Battery Chargers - Tech Talk 101

[anndel]

I have a 30 year old Sears Craftsman and a NOCO Genius G7200. Love both and they work great.

 

[larrymoencurly]

There is a huge amount of snake oil, smoke & mirrors in batteries and general and chargers specifically. I personally wouldn't spend much on any technology.

I checked companies that make chips that control battery charging, like Texas Instruments, Maxim, and Linear, and their devices don't seem to pulse charge lead-acid batteries, only for NiMHs and NiCads after regular charging was done, to prevent metallic whiskers from growing on the plates and shorting them together. Basically for lead-acid, the chips just tried to make the batteries reach around 14.x - 15.x volts and then maintained that or would shut off. Apparently there's no need to use high currents like 30A for a 60A*H for AGM batteries, and slow charging is perfectly fine. But apparently fast charging is desirable for NiMHs and NiCads because that makes it easier to detect rate of change of voltage or temperature, and it's really desirable for lithium batteries, which require much more accurate measurement of voltage, current, or temperature, especially during the 2nd phase of charging, after full 4.0V - 4.1V per cell is reached, because lithiums are more easily damaged by lithiums -- there's no trickle charging of them at all.

 

[All]

I checked companies that make chips that control battery charging, like Texas Instruments, Maxim, and Linear, and their devices don't seem to pulse charge lead-acid batteries... to prevent metallic whiskers from growing on the plates and shorting them together. Basically for lead-acid, the chips just tried to make the batteries reach around 14.x - 15.x volts and then maintained that or would shut off. .

The CTEK Multi US 25000 charger DOES pulse lead acid batteries, during the 8th stage of the charging cycle. During the maintenance phase, "the battery receives a pulse when the voltage sinks, keeping the battery in good shape when it is not being used. The charger can be connected for months at a time. Pulse - Maintenance is indicated by Lamp 4."

CTEK also shows a diagram of the voltage and current pulsing on the charging stage map.

The CTEK company is based in Sweden, and the design of the unit apparently occurred there. Perhaps they are using a controller chip from a European or Japanese source, or perhaps they've developed their own controller chip.

 

[cashishift]

So it appears the NOCO units are NO GOOD?

 

[Qualitytools]

I just became aware of the CTEK brand and have been reading up on it and viewing videos of their products. Very impressive and expensive but than again new batteries are expensive also.

 

[Danglerb]

I have a Schumacher smart charger and an ancient Western Auto 6 amp charger and use both. The Western Auto is dumb, transformer, bridge rectifier, with a constant heavily modulated by the 60 Hz sine wave bumps otherwise fixed voltage output, which means it charges even totally dead batteries the smart charger refuses to charge.

The big change in chargers is that big input transformers aren't needed because of PC style high frequency switching directly from the AC input allows very high power from palm sized transformers, usually toroids (donuts). Along with the smarts could the "safety" features like not charging a fully dead battery and different charging modes.

Every type of battery has a "best" method of charging, in some cases it makes a large difference in battery life, others not so much, as all car batteries at least have to work in a wide range of cars from many ages.

Batteries are still regular replacement items, and chargers are getting in some ways better, as well as generally cheaper. Don't get carried away by a big empty box charger, or a fancy expensive battery.

 

[kblee27]

I use a switching power supply smart charger (samlex america) and also adjustable DC power supplies.
I charge plenty of batteries every week.
My ctek went dead after 2 yrs.