Hi there! I am searching the internet
for information on an issue I am having and read some great posts on similar issues on this forum, so decided to see if I can get advice here. I am an RV owner, not a boat
owner, but my equipment
is mostly intended for boating
I have a Balmar
with what is billed as a 280A alternator
- link to the kit is here -
I have a 300Ah Lithium battery
(Nexgen NG300) and a Magnum pure sine wave inverter
. There are also 160W of solar
connected to the battery
rail. The system is isolated from the factory coach 12V system.
So, I have the alternator
, solar panels
and the potentially shore power
(via the Magnum) to charge the battery. I have had the van for about 2 years and it has been working fine as far as I know. I have never been careful or concerned about whether I idle the engine
with shore power
connected and its possible I have idled the engine
while the Magnum is also charging
the battery. It only recently occurred to me this might not be a good thing.
On my most recent trip a couple weeks ago the 10A fuse on the Balmar
12V wire was blown. I noticed this when after a day of driving the battery was not fully charged. The next morning I tried to idle the van to charge the battery, noticed no charge current
and after a few minutes of poking around I saw the blown fuse.
I replaced the fuse, re-started the van and I got charge current
for perhaps 5 minutes and the fuse blew again.
I read a label on the 12V wire that referenced a 15A fuse, so I installed a 15A fuse. This time the fuse didn't blow, but after a couple minutes of charge current the charge current went away and I smelled something overheating
. No smoke, but a definite hot-electronics smell. I decided to drop back down to a 10A fuse. For the remainder of my traveling, I just kept the fuse out and kept the regulator
I am home now and can repeat the symptoms. The best sequence I have to describe is from a test I did this afternoon.
It ran for about 7 minutes before the fuse blew again.
The current readings are coming from the Magnum controller, there is a shunt resistor to measure current in / out of the battery.
CV is 14.3V reported by Balmar. (this is the voltage target for the regulator)
For about 6 minutes –
120A of charge current reported by Magnum controller
BV reported by Balmar – 13.9 – 14.2V
BV reported by Magnum controller in the van – 13.7 – 13.8
Alternator temp – started at 34C, came up to 120C (last temp I saw reported)
Last minute before the fuse blew -
BV reported by Balmar – 13.8V
75A of charge current reported by Magnum controller
It ran this way for a little bit, then the fuse blew.
I suspect something is wrong with the alternator - any advice on further debug or perspectives on what the issue is are welcome!