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!

 

[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" :hehe:

 

[teotwaki]

Dang.

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

 

[Hilldweller]

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

I only tried it one time and that was Thanksgiving a few years ago. I left it on for an hour and it was reading 12.5v so I switched to the Sears charger off the a/c outlet.

I never used the d/c cord after that.

 

[teotwaki]

I only tried it one time and that was Thanksgiving a few years ago. I left it on for an hour and it was reading 12.5v so I switched to the Sears charger off the a/c outlet.

I never used the d/c cord after that.

If you get a chance for a simple test please let me know what the Honda's open circuit DC voltage is like

 

[OptimaJim]

Hi dwh,

I can only reference what we see with chargers here domestically and it is actually quite common to find chargers with AGM and gel settings lumped together. These are three examples from units that are found in several retailers here in the states:





Our engineers did extensive research and gathered quite a bit of data on other chargers on the market, as they were designing our own charger. They do know which chargers tend to overcharge and which ones undercharge, regardless of whether it is charging a flooded or AGM battery and the characteristics of each setting on those chargers. As with a lot of the information we collect, that data is proprietary and I am not allowed to share it.

Jim McIlvaine
eCare Manager, OPTIMA Batteries, Inc.
www.twitter.com/optimabatteries

 

[Skrewball]

Jim, i feel for you man!!

These batteries are not what they used to be...

 

[dwh]

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Holy moley. It's worse than I thought. I figured you might reference one, maybe two, but you pulled out a hat trick.

Yea, those are definitely some seriously screwed up chargers.