MEP-803A Batteries & Long Term Use

[gatorbob]

The last few years of owning my MEP-803A have been particularly tough on batteries. I do live in Florida and have the usual issues with battery life. I don't expect batteries to last longer than 3 years. The issue with my MEP is the batteries are faring much worse than any of my automobiles.

I started with Odyssey AGM batteries and they did make it 2-3 years. But since I didn't get much life out of them for such a high cost, I decided go with a pair of lead acid batteries from Interstate/Costco for $100 each. One of those only lasted one year. I replaced it and my 12V charger said the other battery was good.

I have a BatteryMINDer 24V battery charger connected via the slave port. Somehow the maintainer got disconnected 3 days ago, I reconnected it yesterday, and today my 24V battery maintainer is saying I have a bad cell again. I am assuming the charger could not get the voltage high enough on the 1 year old battery.

Is it correct that to properly maintain these I will need to disconnect them from being in series and independently use a 12V charger on occasion?

Any thoughts on maybe the 6 year old battery charger is causing the problem?

Curious what others experiences are like with battery life and how much/little of a hassle it is for them. I feel like I am missing something.

Thanks

 

[jcollings]

I've had red top batteries installed sense 2017, still going strong. I do keep them on a battery minder 24v charger all the time when not in use.

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[kloppk]

Here in New England my 802 got a pair of Duracell branded 51R's back in 2016 or 2017. They are still going strong.
I use two 12 volt Battery Tender chargers, one on each battery. They are on constant maintenance charge when not in use.
About every 2-4 weeks I start and stop it a 15 times in an afternoon to test my MEP products.

Probably the heat in FL that's taking its toll on your batteries.

From the Crown battery website..
For each 10°F rise in temperature, the life of a sealed lead acid battery is cut in half. Therefore, if a battery in a stationary position that should last for 4 years at normal temps, would last 2 years if exposed 92°F and even less if exposed to typical desert temps of 106°F.

 

[Jeepadict]

I run Napa 51R AGMs with a NOCO dual bank fixed charger/tender. WLA batteries are not worth the time of day, they just cause problems. Each battery is managed individually instead of them being managed as a pair. I used NOCO's cord plug port on the small square panel opposite of the main cord access portal, it lives plugged in 24/7.

Bonus of this setup is with a short extension cord from the new port to the accessory outlet, you can use the NOCO to keep things going in the event of an alternator failure.

 

[jcollings]

Probably the heat in FL that's taking its toll on your batteries.



I'm in Florida South Florida

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[gatorbob]

Thanks for the feedback everyone. @kloppk and @Jeepadict, I don't know how I got it in my head that I could not put the batteries on independent chargers when connected in series.

On WLA vs AGM, the point is well taken. Even my own experience showed the WLAs made it 1 year vs. 2-3 for the AGM. Although, I don't necessarily need to buy the most expensive AGM battery this round. I went with a brand I had very good luck with on Jeeps thinking I would get the same 5-6 years. I will shop around this time given there's only so few companies that actually manufacture batteries these days.

I did not think of the alternator failure scenario. Great point.

 

[msgjd]

everyone has good suggestions and experience of what works for them ...

what works for me is simple... I keep mine hooked in series however the ground cable stays disconnected at all times except when i go to run the unit .. Have gone through 3 or 4 used lead-acid junkyard batteries (700ca-950ca) over the 16 years i have owned my main unit , although this is a MEP003, always in shade, and not in Floridian heat

same thing goes with all the trucks here

 

[2Pbfeet]

Thanks for the feedback everyone. @kloppk and @Jeepadict, I don't know how I got it in my head that I could not put the batteries on independent chargers when connected in series.

On WLA vs AGM, the point is well taken. Even my own experience showed the WLAs made it 1 year vs. 2-3 for the AGM. Although, I don't necessarily need to buy the most expensive AGM battery this round. I went with a brand I had very good luck with on Jeeps thinking I would get the same 5-6 years. I will shop around this time given there's only so few companies that actually manufacture batteries these days.

I did not think of the alternator failure scenario. Great point.

Different size (group) batteries from the same label often have very different lifetimes, so I think it is hard to generalize, so I wouldn't assume that the quality would carry over from one size to another. There was a major supplier that was notorious for having very different capacities and lifetimes for the same battery sold in different geographic areas of the US.

I do think keeping both batteries individually charged helps, though with AGM batteries, I try to remind myself about the lower internal resistance, which has been known to blow charging fuses on alternators, and sometimes the diodes.
https://generators.tpub.com/TB-11-6115-741-24/TB-11-6115-741-240044.htm

I use two 12V solar trickle chargers to keep my batteries individually topped up.

All the best,

2Pbfeet

 

[gatorbob]

Does anyone know what would be a reasonably sized battery charger that would work in the event of an alternator failure?

if I am reading the TM correctly, the fuse is 30A but I am assuming the actual draw would be far less than that. Would the 2x2A @12V mentioned above keep up with the draw under load?

 

[Ray70]

I don't think the 2x2 would suffice. Your fuel pumps and Fuel solenoid will probably draw more than that and slowly deplete the batteries, not to mention the need to recharge the batteries from the start up draw.
I'm sure someone had done a load test on the DC system and can post the typical draw on the DC side.

 

[Light in the Dark]

I believe the regulator on these alternators is rated at 4A, so if you use a NOCO 5A x 2 Bank unit... it should suffice to keep the machine along in a dead alternator situation

Amazon.com

Thats what I use. I power off the side of the case like @Jeepadict does above. So its tied to an extension cord for charging when not being used, and the cord goes away when being used. The benefit to this is in an outage, you just take that same extension cord on the exterior and instead of plugging it into a grid outlet, just plug it into the convenience outlet on the machine while running. The generator will be none the wiser, and it will be running in a closed loop till you need to shut it down.

 

[Ray70]

I believe the regulator on these alternators is rated at 4A,

That doesn't seem right... The Alternator is a 35 or 40A alternator with a 30A fuse at F1 and the ammeter will usually be up in the +20A range briefly after starting the unit.
I think the 5X2 Noco would probably be sufficient as opposed to the 2x2 but I don't think the charging system is 4A, unless I misunderstand what you meant!

 

[2Pbfeet]

I believe the regulator on these alternators is rated at 4A, so if you use a NOCO 5A x 2 Bank unit... it should suffice to keep the machine along in a dead alternator situation

Amazon.com

Thats what I use. I power off the side of the case like @Jeepadict does above. So its tied to an extension cord for charging when not being used, and the cord goes away when being used. The benefit to this is in an outage, you just take that same extension cord on the exterior and instead of plugging it into a grid outlet, just plug it into the convenience outlet on the machine while running. The generator will be none the wiser, and it will be running in a closed loop till you need to shut it down.

I'm curious about the 4A number on the regulator, as doesn't the TM call out the original Prestolite as either 8EM3005CA or 8RM3005CA (which I think is a typo for a 8MR3005CA), specified as 18A, with a 30A fuse, and wasn't that specification for the alternator specification later upgraded to a 35 or 40A version? ( but that's from memory, so don't take it to the bank)

At any rate, to answer the original question, a 2A charger is not going to supply enough to keep the generator running without a working alternator / charging system. I would be looking for at least a 20A 24V charger, though you might be able to squeeze by with less.

All the best,

2Pbfeet

 

[Light in the Dark]

Yeah you are right, the amperage is much higher on the alternator itself. Maybe @Dewie38 can shed some light on the topic.

 

[kloppk]

My 802 running with the panel lights off draws 1.6 amps of 24 volt power.

 

[2Pbfeet]

Yeah you are right, the amperage is much higher on the alternator itself. Maybe @Dewie38 can shed some light on the topic.

I suspect that the alternator mostly idles along. Post engine start up, there will be an in rush to recharge the batteries, higher in AGM batteries, but the total power draw isn't going to be much (as @kloppk showed above). It would be interesting to know if there is/was a use of the generators that need the higher amperage, or whether it was an indirect way to get heavier duty rectifiers that were less prone to failure.

All the best,

2Pbfeet

 

[FarmingSmallKubota]

There is also a cold weather heater for these units that would draw more power and be more demanding on the alternator. also an 803 had larger batteries so would need a little more than 802. Guy Fang had said it before about not even having batteries in most of the units they were operating just a battery cart to start them and away they go. Just a thought

 

[WWRD99]

Thanks for the feedback everyone. @kloppk and @Jeepadict, I don't know how I got it in my head that I could not put the batteries on independent chargers when connected in series.

On WLA vs AGM, the point is well taken. Even my own experience showed the WLAs made it 1 year vs. 2-3 for the AGM. Although, I don't necessarily need to buy the most expensive AGM battery this round. I went with a brand I had very good luck with on Jeeps thinking I would get the same 5-6 years. I will shop around this time given there's only so few companies that actually manufacture batteries these days.

I did not think of the alternator failure scenario. Great point.

One thing I would look at is what type of charger maintainer you get. Some like the NOCO work well with the lead acid as they do have a desulfate in the low charge maintain setup. If you have the lead acid it probably wouldn't hurt to check acid level as well. Brand isn't a very big deal with lead acid since they just put stickers on whomever is selling them.