Jump Statt Battery Pack

[Healeyman]

Hi All,

I wanted to use a LI Jump-Start Pack more as a battery power supply to power my in-car brake system, than as an engine starter.

My issue with the one I just bought is that the 12 VDC Power Port (cigarette lighter) output will not Turn ON and STAY hot unless the ON button is repeatedly pushed. It turns off after a few minutes.

The heavy battery cables will not become hot unless a small, residual, voltage is detected.

This (rather expennsive) unit won't light a bulb or spin a motor at all.

It seems to need to be able to sense some electrical power to enable the voltage outputs to energize.

Is this the way they ALL work?

Maybe I should just buy a LI battery and fabricate the needed charge & output cables.

Tim

[time2roll]

Continuous power vs constantly running a battery down? +1 for option 1.

[Y-Guy]

IMHO I'd hands down go with option #1 - it works, simple and effective.

[rjstractor]

Healeyman wrote:
I already have a charge line from the RV to the towed car. While I have not tried it yet, that will probably keep the towed battery charged

I really think you are overthinking this and trying to make something very simple much more complicated than it is. That charge line you have is designed specifically to keep the toad battery charged, and if correctly wired will do just that.

[Grit_dog]

Healeyman wrote:

Grit dog wrote:
Wow, whata weird around about way to try to put power to your toad….

Grit dog,

What would YOU do?

Tim

To quote what you said earlier...

"I have a couple of options:

1) I already have a charge line from the RV to the towed car. While I have not tried it yet, that will probably keep the towed battery charged."

Or am I missing something why the toad battery won't work?

[Healeyman]

Grit dog wrote:
Wow, whata weird around about way to try to put power to your toad….

Grit dog,

What would YOU do?

Tim

[toedtoes]

Grit dog wrote:
And for those that don’t realize it, the little LifePO jump packs like the ones sized to start a say “5 litre” engine, only have enough reserve capacity to charge maybe 2 cell phones.
Again magic is magic and real can never be magic…

The peak amps, starting amps, and capacity vary a LOT on these packs. You really have to check all three numbers to find one that will do what you want.

For me, I have a couple packs that are dedicated for jumpstarting only. I do not use them to charge cell phones, etc. That way I always have a pack ready to jumpstart (it does no good if you've run down its charge on your phone and suddenly need a jumpstart).

I also have a few that I use to power/charge various devices. For these, I worry more about mAH than the other numbers.

[Grit_dog]

And for those that don’t realize it, the little LifePO jump packs like the ones sized to start a say “5 litre” engine, only have enough reserve capacity to charge maybe 2 cell phones.
Again magic is magic and real can never be magic…

[Grit_dog]

Wow, whata weird around about way to try to put power to your toad….

[Healeyman]

I'd like to thank you all for your inputs.

In addition to options 1 & 2 above, I have come up with option 3.

Option 3 = BOTH.

I will go ahead and use the fused and diode charge line that I already have installed. AND I will buy a 20 AMP Li battery, fabricate the input and output cables, and house all of it in a small plastic (Harbor Freight) toolbox for portability.

I find that I can build a more powerful battery power supply system that will do exactly what I want for slightly less than I paid for the Jump-Pack (which I have already returned).

Thanks again,

Tim

[cptqueeg]

Healeyman wrote:
Hi All,

snip....

It seems to need to be able to sense some electrical power to enable the voltage outputs to energize.

Is this the way they ALL work?



Tim

I bought a jumper pack (Schumacher DSR108) that contains a small Li battery but the way the unit functions is it sucks very little juice out of the dead batt to energize an ultra capacitor to do the starting.

Is this the same type of jump starter you bought?

[theoldwizard1]

Healeyman wrote:

My issue with the one I just bought is that the 12 VDC Power Port (cigarette lighter) output will not Turn ON and STAY hot unless the ON button is repeatedly pushed. It turns off after a few minutes.
.
.
.
Is this the way they ALL work?

Many/most do ! It will take some serious shopping to find one that does NOT !

Both DeWalt and Milwaukee make adapters for their batteries so that they can provide USB power and maybe 12V. Any DIY solution needs a charger.

[toedtoes]

I think option #1 is the more effective.

[valhalla360]

willald wrote:
I strongly recommend option #1 - Use a charge line from Motorhome to your towed vehicle.

Unless there is something wrong with the TOAD battery, I don't know why you would consider any other option.

If there is something wrong, probably better to fix it than do a work around.

[willald]

I strongly recommend option #1 - Use a charge line from Motorhome to your towed vehicle.

Will be sooo much cheaper and easier in the long run. No extra battery to have to purchase, wire in, keep charged when not in use, etc. Let the Motorhome's 12V system keep your car's battery charged so it can run the brake system, and don't worry about it.

I did this with the last two vehicles I towed, and it worked great all the years I towed that way. Just plug in the red 6-way cable and forget about it. Nothing fancy is needed, either, just have to make sure you put a fuse on the charge wire right before it goes to your battery.

Current towed vehicle (Jeep Wrangler) does not need this, so did not wire in a charge line when we set it up to tow. The last two did, though, and if the situation ever changed and I needed to keep the battery charged, would be very easy to run the wire to do such.