Battery Tender/Inverter question

Just Mike · 05-23-2022, 08:58 AM

I just replaced the original cheap battery in my camper. It lasted three years so I guess I shouldn't expect much more out of the cheapy, but I have read many threads about OEM inverters not charging batteries well. So, I want to use a Battery Tender I already have to charge the batteries, but I don't know if I need to isolate the inverter from the Battery Tender via the power disconnect. I would like to leave the disconnect switched on so I can run my vent fan during hot/humid weather. I can't think of any reason it might be a problem, but just not sure. Thoughts?

TIA - Mike...

Bigbird65 · 05-23-2022, 09:28 AM

Mike to get the terminology correct a Micro Mini does not come with an inverter, it comes with a WFCO converter to supply 13 volts DC to the trailer and charge the battery. It is an efficient 3 stage charger. I'm not sure why you would want to use an after market battery charger.

Morich · 05-23-2022, 10:28 AM

Just as a point, it is correct that an inverter doesn't charge batteries. It USES battery to "make" AC power!
So for charging, it is a converter. But that can get into all kinds of smallpoints on how we speak as there are inverters, inverter chartger which do both as well as converters which only charge.
No big deal as long as we all know what it is you are wanting to do!

And where more confusion may be getting in is how slow we areto change our thinking. You may have heard that RV built in charging will over charge the batteries and that was true don older RV but things do change and we need to know that the newer Rv do come with much better charging systems than older.
With a 2019 model, you likely do have a good charger but if you have lead acid batteries, it still pays to watch the water and not let them go dry!

But you may also be wondering about letting two chargers of any sort meet each other?
No problems in most cases as one may be putting out slightly different voltage (13.2?) from the other ( 14.0?) but that is no problemand they may both be charging a battery that is way down to 8. 6! One system may make the other reduce it's output voltage sooner as one will almost certainly be slightly different.

DavidM · 05-23-2022, 10:43 AM

If you keep your RV plugged into shore power, the onboard converter (not inverter as noted above) should keep your T/T charged up and the fan running. A separate Battery Tender may not supply enough current to operate the fan, so the batteries could slowly discharge.

BTW I am not a fan of the ubiquitous WFCO 89xx converter. It has only one battery type setting, ie no separate AGM and certainly none for lithium batteries and has a poor charging algorithm. I replaced mine with a Progressive Dynamics and charging performance is much better.

But be that as it may, the WFCO should do fine keeping your batteries charged and the fan running.

David

Just Mike · 05-23-2022, 11:31 AM

Ok thanks for the correction. I forgot these come with converters not inverters. Either way, I know an old camper we had years ago did a poor job of maintaining the battery and that’s why I thought a Battery Tender might do a better job. I have used them for years on motorcycles with good results. I do check the fluid level every couple of months and it is plugged into shore power in the driveway. Maybe I need to rethink this and trust the campers converter to handle charging.