Portable battery charger

Thanks for the links Niner.

So putting it all together I need:
36 amp Megawatt
RC watt meter
Timer
Jumper cables or 10ga wire with clips on one side

Here is where quite a few of us started when we got serious about charging and desulphating our Deep Cycle flooded lead acid batteries.

MegaWatt PSU

Add in a RC watt meter...

RC watt meter, amps, voltage, total amps added, etc.

and lastly, some jumper cables.

10 gauge jumper cables.

Cobble together.

Adjust Voltage with batteries disconnected to 14.8V for bulk charge, on the timer. 2 or 3 hours should do it.

Attach to batteries then set timer and turn on, Intermatic spring wound timers work fine.

After it times out, disconnect and reset voltage to 13.8V, for absorption charging. this might that 12 to 24 hours.

Wet Coast wrote:
Having been recently down the "Charger" path, I would look at getting something like a Progressive Dynamics 9100 series charger and get the optional charge wizard. Throw a high amp connector/plug set on there and battery clamps for general charging and call it done. Don't play with the off the shelf consumer "battery" chargers. It will be the last charger you buy. I know, I now have three different consumer off the shelf chargers of various capacities sitting in the shop.

I was thinking about this as well, looks like the 9200 series comes with a built in wizard.

To the poster talking about 2 chargers, I am looking for just a battery charger and plan to use maintainers when needed, I picked up 2 Stanley's when Lowes had them on sale a few months ago. Mainly I need to keep 3 deep cycles charged for my boats and maybe charge the trailer batteries when there off the trailer like they currently are.

Took my trailer back to the shop Monday and after all the stories on this board about repair shops killing batteries I pulled them and put my oldest group 24 marine cranking battery on the trailer just to have tongue jack power. Figured I would check batteries with the hydrometer and give them a good charge while they were off but my 20 year old Die Hard charger took a dump.

Having been recently down the "Charger" path, I would look at getting something like a Progressive Dynamics 9100 series charger and get the optional charge wizard. Throw a high amp connector/plug set on there and battery clamps for general charging and call it done. Don't play with the off the shelf consumer "battery" chargers. It will be the last charger you buy. I know, I now have three different consumer off the shelf chargers of various capacities sitting in the shop.

My hands seem to be painful today so I am going to plead for help here.

Start off with a MEGAWATT 36-amp power supply. Then a four hour wind-up spring timer INTERMATIC, housed in a PLASTIC duplex box for safety. A 6' 16/3 power cord. A pair of el cheapo 10 gauge jumper cables with one end clamps chopped off.

The parts are on Google and Amazon. Order the parts and I can guarantee forum members will guide you step by step, and this is an EASY project. VELCRO the Intermatic timer to the top of the Megawatt. This thing will actually work and keep working to recharge batteries correctly. All you have to do is trial and error figure out how much time to put on the timer. When you pop the cell covers to charge the battery, look at the liquid inside, when the liquid is bubbling the battery is charged. Just remember roughly how much time it took the time before to charge the battery. The GREAT advantage to this setup is it is lightweight, rugged, and will actually charge a battery to 100% full.

Other Mega and Meanwell owners please chime in!

Muddydogs wrote:
Care to elaborate on the what, where and how for this?

Oh SNAP.
Here we go again.
You just HAD TO ASK, didn't you. :S

You have two needs: Rapid bulk charging, balancing and desulphation, which requires some degree of manual monitoring: That's one charger.

Then during periods of storage or very light use, an automatic float or tender charger is best.

I don't think you will find both sets of features in ONE charger.

But we are about to get 5 pages of theory, details and confusion which will probably end up saying what I said above in two sentences.

MEXICOWANDERER wrote:
If you can tolerate a little do-it-yourself work an adjustable power supply is my choice for a solid-state charger.

I like DIY projects, I'm a handy guy but not sure were to even start with a DIY charger project. Care to elaborate on the what, where and how for this?

Also I'm charging wet cell group 24 and 27 batteries, a couple for the RV and a couple for the boats.

For flooded cells it may be best off with an old fashioned harbor freight transformer type and a variac. Use the variac to control the voltage going into the battery.

Disconnect the battery from the RV and aim at 16 volts @ 25 c (77 f). Monitor the temperature of the battery. If it hits 46 C (115 F), stop the process.

Monitor the specific gravity of the electrolyte.

Disconnecting from the RV is essential as the computer boards are only rated to 15.4 volts.

Equalization for eighty years remains THE approved way to correctly "de-sulfate" a flooded lead acid battery. So-called "pulse charging" is a gimmick. For hundreds of batteries, I compared the energy (kWh) of pulsing a battery versus straight DC current charging kWh are there is not one whit of difference in the amount of hardened sulfation removed from positive plates.

The output of a transformer based charger is half wave 60Hz, from a solid state charger the pulses are according to the frequency of the PWM signal. How did I PROVE THIS? By dis assembly - and using a 20X loupe and actually examining cell by cell, plate by plate the results of the tests. Had pulse charging been authentic I would have patented it, and made millions. NO ONE and I mean ZERO firms had the high frequency or high current adjustable power that I was using. I had to admit defeat. One manufacturer offered me more than seven hundred thousand dollars to put my credentials on the line behind their product. I refused. Call me stupid. This is the age of cheaters and liars. Charger manufacturers who CLAIM their product is "Patented" either hold no patent at all or the patent is for some other feature on their charger. Please read up on the difference between PATENT PENDING and a genuine patent.

Lots of "smart portable battery charger" companies are in hot water financially because of warranty returns. If you can tolerate a little do-it-yourself work an adjustable power supply is my choice for a solid-state charger. As far as gizmo chargers are concerned I can offer no advice except I have several that stopped charging and are now designated as a waste of natural resources.