Charging a gel battery from flat?

[PIGGLET]

Just jumped on the bike to go to work and found the battery is completely flat. I'd lef the park light on
I cant get ti to accept a charge from either the standard charger or the optimate or in fact both at the same time.
It's a hawk oddesy that was on the bike when I got it and has given no problems so far. Have I fecked it or should I be able to resurect it?
The really annoying thing is that after reading the bumpstart thread I had intended to sort out some quick connect jumpleads to go in my tool roll next week
No chance of bumping it off, the road is sheet ice

 

[MattW]

You could try jumping it off another vehicle (the high current jolt of another lead acid battery can shock it into life), but don't leave it connected to the donor battery for any longer than is necessary to get the bike started. then go for a ride to try and get some charge into it off the bikes charging system. Then try a charger again.

Unfortunately, whatever you do, you'll need to budget for a new battery before too long - flattening any lead acid battery causes irreparable damage and even if you get it to charge, it'll have reduced capacity.

M

 

[Blackal]

I think all you can do is stick it on a trickle charge for a good while, to see if you can revive it. Be careful of using the "boost" setting because gel batteries should not be allowed to "gas".

If the battery has remained discharged for an extended period (don't ask me how long) - there is a chance you will have now lost some of the originial capacity - even if you manage to resurect it.

Al

 

[Womble]

When I got my Odyssey battery I did a bit of research, and it appears that the one thing that my Optimate III couldn't do was to charge a fully flat AGM battery. I believe that the Optimate IV does this, and that the C-Tek charger sold by Motorworks etc. does it as well. The problem is that you need to trickle the initial charge at a very low level to get the battery to wake up and then charge properly. Unfortunately, I can't now find the information that I read at the time.

The good news is that you may well be able to rescue the battery, but it may need just the right charger, or access to an electronics geek with a bench power supply. As others have said, your chances of success depend on just how long the parking light was left on for.

 

[street_moto]

Pretty tough these Odyssey batteries, I'd go with the suggestion above of maybe jump starting the bike and taking it for a spin to get a bit of life into the battery, it should then accept a trickle charge.
Out of interest how old is the battery?

Regards Dave.

 

[davegs]

Gel's

I think you could be in the brown stuff my old BMW went flat even optimate wouldent revive it only 6 months old at the time

 

[Womble]

I've got the Odyssey Technical Manual here and the batteries look like they do fairly well with a deep discharge:
"(1) German DIN standard test for overdischarge recovery In this test, a PC925 was discharged over 20 hours (0.05C10 rate) to 10.20V. After the discharge, a 5 ohm resistor was placed across the battery terminals and the battery kept in storage for 28 days.
At the end of the storage period, the battery was charged at 13.5V for only 48 hours. A second 0.05C10 discharge yielded 97% of rated capacity, indicating that a low rate 48-hour charge after such a deep discharge was
insufficient; however, the intent of the test is to determine if the battery is recoverable from extremely deep discharges using only a standby float charger. A standard automotive charger at 14.4V would have allowed the battery to recover greater than 97% of its capacity."

So the outlook isn't too bad - a 5 ohm resistor equates to a 30W bulb.

Another webpage states:
"There is another class of chargers that is designed specifically to maintain the battery in a high state of charge. These chargers, such as the 1.25 amp Battery Tender^® from Deltran are not capable of charging a deeply discharged ODYSSEY^® battery. This is due to the fact that these chargers have very low output power. They should only be used either to continuously compensate for parasitic losses or to maintain a trickle charge on a fully charged stored battery."

It may well be that the Optimate, which can't source more than about 0.8A, may just not have enough power to start the charging, and that's why it's unsuitable. By the way, running 2 chargers in parallel won't be very good for either the chargers.

Reading this info, I'd be reaching for the jumpleads.

 

[Blackal]

I've got the By the way, running 2 chargers in parallel won't be very good for either the chargers.

Reading this info, I'd be reaching for the jumpleads.

Some very good info in all the posts

Can't see any harm in running two chargers in parallel, though (why would you want to?) The one with the higher charge voltage will take all/most of the load.

When you jump start a car/bike - you have the starting vehicle charging circuit in parallel with the duff vehicle charging circuit for as long as you have the jump-leads connected.

Al

 

[(RIP) ugg]

just use a motorcycle battery charger, low charge to build it up.

 

[Geno]

I only had mine fitted and it went flat ,my fault , Had to remove battery and work that way ,It would not charge while on the bike ,.Not sure if this is any use .

 

[PIGGLET]

Thanks for all that info guy's I had to abandon it and head into work last night but I've just checked it now and it's showing fully charged on both the chargers.
I'd rather not have to shell out on a new battery at the moment so I'll get some jumpleads as a precaution and see how it goes.
I'm not sure how old the battery is, I dare say there'll be a date stamp on it somewhere but I can't be arsed to look at the mo, it's too damn cold
Whatever happens, whether it resumes duty with no apparent loss of performance or whether it cocks it's toes, I'll let you know

 

[D6]

just dont boost charge a gel battery

 

[vilguy]

Some advanced ish chargers get tricked with the extremely low voltage of a very dead battery and they need to be "shocked" as its called to get them going. Easiest way to sort this is to connect the battery to the charger and then flash the contacts with some leads from another battery...this will get the standard charging process going. Needless to say the dumber the charger the easier it is.. because it doesnt have the auto low voltage cut out system on them.

 

[Blackal]

Thanks for all that info guy's I had to abandon it and head into work last night but I've just checked it now and it's showing fully charged on both the chargers.

Don't be surprised, even if it is showing "healthy" on both chargers - if it turns out to be dead.

(sorry - you probably didn't want to know that )

Al

 

[PIGGLET]

Don't be surprised, even if it is showing "healthy" on both chargers - if it turns out to be dead.

(sorry - you probably didn't want to know that )

Al

Well it's just fired up as normal and done a couple of short runs with no probs. So there

Hopefully it'll be ok, I guess I'll find out in a few days with this cold weather.

It was actually the optimate which started to charge first, after about 20 mins according to the missus. It's quite an old version I got to put on a car about 7 years ago.

 

[Blackal]

Well it's just fired up as normal and done a couple of short runs with no probs. So there

Hopefully it'll be ok, I guess I'll find out in a few days with this cold weather.

It was actually the optimate which started to charge first, after about 20 mins according to the missus. It's quite an old version I got to put on a car about 7 years ago.

Happy days!

(Saves you getting a new battery in your stocking at Christmas)

Al