Jumping a Battery

The Red is Positive, Black is Negative. Be sure to run Black to the engine, frame or - on battery. You can leave a charger hooked up and mos RVs when plugged in have a charger hooked to the battery. Pull the cables off, clean with a post cleaning brush, spray with battery cable protectant and return to service. You can pull batteries and have them tested at most Auto parts stores.

RayJayco wrote:


Red to dead, red to good, black from good to under the hood (some good metal and NOT the good battery terminal)

Can you explain this a little for the once-a-year mechanic?

Smitty had a good jump sequence.
The one that I have always remembered:

Red to dead, red to good, black from good to under the hood (some good metal and NOT the good battery terminal)

Only hook black to dead battery to keep from possibly harming the good battery...

Reverse for removing and as a note,
hook black to bad battery before hooking good battery black to metal.

I hope this helps someone!

unless you have a real jump starter charger most the others do not work very good. i have one of these there older model bought 30 years ago and has always started any good running vehicle with a low battery i have used it on. has a real 200 amp boost. SCHUMACHER SE-3010

Is it ok to start with a battery charger attached????

YES. but...

Most modern battery "Smart Chargers" which by the way are the only kind I recommend, Even have a special setting for it.

My latest "Automotive" purchase (not counting tires and gas) is a Deltran Battery Dender Delux. It has 3 modes

Default: Battery tender 1-2 amps. fully automatic
Battery boost: 20 amps. runs things up to 14.1 VOlts and then drops down to Default (Tender) NO auto return to boost mode.

JUMP START 70 amps for 1/2 minute max (I think, not sure of the time lmit)

Last one I had. also had a Jump start mode. it wore out.

SOME of the older chargers.. Might have an issue but .. I doubt it.

I'll add a few more items to the above:)!

-Connect positive cable first, when getting ready. (Disconnect negative cable first, when done and removing cables.)
(Can't stress this enough. Batteries can outgas, and if tight areas this outgas can linger, and sparks can result in explosions.) Memorize the sequence! (My mechanic neighbor, helped me with my first jump of a a car. And I always remember and appreciate him taking the time to explain the safety aspects. He used the line 'Positive to use positive first on connecting. Reverse when disconnecting'. I've always remembered 'Positive to use positive first...' line:)!).

-As mentioned, even medium size chargers can have a 50A setting. Once you connect this, don't walk away and leave it. But, do let it push a little juice into the battery. With 50A, I usually wait at least 1 1/2 minutes, before trying to start. When jumping from another vehicle, I wait 2 full minutes before trying to start.)

-As reasonably soon as possible after starting, disconnect (Negative first!) the cables. (And I always turn the charger Off, before Connecting and or Disconnecting cables.)

Safety is a discipline of mind over the instincts of just wanting to get something done!!! Safety takes thinking, and consistent safe practices...

Off my band wagon now, was getting a nose bleed - so good thing. Off now to go beat some other drum...

Best to all,
Smitty

Sure.

Some chargers have a high-amperage 'start' feature.. but you can't leave it on very long. If not, leave the charger on for a few minutes before attempting to start.

sealevel ram wrote:
Is it OK to start a MH (or any other vehicle) with a battery charger attached?

In other words, use the charger as a jumper?

I have one of those portable jump starter things, but it doesn't appear to be working great.

Thanks.

Well,
Yes and no. The very first things to consider here are the coaches battery connections. While some connections LOOK good, they in fact are not. Removal of them will reveal corrosion and poor contact. And, many RV DIY types, focus on the POSITIVE cable connections without paying any attention to the NEGATIVE ends. I've seen many, many negative ends attached to the frame, with tons of rust, corrosion, road debris etc. all around those connections.

And, once the corrosion starts at an end, it can easily migrate up the cable. So, with all that being said, make sure your connections (at both ends) are in great shape and, also, make sure you're not dealing with a battery or, batteries, that have potentially dead cells. If you have a dead cell, all the jumpers in the world ain't gonna help your situation.

If your batteries are in great shape and, your cables too but, you simply left an accessory on which drained them to the point of not enough cranking amps left, yes, those little Jumper packs should do the job. Mine has a 600 amp rating. I tested it on our dead truck one time and, it started that truck better than the original battery did.
Scott

Yes however, keep in mind that most chargers simply don't have enough current to be able to start a car let alone a motorhome. It can take 90 - 300 amps instantaneous draw to start a vehicle. Most "chargers" can deliver 1 - 50 amps. Some "converters" can produce 30 - 160 amps but they are designed for hotel loads not massive inductive motor loads. The problem with most "jump" boxes is insufficient capacity for motorhomes and poor connections. It requires a really good connection to pass a large amp draw otherwise a lot is lost as heat. Understand that turning over a large engine requires a lot of energy. All of this said using a charger to charge the chassis battery can allow you to get enough charge to start the vehicle. Most common motorhome manufacturers provide a "boost" switch to allow the motorhome be started from the house batteries. I would recommend that method in most cases.

Your DP probably has two 800+ CCA batteries and your jump pack has maybe 200-400CCA...not going to do much for a Diesel engine. Why not use your boost switch which could add 1000 CCA.