Good idea or bad idea?

[stevejones]

So after posting a question on a thread concerning the Kodiak Solar Generator I had an idea that I wanted to run past the battery/solar power knowledgeable folks here.

I have a 2019 Globetrotter that has factory solar, so it has two AGM GPL-24 batteries. In addition to the roof top solar panels and controller, it has a ZAMP type external port for hooking up a portable solar panel. This external port is attached directly to the two batteries in the battery box. It is not connected to the solar controller.

So this is the thought. To get one or two additional AGM GPL-24 batteries, the same as what is in the trailer now, and put them in some sort of box to store/transport/keep them in. I could hook a portable solar panel to these batteries during the day to charge them. When I needed extra battery power I could connect them to the house batteries using a ZAMP connector connected to the ZAMP external port, allowing easy plug in of the extra power.

This would be a lot less expensive than something like a Kodiak Solar Generator and would provide a decent level of additional 12 V power.

Good idea or bad idea?

Thanks

Steve

[turk123]

I believe a bad idea unless there is some way to increase the size of the wiring from the zamp connector. The connector itself is not right either. Too small and scary for that kind of amps

You could add another solar controller with panels to go directly through the zamp connector to increase the charging rate.

There are more knowledgeable people here with electronics than me, but I would not trust the gauge of wire.

[uncle_bob]

Hi

The Zamp connector is good for around 10 amps or so. You might get a bit more through it, but that's not a great idea. You (hopefully) have a fuse in the line with the connector. Given the wide variety of installs .... who knows for sure.

When you hook charged batteries to less charged batteries, they try to "work out" the difference. That can result in a *lot* of current flowing. Having those currents be up in the 30 to 50A range is possible.

Net result ... fried connector / blown fuse.

====

Much better alternative - find a location to stow the two extra batteries and keep things hooked up all the time. (understand the venting requirements for any battery enclosure first).

Much more expensive alternative - swap out the lead acid's for Lithium's.

Alternate solution - get a simple little inverter generator.

Lots of options.

Bob

[ROBERT CROSS]

snip...."that kind of amps"

Do I assume correctly... you have eliminated the Kodiak idea.😳

??? our portable 120w Zamp puts out 6.8a.
The wiring is not the big concern for the addition of a 120-150w portable.

I believe your plan would work...but as the other Bob noted better options are in the ethos. 😏
An LP multi-fuel generator is a very cost effective option.
Paying no attention to the vociferous negative generator proclamations. 😂



Bob
🇺🇸

[stevejones]

Thanks for quick replies on this topic.

So what if I scrapped the part of this plan to use the ZAMP connector to hook up to the house batteries and just used instead jumper cables?

Thanks,

Steve

[ROBERT CROSS]

Originally Posted by stevejones

Thanks for quick replies on this topic.

So what if I scrapped the part of this plan to use the ZAMP connector to hook up to the house batteries and just used instead jumper cables?

Thanks,

Steve

If you can easily get to them it will work very well.

I tested that method when we first got the Zamp, worked fine, positive on one battery negative on the other. 👍

The Zamp suitcase came with the cables that clamp directly to the battery terminals.


Bob
🇺🇸

[uncle_bob]

Originally Posted by stevejones

Thanks for quick replies on this topic.

So what if I scrapped the part of this plan to use the ZAMP connector to hook up to the house batteries and just used instead jumper cables?

Thanks,

Steve

Hi

If you have used jumper cables a lot, you know that sometimes they make good connection ... sometimes they don't. The difference is rarely obvious when you hook them up. A poor connection run for a while generates heat. That can do damage. Not a big deal, but something to think about.

There are connectors (and cables) designed for this sort of thing. Way better to just install a set of them and be done with it.

Bob

[cazual6]

I think you are on the right track. Once you get the wire gauge size down, I think it will be a good idea.

[guskmg]

If i were pluging in any high amperage device directlly to the batteries, I would use welding wire, plugs and sockets. They are color coded and therefore safer. Ask a welding supply store about available wire size.
guskmg

[ROBERT CROSS]

10a charge, high...welding cables?

Bob
🇺🇸

[vintagemotor]

I recommend when connecting auxiliary batteries, use properly rated Quick Connector:
https://www.amazon.com/dp/B0129E1KF8...d-f9d1f1abea37

You can get ones with a mounting bracket that can be placed near the battery box.

[uncle_bob]

Originally Posted by ROBERT CROSS

10a charge, high...welding cables?

Bob
🇺🇸

Hi

Yes, when the battery sets try to equalize voltage, you will get a *lot* more than 10A of current.

Bob

[ROBERT CROSS]

Originally Posted by uncle_bob

Hi

Yes, when the battery sets try to equalize voltage, you will get a *lot* more than 10A of current.

Bob

Thats unusual, Zamp supplies 10g wiring on the 120w 10a solar suitcase. Pos on one battery neg on the other.
7 days charging SFSG.

Bob
🇺🇸

[uncle_bob]

Originally Posted by ROBERT CROSS

Thats unusual, Zamp supplies 10g wiring on the 120w 10a solar suitcase. Pos on one battery neg on the other.
7 days charging SFSG.

Bob
🇺🇸

Hi

.... but we're talking about hooking up an external pair of group 24 lead acid batteries via the Zamp plug. You *will* have a lot of amps available in that case.

Bob

[ROBERT CROSS]

My mistake? I mis-understood the OP, thought he would charge & swap not charge & jump. 😂

Bob
🇺🇸

[uncle_bob]

Originally Posted by ROBERT CROSS

My mistake? I mis-understood the OP, thought he would charge & swap not charge & jump. 😂

Bob
🇺🇸

Hi

We've now gone off into that loop as well .....

Bob

[Tony Lee]

Fit heavy cables and Anderson plugs or similar if you are going to connect two lots of batteries together. (almost all factory wiring for addons is barely adequate for even the factory-intended use let alone anything larget)