Community Forums

BlauMax · 08-31-2011, 10:59 AM

Ok folks.. what is a good educated position here? My son has access to frequently changed out batteries in his business. He just emailed me and to told me he would have 8 4D batteries available in 1.5-2 years.. They will be like new and are AGM batteries that need no water and won't outgas or spill.

These batteries are huge and HEAVY.. like 135# or so each. I haven't measured my battery compartment yet.. but, currently have 2 12V batts and 4 (or 6, can't remember) Brown 6V batts.

I believe the 4D are typically used for starting and have something like 220AH. I'm sure 220 AH will last a long time. Not sure how they would last if they are drawn down too far and recharged.. but, what the hey.. if they are free.. and I have access to a bunch of them.. ??

So, not being a battery expert.. I can use some guidance.

BryanL · 08-31-2011, 12:11 PM

There is a reason the business cycles them out and that should not be minimized. They may well serve your needs and be a good deal as your needs are different from that of a business but do know what the deal really is.

AGM's are maintenance free but the cost for that is proper charging and maintenance equipment. You don't want to overcharge them.

If you can make the fit and wire the batteries to get the proper house voltage, you should be OK on that front. Check battery sizes and terminal types and locations very very carefully.

The weight is indeed an issue. One website I saw said there were a couple thousand injuries from batteries every year and something like 40% of those injuries were from improper lifting strains or dropping on sensitive parts.

az bound · 08-31-2011, 12:58 PM

4D AGMs are marine deep cycle batteries and are a good choice for rv use. Paired they will give 400AH. They can be installed in almost any position and will accept a charge rate up to 25 amps. I would say go for it if there is room. They would retail for around $600-$700 each depending on brand.

wa8yxm · 08-31-2011, 02:18 PM

The 8D is roughly equal to a pair of GC2's.. If you can fit 'em, wear 'em in good health.

If you can't fit 'em.. I'll take them off your hands.. I could use one just about now. and I can Make ROOM!!

Lindsay Richards · 08-31-2011, 02:37 PM

I have 2 Lifeline 110 AM AGM batteries and love them. We booddock a lot and they are a great choice. They can even be used on their side or upside down and do not need any maintenance except cleaning terminals. I have two under my entrance steps and it was all I could do to lift then into position. They are heavy. The extra height caused me to have to wiggle them in.

Cat320 · 08-31-2011, 06:08 PM

I have two 4Ds in a sailboat. The reason for the big batteries is (in addition to the 12V lights, water pump, starting the engine, etc) to run the refrigerator which is 12v only and stays on 24/7. In my MH, 4Ds would be an over kill.

wa8yxm · 08-31-2011, 06:27 PM

I do not think a 4D or two would be overkill, I mis-typed in my earlier post.a 4D is about 200 amp hours at the 20 hour rate (alas, Interstate tries to confuse me) so that is an "about".

That is just bit less than the standard GC-2 pair that many motor homes carry.

Watts per pound is... identical for all batteires

Gary RVRoamer · 08-31-2011, 08:10 PM

A single 4D is about the size of two GC2 6v's and has no real advantage over the GC2's. Actually has a bit less amp hours (200 vs 220). But if somebody were giving them to me and I needed to replace my GC2's anyway, it's a heck of a deal. Especially since they are AGMs.

The only question would be why are they getting rid of them. There can be various reasons and they may not be a problem in an RV application, but I would want to know.

BlauMax · 08-31-2011, 08:37 PM

Thanks for the replies folks.. The reason they become available is.. my son works as a chief in a large San Francisco building. They need very reliable power for their computer equipment as well as other uses. They have some large diesel generators that get fired up weekly. After 1.5-2 years they trade out the batteries. It's all about 100% up time. The bat's I've received from him while running a prior building were Gp 27's They were always great.. lasted a long time and were also.. FREE. They are anything but abused...