3901 battery tender

[Buffalo]

I have a 2015 L3901. Last year I put a battery tender on it, and after a couple of weeks it threw a code, basically indicating "over voltage". I took the battery tender off, cleared the code, and have had no more trouble.

I want to put a switch on the battery to have the battery disconnected while it is on a tender, and connected otherwise. No problem.

However ... given the tricky electronics on the 3901, is there a downside to effectively having the tractor sitting without a battery at all for most of the time ?

 

[85Hokie]

not sure what "tender" you were using - did you by chance UNPLUG the tender and hit the key?

depending on the charging voltage - that battery could be holding 14.5 volts for the short time you had between unplugging and starting.

The tenders I use - do charge the battery - but in pulses, and then checks to see how the battery responses to those pulses...... once it get to about 12.8 or so the charger goes to sleep......... until such time when it is needed again.

 

[GreensvilleJay]

'technically' it shouldn't matter if the battery is disconnected from the tractor. NO electronics to worry about ,after all the key is off. Battery is 'disconnected' when you replace it, same story right ?
it is possible the 'battery tender' charged the battery to a higher voltage than the 'computer' was programmed to say 'ok'. I don't know what voltage your computer says is 'over voltage' ,or what the 'tender' puts out.
Say the tender gave the battery 12.45, and the computer 'over voltage threshold' is 12.40. By the numbers, yes it's over. Reality though numbers are the same...about 12 and a half volts.
All batteries have a 'surface charge' just after charging, takes a few minutes to 'relax' down to the stable, real voltage( once the chemicals balance out...) If you turn on the headlights, just after a tender cycle,the battery voltage will drop.Maybe then the computer will be happy.

Honda CRV computer had O2 sensor preheat value tables( the 'default' values) WRONG, would give error codes,yet during real ,up the pipe, Etest readings were well within spec.even with Honda O2 sensor(5x$$) ,you'ld get 'bad' readings....

 

[JimmyJazz]

I have a BMW motorcycle with lots of fancy electronics. The battery removal process is similar to performing a liver transplant. Complex. After spending an hour or two online I discovered the Optimate4 charger. Works great. I can leave the battery installed and charge it thru the Can-bus port. These apparently are sold all over the world as the box has directions in 6 different languages. Seems very sophisticated. On the box it says "Connect and forget" and that's what I have done. Maybe it would suit your set up. Good luck.

 

[fried1765]

I have a BMW motorcycle with lots of fancy electronics. The battery removal process is similar to performing a liver transplant. Complex. After spending an hour or two online I discovered the Optimate4 charger. Works great. I can leave the battery installed and charge it thru the Can-bus port. These apparently are sold all over the world as the box has directions in 6 different languages. Seems very sophisticated. On the box it says "Connect and forget" and that's what I have done. Maybe it would suit your set up. Good luck.

There are "Battery Tenders", and then there are battery tenders.
I would not trust a HF "battery tender" any further than I could throw it.
I only buy high quality units (I have 13 - several brands), because I like to think they may not burn my buildings down.

 

[MapleLeafFarmer]

There are "Battery Tenders", and then there are battery tenders.
I would not trust a HF "battery tender" any further than I could throw it.
I only buy high quality units (I have 13 - several brands), because I like to think they may not burn my buildings down.

well said!

 

[DustyRusty]

I have been using a NOCO Genius battery maintainer for the past 5 years, and it works using the principle of sensing the voltage of the battery and pulsing the current to prevent sulfation of the cells. I have one on my 4 cylinder diesel generator and that battery is about 8 years old and will start the generator no matter how cold it is outside. I buy Delco Professional batteries when I require dependability to start every time, like on my generator. Should the battery develop a bad cell, the Genius will give you a visual signal with a blinking light. They are available in multiple assortments of amperage.

 

[GreensvilleJay]

I've been making my own version of the NOCO unit for 20 years,1st gen cost me about $25 to make, last one was a bit over $5, not including the case.Sad when the 'package' costs more than what's inside

 

[Buffalo]

Thanks for all the replies! The "battery tender" carries the nomenclature "Battery Tender", and has received good reviews. I was not aware of the notion of "surface charge" before. I suspect that as the culprit. Y'all stay safe out there!

 

[DaveFromMi]

Mine are "battery charger/maintainers".
Sears Die Hard brand. Probably not made anymore.

 

[Mark_BX25D]

There are "Battery Tenders", and then there are battery tenders.

Heh. I was going to type exactly those words.

I would not trust a HF "battery tender" any further than I could throw it.

Agreed! With enthusiasm!


I've had excellent results from Battery Minders, and have heard good things about the Genius line.

This is not the place to go cheap.

 

[GreensvilleJay]

re: surface charge...
guy related to foam in a glass of beer..... give it a few minutes, and the beer of the foam goes back into the 'real' beer.

 

[Magicman]

I added this one amp charger from WalMart to my generator yesterday. LINK

The yellow indicator lamp lit when I plugged it in and after ~10 minutes, it switched over to the green. My digital voltmeter showed 14.0 volts this morning. It is a very neat/compact unit but I don't really see any need to leave it hooked up.

 

[fried1765]

View attachment 74651
I added this one amp charger from WalMart to my generator yesterday. LINK

The yellow indicator lamp lit when I plugged it in and after ~10 minutes, it switched over to the green. My digital voltmeter showed 14.0 volts this morning. It is a very neat/compact unit but I don't really see any need to leave it hooked up.

I have my doubts about any charger sold under the low price Walmart brand.
Is it UL listed?
I leave my maintenance chargers on whenever I store my tractors (6 mos. -over the Winter), but I buy only high quality units.

 

[Magicman]

Is it UL listed?

Link = ETL Listed

 

[fried1765]

View attachment 74688
ETL Listed

Looks good!

 

[Mark_BX25D]

There is a huge difference between a trickle charger and an intelligent charge maintainer.

A trickle charger will eventually fry your battery if it's left too long.

 

[fried1765]

There is a huge difference between a trickle charger and an intelligent charge maintainer.

A trickle charger will eventually fry your battery if it's left too long.

Agreed!
I am not certain that "trickle chargers" are still even sold anymore.

 

[Mark_BX25D]

Shouldn't be, but they are.