You sometimes have to take a step back and consider not everyone has this level of intelligence on the issue.
Generac starter battery exploded!
- Thread starter LarryFine
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The diagnostic manual I have (models 4389, 4390, 4456, 4679, 4692, 4758, 4759, 4760) lists two power windings, one excitation winding, one engine run winding (notifies the computer the engine is running), and one battery charge winding.
So there are two charging systems. Doesn't make much sense to me since the 12V outlet + battery charging system are already powered from the trickle charger during standby from the utility sensing lines. Might as well run a seperate line to the transfer switch output so that you don't have the redundant charging circuit. But that would require an extra breaker, extra wire, etc, so maybe its cheaper to just use the charging winding. Or, they intend it to be a fail-safe so if the trickle charger dies you could jump-start the genset and still recharge the battery...
So there are two charging systems. Doesn't make much sense to me since the 12V outlet + battery charging system are already powered from the trickle charger during standby from the utility sensing lines. Might as well run a seperate line to the transfer switch output so that you don't have the redundant charging circuit. But that would require an extra breaker, extra wire, etc, so maybe its cheaper to just use the charging winding. Or, they intend it to be a fail-safe so if the trickle charger dies you could jump-start the genset and still recharge the battery...
K8MHZ
Senior Member
- Occupation
- Electrician
The charging system (alternator) on the generator engine is used to recharge the battery after a start and will provide much more charging current than the external charger. The external chargers are only meant to keep ahead of the self-discharge rate of the battery. As far as magnetos go, remember they were used extensively on motorcycles decades ago and not only did they charge the battery, but the battery was required to make the magneto work, at least on the bikes I had back then.
Flooded cell batteries explode on occasion. I have seen the consequences. I have never seen a battery explode that was not being charged. There have been times where explosions have followed a heavy discharge and that is what got the blame, when in reality the internal resistance of the battery became so low that the charging system had to run at full capacity. The resulting current caused heat which melted parts of the battery, causing an arc and thus the explosion.
Flooded cell batteries explode on occasion. I have seen the consequences. I have never seen a battery explode that was not being charged. There have been times where explosions have followed a heavy discharge and that is what got the blame, when in reality the internal resistance of the battery became so low that the charging system had to run at full capacity. The resulting current caused heat which melted parts of the battery, causing an arc and thus the explosion.
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But this shouldn't matter for an emergency generator intended for home use, where it will only see an occasional start. The trickle charger could have a bulk mode added to it. Just doesn't make sense to add another winding that puts out a few amps that are then sent through a voltage regulator just for the battery, when you already have windings putting out 50+ amps going through their own voltage regulator which the already-necessary trickle charger can use.
K8MHZ
Senior Member
- Occupation
- Electrician
A couple points to ponder:
When the generator starts up it puts a heavy load on the battery, up to 400 amps, for a few seconds. Such a discharge causes the battery to have a low internal impedance requiring more current than a trickle charger can provide. Even if the trickle charger was built to withstand the impedance issue, it won't be able to charge the battery fully for many hours when the possibility exists that the generator may need to be started sooner than that. This is where the alternator on the generator is needed. In fact, I have five 100Ah batteries for my UPS system here at home. Using a 2 amp smart charger which supplies the same current as a trickle charger, or more, it takes about four days for just one battery to charge. The batteries are pulls from Verizon. I have used smart chargers to maintain them, rotating them from use on the UPS to the charger (10 amp with diagnostic mode) and they are now seven years old and still work and have no internal faults. (My charger has a diagnostic mode that detects faults and displays a fault code) If I were to just leave them on the UPS units they serve, the constant current internal charger would shorten the life of the batteries considerably.
When the generator is not in use there is no prime mover for the alternator and the battery, over time, will self discharge. This is where the trickle charger is needed.
I will grant you that the trickle charger is not the best choice for a stand by system. A better choice would be either a smart charger or a float charger, both of which are specifically designed not to damage batteries during charging.
All this will be put to rest soon when nano capacitors replace batteries. They do not self discharge therefore only one charging system will be needed. Until then the problem is NOT the design (except for the use of a constant current trickle charge vs. a float charger) but the quality of the manufacturing and the lack of knowledge or motivation of the owner of the system.
All self starting back up systems need maintenance beyond just starting them up once in a while. If not, they WILL fail to start eventually.
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LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Actually, there was no external sign that anything was wrong. I only saw the damage after removing the front panel of the unit. I'm going back today to install the replacement battery, and will explain everything I've learned so far, and look for the charger to disable it.
What I'd really like to know is whether there's any recourse to pursue with Generac, now that this problem is a few years old with them. In other words, what are their responsibilities? Have they accepted the problem, and is there any warranty or compensation available?
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
She didn't know, but I wouldn't have slapped a replacement in without the call to Generac (no help so far) and posting about it here, with the brain pool.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
It does, or at least did, start once a week for about 12 minutes.
brian john
Senior Member
- Location
- Leesburg, VA
A battery explosion as stated earlier is usually a result of an arc/spark during recharge especially when the electrolyte is low as there is more space for gas. One of the more common reasons for arcing/sparking, loose connections and bad welds typically in the plate to post connection.
1. The chargers supplied by manufactures are JUNK.
2. We always suggest a better charger that the trickle charger supplied by the OEM.
3. With a battery in place check the output voltage and current from the charger.
Float voltage typically is (on a 12 VDC system)13.5, 14.10 (depending on the SG of the electrolyte). Problem is on these cheap chargers there is no voltage adjustment, no current limit and seldom a timer of equalizing.
I would say this is a byproduct of the battery (possible a low end battery*) and cheap charger,, I'd sell a new one and check as noted.
*Like any product some manufactures have design flaws, post welds are one issue some manufactures have struggled with.
1. The chargers supplied by manufactures are JUNK.
2. We always suggest a better charger that the trickle charger supplied by the OEM.
3. With a battery in place check the output voltage and current from the charger.
Float voltage typically is (on a 12 VDC system)13.5, 14.10 (depending on the SG of the electrolyte). Problem is on these cheap chargers there is no voltage adjustment, no current limit and seldom a timer of equalizing.
I would say this is a byproduct of the battery (possible a low end battery*) and cheap charger,, I'd sell a new one and check as noted.
*Like any product some manufactures have design flaws, post welds are one issue some manufactures have struggled with.
K8MHZ
Senior Member
- Occupation
- Electrician
The warranty is only good for two years and does not include starting batteries.
http://www.arcolink.com/images/Warranty.pdf
However.....
This seems to be a common problem with Generac to the point of having a moniker, 'exploding battery syndrome'.
The above was from an entire thread about Generac exploding batteries:
http://zillerelectric.com/forums/showthread.php?t=135&page=3
So, Generac has been made aware of the problem. If any civil recourse is due, it may be possible to accelerate it to class action status. That is one thing that Genarac really does not want to happen, I am sure.
May the force be with you....
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K8MHZ
Senior Member
- Occupation
- Electrician
Here is the exploding battery thread from the beginning.
http://zillerelectric.com/forums/showthread.php?t=135
http://zillerelectric.com/forums/showthread.php?t=135
hillbilly1
Senior Member
- Location
- North Georgia mountains
- Occupation
- Owner/electrical contractor
Temporary is OK, but permanant is not advisable, The battery will quickly run down due to the draw of the control electronics, If you disconnect the charger built into the engine, the battery will also run down while the engine is running with load, the battery also powers an Ice cube relay in the transfer switch that allows the switch to go to "emergency" state. Both chargers are important, and the only time both are on at the same time is when the generator is exercising.
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
the last two 20kva generac I did came with what looked like a wall wart, but had long lamp cords out each end, and the instruction said to connect to a 120 volt circuit supplied from the panel, that this was so the charger would charge in both utility and generator states, it said the generator did not provide charging for the battery. before that the battery charger was built in to the main control board in the generator.
also the newer ones had to have 3 12 volt wires ran to the transfer instead of just the 2 I.E.: 15 and 23 now it's 15-, 15A+(<<charger hooks to these) and 23.
192 and 193 are the 240 utility monitor wires
also the newer ones had to have 3 12 volt wires ran to the transfer instead of just the 2 I.E.: 15 and 23 now it's 15-, 15A+(<<charger hooks to these) and 23.
192 and 193 are the 240 utility monitor wires
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
I left it alone. The no-load voltage was 14.1v, and it dropped to around 13.7 with the engine running on manual. I will go back and check the electrolyte level in about 3 months.
Thanx for all the info and advice, gang!
IMO, that voltage is too high for a "dumb" trickle charger... but I don't know the charging specifics for the battery you are using (and couldn't find any online).I left it alone. The no-load voltage was 14.1v, and it dropped to around 13.7 with the engine running on manual. I will go back and check the electrolyte level in about 3 months.
Thanx for all the info and advice, gang!
As a reference, compare to charging information published for Optima batteries: http://www.optimabatteries.com/product_support/charging.php
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
That voltage is not all that bad for a starting type wet cell(car battery) as most cars are set at 14.2 volts on there regulators, but a deep cycle type should be more around 13.6v which is not what you would use in a generator anyways, I use a heavy duty 26R commercial type starting battery that has heaver plates and is more shock resistant, I have one that has been in use for about 7 years and still checks out good.
These types will have removable cell caps where the battery can be maintained.
lazg65
New member
- Location
- cutler bay, florida
Hi, I had the same this happen to me when I tried to start a generator that was in overcrank. The generator when I tried to start it, the battery exploded like a shoot gun going off. I was lucky that I always stand aside the unit when I start it and It saved me from an acid bath. Or how about the owner trying to start it who does not know protocal. The unit was a 45k generac, with a 2 years old blue discount auto battery. I now do not wait anymore for the battery over a year to change.
I have the 15/13 kw Generac standby generator installed in 5/2006 with a new battery. Everything was fine until 6/2008 when the battery exploded when running the weekly test. Noticed very little battery fluid so cleaned everything up and replaced battery. Everything fine until 11/2009 when unit would not crank during self test. Battery voltage was low but unit would start fine with a good battery. Tested the charging voltage at the battery cables and its 25 volts. Looks like the built in battery charger in the gen is overcharging and killing the battery. Will have service tech check unit but I suspect charger or voltage regulator is bad.
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
None of the guardian 8K thru 20K have a alternator on the motor to charge the battery, but the quite source 22k and above do as well as the commercial lines, rule of thumb is if it has a 4 cylinder or more it has a built in 30 amp charger in the motor, if it is a one or two cylinder it doesn't, they all have the little ugly wall-wart but it doesn't plug in as it has leads to tie into the transfer switch on the panel side, they even supply the fuse block and jumpers for it, I have never had a battery explode out of the many of these we install, but we were called on one that did, but it was an installation problem, (the home owner had turned the battery clamp so that the positive could hit the side wall and the battery vibrated over till it shorted out and caused the battery to explode.
I use commercial heavy duty grade battery's that have maintenance caps on them, and I agree the charger they supply is a bit for the weary, it can be used from 120 to 277 volts and if the right size battery is used (26R 525 CCA),it will maintain about a 14.2-3 level with the generator in auto mode, if put in off, the voltage can go up without a load.
they are a constant charge trickle charger with a 1.5-2 amp out, if you read the instructions for any maintenance free battery it will say to use a automatic battery maintainer not a trickle charger that is more designed for deep cycle battery's and commercial grade that can be maintained, and you should stop having problems.
If you chose to use the trickle charge supplied by Generac, then get the correct battery, as I listed above.
I use commercial heavy duty grade battery's that have maintenance caps on them, and I agree the charger they supply is a bit for the weary, it can be used from 120 to 277 volts and if the right size battery is used (26R 525 CCA),it will maintain about a 14.2-3 level with the generator in auto mode, if put in off, the voltage can go up without a load.
they are a constant charge trickle charger with a 1.5-2 amp out, if you read the instructions for any maintenance free battery it will say to use a automatic battery maintainer not a trickle charger that is more designed for deep cycle battery's and commercial grade that can be maintained, and you should stop having problems.
If you chose to use the trickle charge supplied by Generac, then get the correct battery, as I listed above.
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