Portable battery charger. What do you carry?

[McKenziek]

I've had many over the years but most are cheap and don't last long. I'm looking for a good portable 12 volt Smart charger that can desulfate and get my batteries to full charge if needed.

What do you carry in your RV tool box?

[KJINTF]

This is one of the best explanations I have seen regarding equalization of wet cell batteries - thanks Mex

"Equalization is not like giving the batteries a vitamin pill. It is ONLY done when the specific gravity varies greatly from cell to cell. Equalization SHEDS PERFECTLY GOOD ACTIVE POSITIVE PLATE MATERIAL as well as forces sulfate from coated plates back into solution. What equalization is, is choosing the LEAST OF ALL EVILS to maintain a battery in the best condition you can."

My batteries (Costco CG's) typically last 8 to 10 years, get Equalized no more than once every two years (individually per 6Vdc battery), have their SG checked about twice a year and water added once or at most twice a year. They have never been below 60% SOC and typically stay above 75% while camping. The rig is not used in the winter time.

Not sure if my use/service is "normal" aka typical or not - wondering what others do

[BrianinMichigan]

MEXICOWANDERER wrote:
A separate answer about equalization using the HF. Worst case, using a generator where time is money for fuel and noise is anguish for the ears.

Charge however until you have to modulate (adjust) the voltage so it does not exceed 14.8. When the GC's charge rate reduces to around 18 amperes at 14.8 volts (not the easiest thing to orchestrate)change over to the HF. Try 10 amps. If the voltage surges a lot higher than 14.8 reduce the setting to 2 amps which will probably start out around six to eight. This is where the HF 6 amp charger rather than the 10 amp may be a better choice if this exercise is done on a regular basis.

Let the voltage rise slowly and when it gets to 15.5 re-check the specific gravity with a hydrometer.

Equalization is not like giving the batteries a vitamin pill. It is ONLY done when the specific gravity varies greatly from cell to cell. Equalization SHEDS PERFECTLY GOOD ACTIVE POSITIVE PLATE MATERIAL as well as forces sulfate from coated plates back into solution. What equalization is, is choosing the LEAST OF ALL EVILS to maintain a battery in the best condition you can.

Lastly, any "expert" that tells you a VRB valve regulated battery cannot sulfate is either bending the truth or ignorant of it. They are harder to sulfate and even harder to de-sulfate correctly (without damage). You can tell a VRB is sulfated when it loses capacity at an early age and a strict recharging regimen has not been maintained.

Have you ever IR the temperature of the battery once it gets to 14.8 volts. I was wondering if temp + checking voltage is a effective way of desulfating a battery. The last thing I want to happen is to have a battery explode do to too high of heat.

[pnichols]

KJINTF wrote:
Why do you good folks carry a portable charger?
Help me out what am I missing?
Is it that you do not have an
On board hard wired converter
Or a capable solar system
or the engine alternator is not connected to the battery bank

We have a small Class C motorhome so our "preparedness" choices and methods differ somewhat from those pulling an RV behind a tow vehicle.

We have five ways along with us at all times for charging of our coach battery bank:

1) Converter from built-in generator.

2) Small charger from built-in generator.

3) Converter from portable generator.

4) Charger from portable generator.

5) Alternator from idling of the main engine.

FWIW, all also have five ways along with us at all times for heating and cooling of the coach:

1) Cooling via built-in generator and roof-top A/C.

2) Cooling via cab A/C with the main engine idling.

3) Heating via built-in propane furnace.

4) Heating via built-in generator and a portable electric heater.

5) Heating via the cab heater with the main engine idling.


I was never in the Boy Scouts, but somehow picked up their Plan A/Plan B/Plan C/Plan X tendencies ... especially when out and about in an RV with us not getting any younger so as to have diminishing chances to try again in the future if a trip is spoiled from failed equipment.

[MEXICOWANDERER]

A separate answer about equalization using the HF. Worst case, using a generator where time is money for fuel and noise is anguish for the ears.

Charge however until you have to modulate (adjust) the voltage so it does not exceed 14.8. When the GC's charge rate reduces to around 18 amperes at 14.8 volts (not the easiest thing to orchestrate)change over to the HF. Try 10 amps. If the voltage surges a lot higher than 14.8 reduce the setting to 2 amps which will probably start out around six to eight. This is where the HF 6 amp charger rather than the 10 amp may be a better choice if this exercise is done on a regular basis.

Let the voltage rise slowly and when it gets to 15.5 re-check the specific gravity with a hydrometer.

Equalization is not like giving the batteries a vitamin pill. It is ONLY done when the specific gravity varies greatly from cell to cell. Equalization SHEDS PERFECTLY GOOD ACTIVE POSITIVE PLATE MATERIAL as well as forces sulfate from coated plates back into solution. What equalization is, is choosing the LEAST OF ALL EVILS to maintain a battery in the best condition you can.

Lastly, any "expert" that tells you a VRB valve regulated battery cannot sulfate is either bending the truth or ignorant of it. They are harder to sulfate and even harder to de-sulfate correctly (without damage). You can tell a VRB is sulfated when it loses capacity at an early age and a strict recharging regimen has not been maintained.

[pianotuna]

Hi Mex,

Thanks for translating the Chiglish into English on the "start" setting.

[MEXICOWANDERER]

Hi westend,

With a correctly maximum discharged (50%) group 29, I have instigated FIVE cycles of a Husky 40 amp battery charger and the charge level (acid SG went from 90 to 91 percent charged). I then tried EIGHT desulfation cycles on top of that and the SG did not increase on the hydrometer. So back went the charger for another. Same result. Tried a Black & Decker, not much different. I could not get the battery to fully charge. The maximum charge rate tapers too fast. Voltage droops down from 14.8 way too fast. What a waste of money connected to a generator.

So a DPDT relay connected to a timer now allows a 40 amp charge rate for an hour, switches the almost charger offline and the Harbor Freight online for 4 hours at the 2-amp rate, which usually starts out close to 8. By playing with the timer I can get a pretty full charge.

Yeah I know some three hundred dollar "smart" converters are better, but when I get serious, I slam 300 plus amps into my big battery bank, then taper at the last with the Harbor Freight set at 10 amps on a timer.

For me, common sense and a timer is hard to beat...

IT'S TIME FOR YET ANOTHER DOSE OF....

"The Harbor Freight charger DOES NOT WORK WELL ON AUTOMATIC MODE, and I do not trust it not to fail and destroy a battery. Period. With a dot.

Set the slider switch from AUTOMATIC to START. The dial is CHINAMERICAN mis-marked. START is in really MANUAL. You now have a manual charger, and this is where this charger shines. Superglue the switch to START if you have to."

[MNtundraRet]

You can have the little guys.

I prefer my Schumacher SC-12000A, 6v, 12v, Speed Charger. When I get tired of it I will replace it with their next top-of-the-line (Bad @$$) charger.

:B Mark B.

[westend]

Hi MEXICOWANDERER,
Does the HF charger put out high enough voltage to equalize a pair of GC2's? I know you've posted that the transformers in the HF charger are more than adequate. Have you had the inclination to change the voltage regulation or current output? IOW, have you pimped your HF charger?

For the record, I have an Exide shop-style charger, 2,40, and 200 Amp boost. I carry a small Schumacher 2,6 Amp charger. Looking to fill the gaps between the two and carry something like the B&D or the HF models. FWIW, my solar controller has an equalize function but I'd like the option of a grid powered charger, also.

[liborko]

I carry none but I have disconnected Magnetek 7555 55A switch mode converter still there just in case.

[time2roll]

I carry a Battery Tender 20a charger when in extreme conditions such as well below freezing.

[Bumpyroad]

MEXICOWANDERER wrote:
. It did no good at all screaming "You cost a thousand dollars! You cannot fail me now! You are only three months old!"

you forgot to read addendum "B" on the In case of trouble sheet. The proper fix is:

You #@$%%%$%!!! cost a thousand #@$%%%$%!!! dollars! You cannot fail me now #@$%%%$%!!!"
bumpy

[MEXICOWANDERER]

Many places if you start your engine it means (to the rest of the campground) you are leaving, whether you want to or not. Pull your car up and use jumper cables you will leave just as soon as you get the rig started, or car connected to the trailer.

There is nothing sadder than seeing an individual who worked and dreamed of a vacation for 11-1/2 months who outsmarted himself and had to pull up stakes and head for home 8 days early. Refrigerators in warm country and water heaters in cold country can revolt and produce the same results. When I used to come to Mexico it was with extra ice chests, chargers and a way to heat shower water (solar shower). It did no good at all screaming "You cost a thousand dollars! You cannot fail me now! You are only three months old!"

[mena661]

bka0721 wrote:

My Solar system is very capable, but when your demand use is 150 – 200AmpH a day and you only have 900w,

900W of solar and 1168Ah of battery bank!!! You're definitely my kind of camper!!! Sweet setup!

KJINTF wrote:
I just look at the situation a bit differently from most other folks.

Enjoy your camping we sure do

I don't know if I look at this any different than you do. You DO have the capacity to repair your converter. Most of us don't. That gives you a leg up. I will admit I did not get my B&D as a backup to the converter. Although when my Paramode broke it came in handy until I got the IQ4 module for the IOTA. I can use my Harbor Freight manual charger too. And I have a couple of HF floaters that will go up to 14V that I could use in a pinch. I don't charge while camping so if the converter broke then, I wouldn't know till I got home.

[KJINTF]

Why do you good folks carry a portable charger?
Help me out what am I missing?
Is it that you do not have an
On board hard wired converter
Or a capable solar system
or the engine alternator is not connected to the battery bank

Thanks guys I see everyone has their own and many times unique reasons for carrying a portable charger. I had not thought of many of the concerns that were brought up in the thread.

Me I see no need to store and carry around yet another piece of hardware, got enough******already. We always dry camp aka boondock can't rememeber if we have ever plugged into shore power on the road in the past 30 years. As many have said solar in the shade does not do much, engine alternator is not a real solution. My backup solution is a proper multistage on board hard wired converter powered by an on board 4Kw genset. No worries what so ever about a failure of the converter or genset while on the road. Repaired the fuel pump on the genset while on the road and have repaired a hundred or so converters over the years (none yet while on the road). I just look at the situation a bit differently from most other folks.

Enjoy your camping we sure do

[MrWizard]

Bobbo wrote:

MrWizard wrote:
because things happen
who wants a ruined trip because of discharged batteries and a dead converter
this forum is full of posts about a trip saved from a dead converter or even dead alternator/regulator because of having a portable charger on hand

The only charger I have is my built in PD4655V. If it ever dies on me during a trip, I will get in my car and drive to a hardware store and buy a portable. Seems more efficient to me than carrying a portable for years "just in case."

For me that could easily be 50 or 100 miles
and my 'toad' has two wheels

riding 100-200 miles in bad weather just get something i could easily have carried (bad weather does happen) does not make much sense to me