Trickle charging batteries

[georgelesley]

I recently made trickle charging the batteries easy without being plugged in. I wanted the trickle chargers inside the MH without activating everything that is on when the MH is plugged in. Winnebago specifically says not to leave our model plugged in for Long Storage.

I ran a heavy duty contractor extension cord from the small upper compartment in the propane tank compartment under the chassis to the step well entry area. I enclosed it in the black plastic wire protector shield. In the well step area I installed a wall outlet and installed two fused 12volt plugs directly wired to the batteries, one to the chassis battery, the other one to the coach batteries.

Now charging the batteries is simple. I just run a normal extension cord to the plug in the propane compartment and then plug in the two 12volt plugs and the power strip the chargers are plugged into the outlets for them.

If in the future we have to run a humidifier or anything else, we now have 110v available without plugging the MH in.

[wa8yxm]

You did too much work.. Unlike A/C systems where you are allowed only one power source (Shore or Generator or Inverter) but unless some very special stuff is done (like Honda does with their inverter models) only one...Two will fight

With DC systems, no problem having 2 or 3 or more sources in parallel.. no need to disconnect the charger when it's not in use.. at least if it is properly designed.

That said. Proper design is not always a happening thing.

[pnichols]

George,

Thanks for responding back on my question.

I guess that if one was camping full-time or nearly full time in a campgrounds with electrical hookups, then the converter would probably be on 24/7 with all detectors and electronic circuit boards powered up. When our motorhome is in storage in the backyard between trips, I keep it plugged into 120V AC all the time so that the converter keeps the coach batteries charged up by exposing them to their float voltage - which is the norminal output voltage of the converter. During these times we also keep the chassis battery charged by merely plugging a small trickle/float charger into a 120V AC receptacle in the coach and then plugging it's 12V DC output (it came with both a battery terminal clamp lead and a 12V receptacle plug lead) into a 12V receptacle on the cab's dash. The cab dash 12V receptacles are always hot, so they're always hooked up directly to the chassis battery. This means that the small trickle/float charger is keeping the chassis battery fully charged and maintained 24/7.

Storing our motorhome this way has for years kept it's coach batteries and engine chassis battery maintained in top condition, plus so far ...with no apparent bad affects on any other electrical equipment.

[Sam_Spade]

pnichols wrote:

I wonder what Winnebago's reasoning is behind that?

Batteries aren't supposed to be adversely affected by leaving trickle charge voltage on them continuously -

The problem IS......that to get any charging at all from a simple transformer and diode, the voltage must be well ABOVE the safe float point. And as the battery charge increases, so does the applied voltage. After the battery is fully charged, the applied voltage might be near 15 volts, resulting in more current than is safe for long term float.

An inexpensive single stage converter is about the same as a cheap trickle charger, operationally.

To achieve proper "trickle charge voltage", more properly called "float voltage", the charger must have some "smart" electronics to regulate and ramp down the voltage to achieve proper float.

Batteries ARE adversely affected by leaving a "dumb" charger connected for long periods.

[georgelesley]

pnichols wrote:

georgelesley wrote:
I recently made trickle charging the batteries easy without being plugged in. I wanted the trickle chargers inside the MH without activating everything that is on when the MH is plugged in. Winnebago specifically says not to leave our model plugged in for Long Storage.

I wonder what Winnebago's reasoning is behind that?

Batteries aren't supposed to be adversely affected by leaving trickle charge voltage on them continuously - if this voltage level is the same as leaving the battery's specified floating voltage level on them continuously. We leave our Winnebago Itasca motorhome's converter plugged in and turned on 24/7 whenever it's sitting in the back yard not being used (have been doing this for ~10 years). This is OK for our batteries because their specified float voltage is the same as what the converter nominally puts out under light loads.

Is there some other item/appliance in your Winnebago that is damaged by having battery float voltage levels on them continuously?

The batteries are not the problem, but I think they do not want all the detectors and electronic circuit boards on needlessly. That was my primary motivation also. I also like having separate chargers for the chassis and deep cycle batteries since they are different types of battery and charge differently.

I realize that when traveling all batteries are charged the same way, converter or alternator. But in those cases the charging is usually short term and the converter or alternator carry most of the load and the batteries very little.

[pnichols]

georgelesley wrote:
I recently made trickle charging the batteries easy without being plugged in. I wanted the trickle chargers inside the MH without activating everything that is on when the MH is plugged in. Winnebago specifically says not to leave our model plugged in for Long Storage.

I wonder what Winnebago's reasoning is behind that?

Batteries aren't supposed to be adversely affected by leaving trickle charge voltage on them continuously - if this voltage level is the same as leaving the battery's specified floating voltage level on them continuously. We leave our Winnebago Itasca motorhome's converter plugged in and turned on 24/7 whenever it's sitting in the back yard not being used (have been doing this for ~10 years). This is OK for our batteries because their specified float voltage is the same as what the converter nominally puts out under light loads.

Is there some other item/appliance in your Winnebago that is damaged by having battery float voltage levels on them continuously?

[Bumpyroad]

I did pretty much the same thing on my Chieftain, only I used some heavy duty MinKota trolling motor 12 volt connectors and ust let them hang out from under the step normally
bumpy

[Sam_Spade]

georgelesley wrote:
Winnebago specifically says not to leave our model plugged in for Long Storage.

This is only good advice if you still have their original cheap converter/charger.

IF....you now have a 3 or 4 stage fully automatic charger, that caution is no longer necessary.

Of course, that won't do anything for your chassis battery but connecting a small charger to it directly usually isn't a big deal.

BUT MORE IMPORTANTLY......one should NOT be using a cheap trickle charger to keep your batteries up over long periods of time. You need a fully automatic tender type charger.

Posting what is otherwise good information but tainting it with the term "trickle charger" is really doing a dis-service.

[RoyB]

I don't have too good of luck here just trickle charging the batteries all the time... My trickle charge source is a small 10WATT solar panel laying in the windshield area of my truck or on top of my battery box...

I have to do a full routine of charging my batteries using my trailer smart mode PD9260C converter/charger if I want to have the full performance from the batteries...

I won't go more than a couple of weeks without doing this on my batteries...

Just me I reckon but my batteries are ready to go using this routine...

Roy Ken