Cheap maintainer destroyed my battery

Battery about 3 yrs old. I installed the disc switch when I replaced the battery. It is a deep cycle battery. Never been dead. Read 12.0 volts when I took off the treater. Did not check it this morning.

How old is your battery? Do you have a battery disconnect switch? Are you using a deep cycle battery? Have you ran the battery dead before? Need a lot more information to even make a guess.

I'm using a HF tender on my snowmobile battery and it has been perfect now for 4 months! I think your battery was done before you out the tender on it.

cyberiankhatru wrote:
Put a HF "Automatic" charger on my TT battery. After 3 months it has destroyed my battery. All the water boiled out due the charger putting out 20v. Is there any way to save it? Should I have just left it on the TT and let the house panel charge it? I am soooo frustrated!

Your battery was "toast" before you ever put that little "maintainer" on.

20V is the no load voltage, put a load on it and you will find that it drops to 13.2V. It is unregulated and is nothing more than a simple transformer and diode.

It is nothing more than a trickle charger at a 1/2A or so of current, not enough voltage or current to boil a GOOD battery of a decent size (group 24 or larger).

Get a new battery and unless you have a trailer from early 1990s or before you will have at least a two or three stage converter/charger which will have a "storage mode" of about 13.2V which will not boil the water as fast.

cyberiankhatru wrote:

I figure the battery is toasted.

Yes it likely is. 20 V is probably the open circuit voltage of the charger, indicating that no current is flowing to the battery anymore.

Two lessons might be learned here:

A good automatic tender type charger is not very expensive; the few extra dollars would have been money well spent.

Regardless of what the batteries are connected to, they should be checked for water and voltage about once a month.

I fully charge mine then disconnect (switch).
A routine running of the truck and gen once a month keeps them topped up.

Sorry don't know the onboard systems brand. Not where I can check it right now.
I figure the battery is toasted.
Thanks.

With HF you get what you pay for. JMO

Even the DC OUTPUT VOLTAGE of only 13.6VDC that most of the RV Converter/charger use will boil out the battery fluids if left on for a long period of time. By dropping this down to just 13.2VDC stops this from happening according to Progressive Dynamics... This is what the smart mode charging units do keeping your battery safe when setting for a long time.

I learned the hard way as well... Started out in 2008 with four 12VDC Batteries using a single mode 13.6VDC converter/charger 30A unit and lost one battery rather quick by having the battery fluids boiled out. Changed the converter/charger to a smart mode unit and all has been fine since then.

Roy Ken

Hi,

I suspect the battery is done.

What converter is in your RV?

It may be best to charge once a month when an RV is in storage, using a disconnect switch for the "down time" between charges.