Battery wouldn't stay up on terramite

Battery failed me, so I put in a replacement. That battery only lasted a few days and the one I removed charged and was good. Used a voltmeter and sure enough, the charging system wasn't working. Before I bought the terramite, someone had replaced the kohler with a honda. As you can see, the wiring is a spaghetti mess.

So using a little reverse logic, I located the VR, similiar to the old one I had on a Goldwing. Then I followed the wires back to the plug. Saw the heat stress, cut the plug out and wired around it. The two burnt connections went back to flywheel, alternator coils. Now it charges as it should. But I discovered there was a 15 ma drain. Come to find out it was the VR. So I used a 40 amp fan relay I got off ebay. When key is off, power to relay is removed and VR is taken out of circuit. A simple $2 fix.

I purchased 6 40 amp 12v fan relays and the plug off ebay for $2 each. They were shipped from China. Took almost a month. It's hard to find one relay at the stores for that price. I use them all the time. Some complain they can't find a 40 amp toggle switch, so why not use a 40 amp relay controlled by a toggle switch? East fix.

I would say that is useing your head,not to mention some southern engineering to fix a problem. Good point on useing relay for heavy current,starters have used them for years. How many remember stepping on the peg sticking up from car floors to ingage starter? That was a switch subsititing for solinoid and bendex all in one.

The drain on the vr usually means a diode is bad and your hitting the battery with all AC or part AC instead of DC... That would also explain the high current draw and the black connectors. Would get a new vr off or ebay... Hope you havent fried the charge coils yet.....

15ma drain is really nothing. Both alternators on Farmall and Jubilee have a drain too and they
are new. If there was a bad diode, no way my voltage regulator would put out 14.6 charging volts.
BYT, I made this fix 3 weeks ago, 25 hrs on the fix and ALL IS WELL. Measured no AC volts on
battery. Don't think there is really an issue with diodes. I did have to replace regulator on
goldwing. Dealer price was close to $150 and I did the work.

I actually use the Koehler vr on all of my early Honda's...

Trouble with measuring ac voltage is.... that the battery, if good, acts as a capacitor to ac... so you really dont see much on the meter with the battery hooked up, unless its sulphated up really bad. But since ac is being shorted, the high current makes the connectors blacken up while the working diode does a half wave trickle charger as its DC... assuming you have a Y coil with a ground in the middle at the flywheel. Later models I using Rick's charging coils and vrs to bring the level up to a more controlled level..Then on my Nighthawk,, well its an full blown high output alternator sitting on the back of the engine so its a completely different animal.

Glad you got the "termite" fixed. de n5csc...

Mine uses goldwing VR. I have a battery
charger, batteryminder 12248, During
desulfate mode it puts over 30 volt spikes,
3000 Hz to battery. The spikes are of short
duration, small current. Yet I can measure
the AC volts on battery. So much for
battery being a capacitor. If a diode is
bad., it wouldn't make charging voltage and
ripple will be on top of battery voltage.

(quoted from post at 19:45:37 12/11/15) Mine uses goldwing VR. I have a battery
charger, batteryminder 12248, During
desulfate mode it puts over 30 volt spikes,
3000 Hz to battery. The spikes are of short
duration, small current. Yet I can measure
the AC volts on battery. So much for
battery being a capacitor. If a diode is
bad., it wouldn't make charging voltage and
ripple will be on top of battery voltage.

Click to expand...

Using equivalent Capacitance of battery Ah

I=C V/T for lossless battery for ramped voltage

Rb = ESR of battery = V/I []

or in other words ripple V=I*Rb

But if there is series inductance from power source, this integrates the pulse voltage and attenuates ripple..

All capacitors and batteries alike in the same quality, size and voltage range may have different Ah ratings like capacitors have different uF ratings.
From my experience low ESR e-caps are have a C*ESR=T time constant <10 s and smallest <1s, while general purpose (G.P.) caps are > 100 s to > 1000 s in larger sizes.

You can research all battery chemistry and sizes to find the ESR and ESR*C or ESR*Ah product constants for quality and types.

Generally the RdsOn in the Switch must be << Load. Since Rb or ESR of battery is very low (mOhm), the use of SMPS topology raised effective impedance by duty cycle of switch and inductive impedance. But Switch loss is a tradeoff with cost and C/x charge rates and ripple voltage depends on Z=|L| which depends on cost budget, charge rate and pulse frequency

Higher f also adds cost for EMC reduction, but reduces cost of L due to high currents and saturation.


or




All batteries can be approximated as a capacitor with a large series resistance; the series resistance is sufficiently large to give a large time constant for discharge but not large enough for the battery to appear as a constant current source. The "chemistry" within the cell decides the max current available (shorted current) but more importantly it modifies the discharge curve.

or 41-2131/0212/CD 8 www.cdtechno.comThe AC ripple current (IAC) is driven by the AC ripple voltage (VAC) from the charger and will be a function of the cell (battery) internal resistance/impedence (Ri ac) in accordance with ohms law, lAC=VAC/Rac.As can be seen in the equation, lAC=VAC/Rac, the AC ripple current will increase with increasing AC ripple voltage from the charger. Also, note that the AC ripple current for a given AC ripple voltage will vary with the internal resistance of the specific battery. For example, a high rate AGM type of cell with a very low internal resistance will experience a greater AC ripple current than that experienced by a higher resistance gelled electrolyte cell with the same applied AC ripple voltage.