Optima Battery Problems

[teotwaki]

I ran a very quick test tonight and...

<Spoiler Alert> ---- a high end generator's (Yamaha EV1000) 12 volt output is a last resort as a battery charger.


What I did was pull out a digital multimeter and two wire-wound 250 watt 1% resistors. One was 2.67 ohms and the other was 0.5 ohms.

Generator's DC output voltages measured with the "Smart Throttle" switch to OFF:

Open circuit 29 volts DC and 6 volts in the DMM's AC mode, basically ripple voltage

0.5 ohm resistor load measured 5 VDC and noticeably loaded down the generator, probably about 10 Amps DC

2.67 ohm resistor load measured 13.3 VDC and roughly 3 v in the DMM's AC mode, probably about 5 Amps DC


I'd be willing to bet that a similar Honda high end generator is just as poor. Tomorrow I'll check my 3kW Yamaha generator's DC output but I'll bet that the output is similarly as wildly unregulated as my little 1 kW Yamaha


Conclusion: If you ever has to use a generator to charge a battery, monitor the battery closely for voltage and also if possible, temperature.

[dwh]

Holy crap...Infinity...

And Beyond!


buzz_lightyear_to_infinity_and_beyond.jpg

[Hilldweller]

When I sold my Conqueror I had removed the onboard electronics and rewired it a bit. The charger was thirsty and never worked right; it had shorted-out the transformer somewhere between TX & NM anyhow and is still in my garage.

I installed a simple 5 amp boat smart-charger and would plug that in the A/C outlet on the Honda. Worked better than the Sears charger, was quiet, not hot. I fused it with a Blue Sea panel and even rigged an a/c box inside for when it was connected to shore power.

A MUD guy bought it and I think still uses it that way.

[dwh]

Hrmmm...that gives me an idea.

How about a solar charge controller between the generator's so-called "12v" outlet and the battery? A 10a Morningstar PWM would probably work just fine.

For that matter, an MPPT unit might just load the gen's 12v outlet to some optimal power point and hold it there until the battery is done charging.

(And yes, a decent mains charger would work just as well and probably be cheaper. But what the hey, it's something to think about anyway.)

[teotwaki]

Hrmmm...that gives me an idea.

How about a solar charge controller between the generator's so-called "12v" outlet and the battery? A 10a Morningstar PWM would probably work just fine.

For that matter, an MPPT unit might just load the gen's 12v outlet to some optimal power point and hold it there until the battery is done charging.

(And yes, a decent mains charger would work just as well and probably be cheaper. But what the hey, it's something to think about anyway.)

I think that is a very good idea and more efficient than running an AC mains powered charger off of the generator

[teotwaki]

The big Yamaha 3 Kw has 24.5 volts DC open circuit. For grins I put the DC cable clamps on an old wet cell that was at 12.4 volts and the Yamaha ran that thing up to almost 16 volts in a few minutes. Definitely headed for Infinity & Beyond

[dwh]

[Hilldweller]

The big Yamaha 3 Kw has 24.5 volts DC open circuit. For grins I put the DC cable clamps on an old wet cell that was at 12.4 volts and the Yamaha ran that thing up to almost 16 volts in a few minutes. Definitely headed for Infinity & Beyond

Dang.

[teotwaki]

The Johnson Controls approved version is "Tiny Oxygen and Hydrogen Bubbles"

[teotwaki]

Dang.

I'm hoping you didn't leave any of your batteries on your generator for long!