noise and unplugged it. Not sure what that was about. But the charger started charging showing 10%light and the battery monitor showed 11.2V and rapidly rising. After about an hour the monitor says 12.5V. Since the 2 batteries are in a banks, it will take longer to charge them up than it did for a single battery.

It seemed to me that there were more amps being used than there should have been with nothing going on. I put the volt meter on my engine battery and it was fully charged so my guess is that my trick-l-charge device that shunts a little juice to top off the engine battery when plugged into shore power was using the LiFePO4 batteries to top off the AGM battery and thus used a lot more juice than it should have.

My brother thinks that the engine batteries are not healthy and that they are needing more topping off than they should. I have had incidences of them not having enuf juice to start the engine. He thinks that is evidence of them failing. I’ve been thinking they need to be tested and might be the same age as the house AGMs and are not in good shape.

SprinterFest East is scheduled for May 3^rd so I am going to try to have a little session with the repair shop to replace my serpentine belt and check and possibly replace the battery. Everyone says the Sun shop in Harrisburg is the best of the best, or at least right up at the top of the quality.

Charging time on a 15 amp circuit:

11.2V 10% as it came on

12.5V 10% +1 hr

12.9V 30% +2 hrs

13.0V 30% +3 hrs

13.2V 30% +7.5 hrs

Next morning:

13.3V 30% 3 lights flashing indicating more than 16 hours of charge time when it automatically shuts off.

Unplugged shore power and plugged it back in to restart the charge cycle:

13.3V 30% as it came on

13.4V 50% +:15 mins

13.4V 50% +:1 hr

13.5V 50% +:3 hrs

13.6V 50% +:7 hrs

Restart the cycle: 11:30p

13.6 in the am with green light indicating the charger is shut off and the batteries are fully charged

I tried starting my generator without success. That burned the batteries down to 13.4V. I plugged the charger back in after finishing the tidying for the new shore power cord – cable tie the wires, screw down the wire boxes. This time it didn’t take long for the batteries to get back to fully charged:

Started at

13.4V 30%

14.4V 90%

15.6V 90% blinking as it finished up

14.4V after it finished with the green light

13.6V after about an hour later

After a week with the Trik-L-Charge disconnected, The batteries showed 13.3V and the AH used were about 50. That included having the ceiling fan on full speed all night accidently. The new charger does not trickle charger the batteries but when power is cut off and restored, it goes thru a charge cycle. So it appears that the Trik-L-Charge was siphoning power from the LiFePO4 batteries to the engine battery because they hold a higher charge.

78.6AH 13.29V 4/5/14

Refrigerator sent to Indel Webasto 3/15, arrived 3/18. Came back on 3/26.

They replaced: Condensing (Pin) unit BD35F with electronic, schr valve, filter, couplings, fan.