How long does a Optimate III take to recover a deep discharged battery ?

[DaveC]

Hi All

I'm currently trying to recover a completely flat battery with a Optimate III charger.

The battery is a one year old BMW Exide 19Ah 170A battery that was fitted to a 1998 R1100GS-ABS.
Unfortunately the battery was left connected while the bike went unused for 6 months.
Needless to say the battery was completely flat when I began the recovery attempt.

The first 5 recovery attempts failed. The Optimate would 'red light' the battery after attempting the 2 hour recovery mode routine.
On the sixth recovery attempt the Optimate finally managed to break the battery out of deep discharge and then moved into bulk charge mode.

The Optimate has been in bulk charge mode for 6 days now.
The voltage across the battery terminals is 10.5 volts. The current being drawn is 525mA.

I'm wondering about the '170A' figure printed on the side of the battery.
I assuming that this is the total capacity of the battery.
If the battery is rated at 170A total capacity then I guess it could take 13.5 days to fully recover the battery at a constant current rate of 525mA.

I'm interested in hearing anybody else's experience of recovering a similar deep discharged battery with the Optimate III.
In particular how many days of 'bulk charge' did it take before the Optimate gave the battery the fully recovered 'green light' ?

Thanks

DaveC

 

[The Mechanic]

Unfair on the Opti.....mate!

You need something with a bit more oomph like a heavy duty charger. The optimate will get the job done...eventually but in something like two weeks of charging (is it worth it?). There are a number of questions you need to ask yourself before going further.

Is it worth your while to conduct this reclaiming of a potentially unreliable battery?

Would you like to rely upon this battery even if you manage to get it up to full charge?

As this is a normal battery not designed for deep cycle discharge then its reliability now would be very shaky, especially for its age!

 

[Baz]

The battery on my 6 month old bike went flat a couple of months back. Managed to get it jump started and took it down for the 6000 service. The boys at SPC said it was fooked and fitted a new one. So it maybe that you have to replace it.

Baz

 

[DaveC]

I totally agree that the battery will more than likely need replacing.

I called a BMW dealer and they quoted me £80 for a replacement battery.
The local autoparts shop do an equivalent spec Varta battery for £37.

I guess I'm trying to recover the battery I have with the Optimate to see if it can be done.
One of the selling points of the Optimate is that it may be able to recover deep discharge batteries.
As the battery is only one year old I thought it was worth a shot.

DaveC

 

[Greg Masters]

I'm wondering about the '170A' figure printed on the side of the battery.
I assuming that this is the total capacity of the battery.
If the battery is rated at 170A total capacity ....

Whatever 170A means, it isn't the capacity of the battery. From what you said in the first posting, the capacity is 19Ah.

Personally, I'd sling the battery in the direction of the nearest non-ferrous scrap merchant and buy a new one. Then use your Optimate every time you park up - even just overnight. I've done that on my bike since new (4 years old) and the OE battery still fires the ABS every time!



Greg

 

[(RIP) Kaister]

speaking from experience - i'd do exactly the same by the way - try and recover it.
I reckon the optimate will get it going.

However - when you forget to plug the optimate in or you're away from home after a long night ride - the battery will fail in the morning - just when you need it.

But until that time - you'll be thinking how smart you've been and saved £37

.........which is how much AA costs for a year

Phil

 

[Steptoe]

I totally agree that the battery will more than likely need replacing.

I called a BMW dealer and they quoted me £80 for a replacement battery.
As the battery is only one year old I thought it was worth a shot.

DaveC

Dave, there's a two year warrenty with a genuine BM battery

 

[DaveC]

Optimate issues the Battery with a red card after 7 days

Hi all

I checked the Optimate this morning and found the red 'weak' LED lit.
The voltage across the battery terminals read 10.5V.
When I removed the Optimate the voltage across the battery terminals dropped to 8.6 volts.
It would seem that one or more of the cells are non-recoverable with the Optimate.

Ill be ordering a new Varta battery on Monday morning.

Steptoe : Unfortunately returning the battery isn't an option as it was purchased in Switzerland and the cat ate the receipt.
Greg : I have to blame the drink for my theory on battery capacity. A little web searching since has left me wiser on ampere-hours.

Thanks all for the comments and advice.


Dave