How bad are converters on batteries?

[afidel]

I'm finishing up my first trip out and about to put the trailer into storage for the next 4-5 months. I have indoor climate controlled storage with power available. My question is how bad will a modern 3 stage converter really be to a marine battery over that period of time. Do I really need to go out and buy a charger that costs half as much as a new battery (I can't imagine the cheap Chinese junk is any better than the converter) or will I still have a working battery come Spring? Also what is the failure mode for overcharged lead acid batteries? Any chance for fire or flames?

[Veebyes]

Charge em up then disconnect em. No need to leave a charger on. Pay a visit once a month, even once every 2 months, connect up & top up charge. If the batterys a good the recovery will not take long at all.

Farmers & construction companies leave equipment unattended for months at a time. No chargers on them. Same wet cell batteries that RVers use.

[dodge_guy]

Why not just get a maintainer and hook that up to the battery. They are only $20-50 and are automatic.

[afidel]

rskrbina wrote:

afidel wrote:

time2roll wrote:
If that modern converter is a WFCO all bets are off. Measure the voltage after a week and see if you actually see storage mode at 13.2 volts.

Regardless you still need to check the water level periodically.

See, that was my worry. It's a two hour round trip (during good weather) to my storage so the chances of me going during the next few months are pretty much nill. I think I'll pick up a timer and just set it to go for an hour or two a day which should be plenty to keep up with the small parasitic loss from the CO/LP detector and the stereo (or should I pull the stereo fuse?).

Hello Andy. Use your battery disconnect switch and you won't have to worry about parasitic loads while storing your rv.

None in my trailer and I was going to add one but the most logical place would be at the tongue box but then the converter can't keep it topped up and 5 months of loss would be bad for battery health. I think I'll just try with the converter on a timer this season and see how it goes.

[afidel]

theoldwizard1 wrote:
If you are concerned about overcharging, buy a cheap mechanical lamp timer and install it between the power source and the charger. Set it to run for a couple hours per day.

Next time you are shopping for a house battery make sure to get a TRUE deep discharge battery. Most "marine" batteries are dual purpose and therefore are a compromise between starting and powering things.

Yup, plan to upgrade to 2x golf cart batteries, the marine unit was what the dealer included in their prep package and I'm not even sure how much dry camping we'll be doing.

[rskrbina]

afidel wrote:

time2roll wrote:
If that modern converter is a WFCO all bets are off. Measure the voltage after a week and see if you actually see storage mode at 13.2 volts.

Regardless you still need to check the water level periodically.

See, that was my worry. It's a two hour round trip (during good weather) to my storage so the chances of me going during the next few months are pretty much nill. I think I'll pick up a timer and just set it to go for an hour or two a day which should be plenty to keep up with the small parasitic loss from the CO/LP detector and the stereo (or should I pull the stereo fuse?).

Hello Andy. Use your battery disconnect switch and you won't have to worry about parasitic loads while storing your rv.

Sorry, I read your post a little closer, please disregard.

[ksg5000]

sonora wrote:
Would a mid 90's converter be an "older" one?

Maybe/probably? If you know the model number - post. If you don't have ready access then measure the electric output ... older converters often put out a constant 13.6 volts which tended to deplete the battery water and those who didn't maintain water ended up with dead batteries.

[Matt_Colie]

sonora wrote:
Would a mid 90's converter be an "older" one?

Sorry,
But without the make and model number, nobody can tell you. There were some good converters at that time, but they were few.

Matt

[wa8yxm]

Well.. you stated a modern 3-stage converter.

A good 3-stage will baby your batteries and not damage them at all.

HOWEVFER, that said yes, there are failure modes.. The most COMMON failure mode for the converter most likely to fail is "Wont' go into Bulk (or Boost) mode,, This will not damage your batteries.. Just takes forever to re-dcharge when you are using the RV.

There are other failure modes however

NO CHARGE, period, total failure of converter.. This Short term, won't hurt anything but the batteries over time will run down

And the other failure mode which is very rare is over voltage (Leaky pass transistor for examnple) this will boil the batteries dry over time, and if allowed to continue can, in theory, cause a minor explosion and a major fire.

But,,,, in 12 years of cursing the forums.. I have NEVER heard of that from a modern 3 stage converter. Only from one that was discontinued last century and then no fires.. Just dry batteries.

[BarneyS]

sonora wrote:

Ava wrote:
It is the older converters that do not have a three stage charging cycle that are hard on batteries. The continuous charge on older units can boil the battery dry if not checked on regularly as far as I understand.

Would a mid 90's converter be an "older" one?

Yes,chances are good it is an older one.
If you would post the make and model of your converter someone will be able to tell you whether it is a "modern" one with the 3 or 4 stage charging circuit.
Barney

[cyntdon2010]

check battery water every month..

[prichardson]

I would charge fully, ensure proper water level, make sure the top is clean and dry and disconnect the battery. With any charging system, the water level needs to be monitored.

[sonora]

Ava wrote:
It is the older converters that do not have a three stage charging cycle that are hard on batteries. The continuous charge on older units can boil the battery dry if not checked on regularly as far as I understand.

Would a mid 90's converter be an "older" one?

[afidel]

time2roll wrote:
If that modern converter is a WFCO all bets are off. Measure the voltage after a week and see if you actually see storage mode at 13.2 volts.

Regardless you still need to check the water level periodically.

See, that was my worry. It's a two hour round trip (during good weather) to my storage so the chances of me going during the next few months are pretty much nill. I think I'll pick up a timer and just set it to go for an hour or two a day which should be plenty to keep up with the small parasitic loss from the CO/LP detector and the stereo (or should I pull the stereo fuse?).

[SoundGuy]

afidel wrote:
I have indoor climate controlled storage with power available. My question is how bad will a modern 3 stage converter really be to a marine battery over that period of time. Do I really need to go out and buy a charger that costs half as much as a new battery ...

Lucky you with indoor heated storage with power! :B If I had that luxury I'd just make sure the battery was properly watered and plug the trailer into power so the converter can maintain battery charge. If that doesn't suit you remove the battery, take it home, and invest in a good stand alone charger ... so what if it costs "half as much as a new battery"? ... it's cost amortized over the many years you'll use it will amount to pennies a day.