AccuMate Resurrection

VIEJO said:

I have a twelve year old AccuMate battery tender that will no longer go into the "float" mode after the battery reaches full charge.... appears to be normal in all other respects. I have already replaced the unit with a BMW charger/tender from Max BMW but I am curious if my AccuMate is repairable (at a reasonable? cost).... hate to give up on a faithful shop warrior too soon.

Thanks,

Viejo

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36654 said:

At $31 and free shipping. https://www.amazon.com/AccuMate-TM-08-ChargeMatic-Battery-charger-maintainer/dp/B0001V0A94

I think the return shipping cost of the old unit would be similar to the cost of the new one. However, I have been faithfully served by one of these units for several decades.

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VIEJO said:

I made a (evidently too) quick check of Amazon before I ordered the BMW charger/tender from Max BMW(at ~90 bucks..... although I do like the free M&M's) but didn't see the one you linked.... that price is good enough I may consider ordering for a back-up/reserve.

Mil Gracias,

Viejo

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36654 said:

It was my pleasure.

BTW - how did you determine that the "float" mode wasn't working? I have an old Battery Tender that started to blink erratically, which made me suspicious of it's health.

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36654 said:

It was my pleasure.

BTW - how did you determine that the "float" mode wasn't working? I have an old Battery Tender that started to blink erratically, which made me suspicious of it's health.

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VIEJO said:

The AGM battery in my K1200RS is about 14 months old and has always been on the AccuMate when not being ridden and the AccuMate was only plugged in when in use. The Accumate had always gone from "charge" to "float" within about three minutes after I returned from riding and in the process never gotten more than slightly warm to the touch. After a ride of about 150 miles last week I connected the AccuMate, confirmed that it was charging, and then stayed in the shop to move crap from one pile to another for a bit..... which turned into about two hours. At one point I noticed that the AccuMate was still at full charge and was warmer than normal to the touch. I metered the battery and found- ~13.9v with the AccuMate connected, ~13.6v disconnected. I then moved the AccuMate to my garden tractor which also had a fairly new battery with the same (metered) results. When I received the new BMW charger/tender from Max BMW I connected it to both the bike and the tractor with positive results.... went to "float" in about three minutes.

It's difficult to meter the output of an AccuMate as it does not release charging voltage unless it senses ~2-3v at the receiving end so you're pretty much confined to metering the voltage at the battery with the AccuMate connected and then disconnected. I'm sure there's a better way to do this test but I don't know what it is..... electrics are not my strong suit. The indicator lights continue to function normally and the only maintenance I have ever done to the unit is to take an icepick and open up the prongs on the male terminals of the auxiliary power port plug charging cable connector and then pack both ends of the charging cable connector with dielectric grease. I did this after I noticed that the AccuMate indicator lights would blink out occasionally when/if I wiggled the connector between the auxiliary power port plug cable and the main charger output cable. This was done about two months ago and I doubt if it precipitated the problem, but I suppose it is possible although the AccuMate performed as expected from the time of the maintenance until last week.

I am not sure what the output amperage of the AccuMate was when I metered the voltage which probably would have been a good indicator of whether or not the unit was easing off on the charging rate as the battery neared full charge or was continuing to deliver full output (which would have eventually fried the battery and God only knows what else downstream).

Viejo

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