Effects of "Deep Cycling" your Gel Cells

[Hoghappy]

Anyone else noticed that their gel cells really go down hill in a hurry if they are ran down to almost dead (deep cycling). I'm running the standard 6V 4500mah emergency lighting type of gel cells in my hard working tug. I found that they are having to be replaced after around 10-15 outings due to a extreme performance drop after being deep cycled. These batteries get run hard in the rescue/buoy duties the tug is required to do week in..week out.

I know the 6V gel cell batteries are a lot cheaper than big mah 6 packs...but I need repeatable dependability in my tug. I'm about ready to go back to the battery packs.


Any thoughts on this guys?

[Ghost 2501]

they don't like to be deep cycled. as for the amp pull, it doesn't really matter how much you pull, as long as you dont get the battery warm, or take down below 2v per cell. I took a 6v pack down to 2v once. that killed it

[Swift16]

Gell cells will not work as effective power sources once they're drained deeply. They then become "ballast". They won't charge; they're toxic junk at that point.

[Umi_Ryuzuki]

Most of my newly bought gel cells last 8 years.
The recycled ones are more sketchy... sometimes two years if your lucky.

Had a new rechargable drill battery only last a year... :(

[JOHN SCALE BOAT]

I would recommend you get a chanrger that de-sulphate's the battery. When a lead acid battery is run too low sulpher builds up on the plates and reduces the capacity of the cell. This type of chanrger will charge the battery and break down the sulpher. I use the one below but have the 12V version. I normally get 8-10 years (total life) out the batteries. I only use lead acid in my tugs and I get them used out of old equipment. Check around at the local battery shops that is where I purchased mine.

http://www.batterymart.com/p-batteryminder-6v-1a-battery-charger.html

[iDENTITi]

I would recommend you get a chanrger that de-sulphate's the battery. When a lead acid battery is run too low sulpher builds up on the plates and reduces the capacity of the cell. This type of chanrger will charge the battery and break down the sulpher. I use the one below but have the 12V version. I normally get 8-10 years (total life) out the batteries. I only use lead acid in my tugs and I get them used out of old equipment. Check around at the local battery shops that is where I purchased mine.

http://www.batterymart.com/p-batteryminder-6v-1a-battery-charger.html

De sulphating uses higher amperage charge to do this. I wouldnt reccomend it for model gel cells...
Simple fix though.. Don't run them down completely. Also charge them ASAP after running them to their nominal voltage. They prefer being left fully charged.

[420TEE]

Here's a good source of battery info : http://www.buchmann.ca/

[JOHN SCALE BOAT]

De-Suphication does not use high current it uses high frequency to break down the sulpher. This charger puts out 1 amp max. It is safe to use on small batteries. Most of my gel-cells are 12v 7ah and one 12v 4.5ah have used it on them for years with no problems. This is a smart charger. It will charge at 1 amp till charged then switch over to de-sulphicate were it can be left on the for days with no damage.

[iDENTITi]

De-Suphication does not use high current it uses high frequency to break down the sulpher. This charger puts out 1 amp max. It is safe to use on small batteries. Most of my gel-cells are 12v 7ah and one 12v 4.5ah have used it on them for years with no problems. This is a smart charger. It will charge at 1 amp till charged then switch over to de-sulphicate were it can be left on the for days with no damage.

Hmm.. All the chargers I had for vehicles with de-sulphation tended to "boil-off" the electrolyte. I figured it was them using higher A to clean the plates. Anyway.. Gel cells are supposed to last 2-300 cycles, just as long as you look after them well.

[keith S]

Best advice is to not run them until dead! I have some that are 10 years old and still working just fine. Main thing is to charge at a slow rate and vever fully discharge. I chareg mine with a standard car charger for the 12 volt and a motorcycle charger for the 6 volt. Just do not fast charge to where they get warm as it has the same effect as running them down to low.

[Predreadnut]

The gel cells I use are "normally" used for security systems. In this way, they are continuelly trickle charged at about 1 amp until the power goes off and then they are used to power the security lights. So, I keep mine charged and put them on a trickle charger at 1.5amps for a couple of days every so often. My last set of gel cells lasted 8-9 years.

[Hoghappy]

So what I'm getting out of this is I'm right about the behavior of my gel cells and my experiences are the norm?

Here are my thoughts:

1.) It does not like to be deeply discharged.

2.) If it is run down to dead or almost dead, it will be permanently damaged and probably leave your rescue boat dead and needing rescued the next time you try to use it.

3.) It will last a long time if only used partially (less than 50%?) and then recharged ASAP and stored in a fully charged state.

4.)If your boat is only going to be used to putt around the pond for short to medium battery drain pleasure cruising, this will be a OK choice, but if you need your boat to work all day, dependably, without worry about destroying the battery if you over discharge it...this is not the battery you want.

I tossed all of my 6V gel cells last night. They are NOT what I need/want in my tug/rescue boat. I rewired/replaced the 4500mah gel cell with 2ea 6 packs of 4200mah NiMHs in parallel. This should give me nearly double the run time at about the same weight and I can deep cycle down to about 20% left without hurting them. The initial cost is considerably more, but I have to have reliable/repeatable dependability at the pond in this boat.

Another lesson learned! ;)

[Predreadnut]

I run two 6v 10amh =20amh gell cells in my Bismarck. He is 69in long, over 9in at the beam and weighs around 40 lbs ready for the lake. I run two 540size motors direct drive. I run pretty much wide open most the time. When there's a noticable drop in performance(watch bow wave) I stop for the day. Its not hard to use gell cells without harming them, just dont run the last drop of energy out of them before recharging. With my setup, I've hardly ever got to the drop off of performance. I usually run out of daylight first. :) Also, I need alot of ballast and because of their weight,gell cells were the right choice. Keep those old gell cells, they make good ballast or are good for whenever you need some extra weight.(like holding two objects your glueing together).

[Hoghappy]

A drop in performance is noticeable when you run a boat at full speed especially a speed boat, but I don't run the tug at full speed. It's normally running half power or less so by the time I notice a power shortage it's nearly drained the batteries. That's why I keep hurting them.

I don't want to take the boat out of the water and do voltage checks all the time either. She is always tied up and ready to do a rescue on a moments notice. Quick reaction time can mean the ability to save a boat before it drifts into never never land or even sinks.

Yes...gel cells are just fine for some applications...my rescue tug has proven to not fit in that category.

[Ghost 2501]

crash, check the amp draw on the motors

[Hoghappy]

crash, check the amp draw on the motors

Why? :confused:

[jtrunek]

A drop in performance is noticeable when you run a boat at full speed especially a speed boat, but I don't run the tug at full speed. It's normally running half power or less so by the time I notice a power shortage it's nearly drained the batteries. That's why I keep hurting them.

A while ago, I read something about someone who was having a similar problem. He built a device that would monitor the battery voltage and would briefly interrupt the power to the motors a few times. As a result, the boat would stutter, and he'd know it was time to bring it in to change batteries. Unfortunately, I don't remember the details.