jump starting 6 volt

The best solution is to keep at least one more 6 volt tractor on hand to jump your WF. Second best is a battery maintainer. I've heard you can use 12 volts on a 6 but it's risky.   

Sounds like a battery maintainer would be just what you need.

http://www.amazon.com/Deltran-Battery-Tender-Plus-Volt/dp/B004V9FD58/ref=sr_1_9?ie=UTF8&qid=1312637897&sr=8-9

I think the more important thing to do is figure out why the battery keeps dieing. I there something draining it or is the battery in need of replacement? I have found the best fix is to install an isolator disconnect switch to disconnect the battery between uses, or just pull one of the leads off. This should keep a good battery from draining.

Now you've lost me.
First you say to find the problem and then you say to put a battery switch in to bypass the problem.

Before I learned 6v systems need 02 ga minimum cables, 00 is better, I jumped a 6v tractor off a 12v pickup too many times to count. It is totally safe to do it that way. Measure the open circuit voltage of a non regulated battery charger. You just have to remember that you make the last connection AWAY from the dead/discharged battery. Battery explosions come from sparks in the presence of hydrogen gas from a charging battery.

The 'battery booster' that you have probably isn't powerful enough to do damage, they're usually just strong enough to add 'a little' when cranking.  If you have a magneto system, or there's enough charge to run the ignition, use the hand-crank... if the fuel system is set right, it should light up after one-and-a-half turns... that's my acid-test for proper tuning- if I can light it up with the hand-crank on the 3rd compression point, it's right... and it starts really well on the starter, too!

But yeah, if you don't have thick cables and good connections, it'll give you fits.

As far as the battery going dead... how FAST does it go down?  If it goes down overnight, I'd say you've either got a shorted plate, a cracked busbar, or got something drawing current that shouldn't.

The latter is easiest to detect... the former will be pretty darned obvious while detecting the latter:

Unhook the battery ground cable, pop the caps, and check water level. 
IF you see inconsistent water levels, STOP!  Inconsistent water levels mean that one or more cells are carrying load, while the others aren't.  A shorted cell will use little or no water.  A contaminated cell will use ALL.  If you see either case, replace the battery- don't try to recover it, you'll find yourself taking a shower of acidy fire.

If it passes the initial inspection, top all cells with distilled water, and test each with a hydrometer.  They should all be about the same.  If not, you have a contamination problem on the bad cell(s).  If so, replace the battery.

Next... Measure the battery voltage and write it down on your inkboard, along with the time and date.  Make sure you've left good ventilation, put a small charger on it... say... 1A or less, and walk away.  Come back in several hours.  Unplug charger, walk away for 5 minutes, then measure and write it down.  Repeat for about a day, or until it reaches a fair state-of-charge.  If it's up around 6.5v or so, let it cool for a bit, then check water levels.  If it's holding steady, it's good- ventilate the area, check your cables and connections (Gerald noted, and it can't be stressed enough- SHINY CLEAN!) and give it another try.

But fair warning-   the don't's are pretty clear:

Don't disconnect or connect a battery charger with the charger plugged in.  Make the connections with the charger unplugged, and preferably, a dozen feet away or so.  Reason being- when you make or break charging connections, you WILL generate a spark.  The battery generates hydrogen gas, and there's oxygen present, so there's a very, very high risk of igniting the hydrogen.  By using a dropcord, and making your connection farther away, the likelyhood of ignition is much lower.  Good ventilation is a must.

Next- one of the most dangerous things you can do, is try to revive a battery which failed the above tests.  The ONLY battery explosion I ever experienced, was due to a cracked internal busbar... not cracked enough to fail the above tests, but after charging, I disconnected power from the charger, unhooked the charging clips, donned my shield and gloves to give it a hydrometer test.  The battery exploded about 15 seconds AFTER I'd disconnected the charger as a result of the internal busbar creating a spark.  It blew my shield off, and deafened me for about 20 minutes.  Make no small point about it- I did everything correctly, and it still happened.  Had the battery been translucent, I would have seen that the electrolyte level in the cells was not symmetrical, but the case was black, and the caps were sitting across (but not in) the cell fillers to keep debris out... I wouldn't have had a chance to see 'em 'till after the shield was on, and I was looking right down the caps.  It lit up before I even got to 'em.  So, if you EVER suspect you have a battery problem... if it ever passes the tests I noted, leave it dead- take it out, and get a new one.

Gerald J. wrote: But Brian, while the open circuit voltage of the unregulated charger is high, its also current limited to maybe 10 or 12 amps while the available current from a good 12 volt battery can be a couple kilo amps which is enough to blow up a 6 volt battery if it objects to the rapid charging. My dad blew up a 6 volt battery once from a welding spark while it was being charged by a 3 brush generator and within a minute or two all his clothes facing the battery were gone, two layers, down to skin. He got himself a quick shower. The latest 1.5 amp battery keepers sold at wallyworld for $20 automatically select 6 or 12 volts and are doing a find job on 12 volt batteries around here. Nothing I own now came with 6 volts so I've not tested that feature. A 6 volt system may not crank from several problems primarily a super sensitivity to bad battery post connections that need to be cleaned regularly, probably as often as some use the tractor. There just isn't much tolerance for a poor connection in a 6 volt starting circuit and acid fumes from the battery are working on wrecking those post connections 24/7 whether used or not. Gerald J.

No, not in all cases. One of my chargers has a 40 amp charge continuous capacity.

Brian- what's the OCV of your charger, and how many amps do you load it to 'till it's down in the acceptance-charge level?

Typical 'simple' chargers are just a center-tapped transformer and two half-wave rectifiers... the secondary windings are frequently heavy, but the manufacturers are careful to run primary winding resistance and core design which naturally limits secondary current to a safe level.  Really neat industrial chargers run buck-boost windings like SOLA CVTs, and they're especially nice to have if you actually have one that works at a voltage useful for common batteries.  Newer types will run SCRs and 'clip' the AC waveform, so they'll bulk without swinging high.  Not that it has any big impact on the OP's circumstances, just an observation.  I wouldn't want to impose a high-current charge on a battery for very long- it's pretty hard on batteries, and non-savvy individuals tend to do things like put 20A chargers on lawn-garden batteries... and wonder why they're dry the next day.


Edited by DaveKamp - 06 Aug 2011 at 6:34pm