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Old 05-19-2015, 02:32 AM   #1
Brand: Thor Motor Coach
Model: Citation Sprinter 24SR
State: Oregon
Posts: 56
THOR #972
Battery Success

Our 2015 Citation Sprinter SR came with Harrison brand group 27 batteries. I picked it up in July, 2014, drove home (2100 miles) then to SoCal without issues but was hooked to shore power most stops.

Late last year we did a couple dry camping trips and found the batteries drained pretty quickly (within 48 hours with just short periods of night-time lighting).

I removed the batteries over the past winter and left on a 2amp trickle charger. Soon after re-installing the batteries were dead within 12 hours. I disconnected the 12V TV and pulled the fuse for the radio and still only got 12 hours or less from them.

I've replaced with 2 Optima group 24 (much easier to install and remove). As of today, 4 days after replacing, the Optima's are 2/3ds charged, even after leaving fan and bathroom light on so I figure the Harris batteries were the issue and not some unknown parasitic drain.

I should have checked the Harris batteries before storing; it's possible they were in the coach or sitting in the factory for a long time before it was sold. In any case, I think the Optima's will take good care of us.

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Old 05-19-2015, 02:58 AM   #2
Senior Member
thor293's Avatar
Brand: Thor Motor Coach
Model: A.C.E 29.3
State: Ohio
Posts: 610
THOR #1620
My Harris batteries are crap too. Soon as you take them off charge the voltage drops to 12.35-12.4

2015 Thor A.C.E. 29.3
2014 Honda CRV Toad
Ohio FMCA 317123
Camping World Indianapolis, worst dealer EVER experienced
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Old 05-19-2015, 11:24 AM   #3
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Brand: Thor Motor Coach
Model: 2011 Four Winds 28Z
State: Michigan
Posts: 1,273
THOR #531
One issue with AGM batteries such as the Optima is if your built-in charger does not have the ability to charge AGM, they can damage the batteries.

AGM batteries must be charged at a lower trickle charge rate (in overcharge) than typical lead acid batteries, or they can become damaged.

This typically requires a charger having an AGM mode (which usually must be switched over manually). Consequently, when upgrading to AGM, you may also have to upgrade the charger as well.

You don't normally see an over-charge (trickle charge) condition when putting AGM batteries in a vehicle as the main engine battery. The alternator only charges the battery as the engine is running, so the battery really does not go into overcharge mode.

Of course this is different with RV house batteries when they are sitting on a charger - and there is no significant load on it - the batteries will at some point likely go into overcharge mode.

Just something you should be aware of when going to AGM batteries.
The only thing that works on a RV is the owner...
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