Peter Tourin
2020 Unity RL, ex 2012 Unity MB
My OEM batteries are now toast, and I'm replacing them with SmartBattery SB100's - BCI27 size, 100 AH, 28# each. Installation will be simple since they're slightly smaller than the SRM-27's and have bolt terminals. Charging won't be quite so simple, and I need to replace the 55A charger section in my power center. About time - the power center is a Parallax 7355, which doesn't have a great charger.
I don't know of any drop-in replacement charger that'll charge LiFePO4's. At the moment I'm looking at Progressive Dynamics' 9100L series - they're straight 14.6v chargers designed for lithium batteries - voltage is adjustable, and in any event the batteries want 14.4-14.6. They make several sizes including 60A (input rated 1000W), 70A (1250W) and 80A (1300W). I'd like to install a 70A or 80A charger since the batteries can easily handle the higher charge rate, but the RV has a 30A service.
QUESTION: do I run into problems if I install a larger charger?
The big items are obvious:
Microwave - 1500W convection, 1150 normal (12.5, 9.6A)
AC - 1500W compressor rated load (12.5A)
Charger - 1000, 1250 or 1300W (8.3, 10.5 or 10.9A)
I'd never think of running both microwave and A/C simultaneously (even with the 60W charger I'd be over 30 amps if I ran all 3). So I'm inclined to install either the 70W or the 80W charger. Am I missing anything here? I think some of you have better electric design credentials than I do!
There are 2 drawbacks to the 80W charger - it's physically bigger and it requires a 20A breaker instead of my existing 15A breaker. Both of those issues seem manageable, but the easiest compromise seems to be the 70A charger.
One oddity I saw during my reading: The Dometic site lists specs for the 651815 Penquin II heat pump, and they say the minimum generator size is 3.5 kw. Interesting, given our 2.8 kw units...........
I don't know of any drop-in replacement charger that'll charge LiFePO4's. At the moment I'm looking at Progressive Dynamics' 9100L series - they're straight 14.6v chargers designed for lithium batteries - voltage is adjustable, and in any event the batteries want 14.4-14.6. They make several sizes including 60A (input rated 1000W), 70A (1250W) and 80A (1300W). I'd like to install a 70A or 80A charger since the batteries can easily handle the higher charge rate, but the RV has a 30A service.
QUESTION: do I run into problems if I install a larger charger?
The big items are obvious:
Microwave - 1500W convection, 1150 normal (12.5, 9.6A)
AC - 1500W compressor rated load (12.5A)
Charger - 1000, 1250 or 1300W (8.3, 10.5 or 10.9A)
I'd never think of running both microwave and A/C simultaneously (even with the 60W charger I'd be over 30 amps if I ran all 3). So I'm inclined to install either the 70W or the 80W charger. Am I missing anything here? I think some of you have better electric design credentials than I do!
There are 2 drawbacks to the 80W charger - it's physically bigger and it requires a 20A breaker instead of my existing 15A breaker. Both of those issues seem manageable, but the easiest compromise seems to be the 70A charger.
One oddity I saw during my reading: The Dometic site lists specs for the 651815 Penquin II heat pump, and they say the minimum generator size is 3.5 kw. Interesting, given our 2.8 kw units...........
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