Potable 24 volt DC with two 12 volt DC chargers

Started by B-Red, February 06, 2021, 10:25 AM

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B-Red

One of the winter challenges is moving batteries indoor to remain warm and to trickle charge. I am trying to build a removable battery box c/w built in chargers for my 24 volt light weight.
I am using the dual electronic trickle charger from Can Tire.
I explored the concept of using welder plugs or the concept of using double throw switches.
I am trying to make it idiot proof so I don't short the circuits when I switch to charging or back to car operation.
Ideally, the box will remain in the car during the summer and gets plugged when car is not used.
In Winter, box gets disconnected and moved in the house.
Check my two concept schematics. I am looking for feedback fellows and some hardware ideas.
Emad

B-Red

One more modification would be adding two 12 volt dc outlets for CB radio or fridge.

Red90


B-Red

Quote from: Red90 on February 06, 2021, 12:58 PM
Why not just buy a dual battery charger?
I have one already. However, I have to disconnect the jumper cable to charge the two batteries.
The intent here is to have a black box approach with simple on/off function to switch between charge and drive. Also be removable.

Red90

No. I mean you mount the dual battery charger in the vehicle and plug it is when desired to 120V. This is what I do in all of mine. I use the Noco marine ones. They are waterprooof and do great with a permanent install.  They do a nice 4 Amps dual battery charger that can be hooked up continuously.

B-Red

Quote from: Red90 on February 06, 2021, 03:10 PM
No. I mean you mount the dual battery charger in the vehicle and plug it is when desired to 120V. This is what I do in all of mine. I use the Noco marine ones. They are waterprooof and do great with a permanent install.  They do a nice 4 Amps dual battery charger that can be hooked up continuously.
I need to bring batteries inside. They don't survive well with trickle charge in cold long term.

Red90

They should be fine in the cold with a proper smart charger. Trickle chargers are a bad idea. There is no reason to bring them inside unless you do not plan on keeping them charged.

Trevor

Quote from: Red90 on February 06, 2021, 03:10 PM
No. I mean you mount the dual battery charger in the vehicle and plug it is when desired to 120V. This is what I do in all of mine. I use the Noco marine ones. They are waterprooof and do great with a permanent install.  They do a nice 4 Amps dual battery charger that can be hooked up continuously.

There's a good idea. I'm going to do that with the Disco this summer.
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binch

I picked up on this idea from John years ago and it's been working great!   When I'm not using the 110 I just plug in the 120 to my extension cord and the rest is all set up.    Eazy Peasy
Cheers, Bill

B-Red

I did the dual charge on my red and yellow tops in Tigger. The red failed but the yellow was ok. The cold temperature is hard on these batteries.
However, that's not what am trying to achieve.

Red90

Cold does not hurt the batteries unless they are allowed to be discharged. You either had a charging issue or a bad battery.  Optimas have a well known high failure rate.

ugly_90

#11
You shouldn't need to bring the batteries indoors. As the lightweight isn't being driven over winter, you can simply  charge the batteries in the fall, disconnect your battery posts, and  add a  low-current maintenance charge mid-winter on warmer winter days,  -5C or so.

I use a flooded battery for the 90, at 12V,  but if you have an AGM or spiral wound cells, you may need a gentler charger than an old transformer/rectifier that hums. I use the Canadian Tire 2A smart charger/maintainer, it goes on sale for $20 sometimes. Battery Tender is another make of the same, inexpensive charger for maintenance.

For actually charging a battery, you'll need more jam. We use the Pro Logix PL2320 at work, and I'm looking at the  PL2310 for myself at about $100. These chargers are relabelled and sold as Mac Tools and as Napa US as well. They will handle most battery types. There are 24V versions too, but they're usually more.

I've used a solar panel as well, and probably murdered a used truck battery with it. It was a small panel, barely able to supply enough current to charge over weeks. It didn't have a charge controller/regulator, which was essential.

Out here, you won't get enough sun on a small panel to worry about over current to charging battery, but the cheaper panels have no voltage regulation. You could get 13.8V from it, you could get 34V out at a few mA in the sun, no way to know without a charge controller like the sunsaver brand.

You could also use something like an LM7812 regulator IC and related circuit, after the solar panel. The LM7812 is less than $1. The Sunsaver is like $80.

Red90

To the original plan of having the batteries in a box and being able to easily bring the pair indoors.  I'm not sure that I understand why you feel the need for the switching circuits.

Both batteries mounting inside a suitable box, wired in series.  A intelligent dual battery charger (or two chargers) connected permanently to the batteries and mounted inside the box. A 120V female, panel mount connector mounted to the box wall for supplying power to the charger.  For the 24VDC connection, regular panel mount welder connectors would be the easiest. Or you could just have studs as they would be a bit more secure.


https://www.amazon.ca/NOCO-Genius-GCP1-Black-13-Amp/dp/B009ANV81S/ref=sr_1_3?dchild=1&keywords=block+heater+connector&qid=1612713230&sr=8-3
https://www.amazon.ca/RIVERWELD-Welding-Connector-Plug-DKJ35-50-DKZ35-50/dp/B07MZ7LLB6/ref=sr_1_4?dchild=1&keywords=welder+female+panel+mount&qid=1612713401&sr=8-4

B-Red

Quote from: Red90 on February 07, 2021, 07:04 AM
Cold does not hurt the batteries unless they are allowed to be discharged. You either had a charging issue or a bad battery.  Optimas have a well known high failure rate.
I found that red top optima works well on Petro engines daily drivers. Had it on my Disco without issues. However on My 200TDI, casual driving, red top failed. Yellow top deep cycle holds much better. I am going to use dual deep cycle batteries for Tigger this summer.

B-Red

Quote from: Red90 on February 07, 2021, 09:02 AM
To the original plan of having the batteries in a box and being able to easily bring the pair indoors.  I'm not sure that I understand why you feel the need for the switching circuits.

Both batteries mounting inside a suitable box, wired in series.  A intelligent dual battery charger (or two chargers) connected permanently to the batteries and mounted inside the box. A 120V female, panel mount connector mounted to the box wall for supplying power to the charger.  For the 24VDC connection, regular panel mount welder connectors would be the easiest. Or you could just have studs as they would be a bit more secure.


https://www.amazon.ca/NOCO-Genius-GCP1-Black-13-Amp/dp/B009ANV81S/ref=sr_1_3?dchild=1&keywords=block+heater+connector&qid=1612713230&sr=8-3
https://www.amazon.ca/RIVERWELD-Welding-Connector-Plug-DKJ35-50-DKZ35-50/dp/B07MZ7LLB6/ref=sr_1_4?dchild=1&keywords=welder+female+panel+mount&qid=1612713401&sr=8-4
Thank you John for the links. The euro style plugs are new to me. I will order a set.
The item I was worried about with the chargers is that batteries are wired in series. So I have a positive and negative terminals jumpered together. If I add dual charger, one positive from one side will also be connected with one negative from the second charger. Not sure if this is ok. A simple solution is to add a switch on the jumper cable to break the circuit.
I will play with this configuration and see how it goes. Can tire has a sale on single electronic chargers this week.
Thanks everybody for your input. This helped. Cheers